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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.4014 | Ralph Kraft | R. P. Kraft, W. R. Forman, M. J. Hardcastle, C. Jones, P. E. J. Nulsen | The Disturbed 17 keV Cluster Associated with the Radio Galaxy 3C 438 | 13 pages, 4 figures, 1 table - accepted for publication in the
Astrophysical Journal Letters | null | 10.1086/520955 | null | astro-ph | null | We present results from a {\em Chandra} observation of the cluster gas
associated with the FR II radio galaxy 3C 438. This radio galaxy is embedded
within a massive cluster with gas temperature $\sim$17 keV and bolometric
luminosity of 6$\times10^{45}$ ergs s$^{-1}$. It is unclear if this high
temperature represents the gravitational mass of the cluster, or if this is an
already high ($\sim$ 11 keV) temperature cluster that has been heated
transiently. We detect a surface brightness discontinuity in the gas that
extends $\sim$600 kpc through the cluster. The radio galaxy 3C 438 is too small
($\sim$110 kpc across) and too weak to have created this large disturbance in
the gas. The discontinuity must be the result of either an extremely powerful
nuclear outburst or the major merger of two massive clusters. If the observed
features are the result of a nuclear outburst, it must be from an earlier epoch
of unusually energetic nuclear activity. However, the energy required
($\sim10^{63}$ ergs) to move the gas on the observed spatial scales strongly
supports the merger hypothesis. In either scenario, this is one of the most
extreme events in the local Universe.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:42:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kraft",
"R. P.",
""
],
[
"Forman",
"W. R.",
""
],
[
"Hardcastle",
"M. J.",
""
],
[
"Jones",
"C.",
""
],
[
"Nulsen",
"P. E. J.",
""
]
] |
0706.4015 | Franck Petit | Christian Boulinier (LaRIA), Franck Petit (LaRIA) | Self-Stabilizing Wavelets and r-Hops Coordination | null | Rapport Interne (01/04/2007) | null | null | cs.DC | null | We introduce a simple tool called the wavelet (or, r-wavelet) scheme.
Wavelets deals with coordination among processes which are at most r hops away
of each other. We present a selfstabilizing solution for this scheme. Our
solution requires no underlying structure and works in arbritrary anonymous
networks, i.e., no process identifier is required. Moreover, our solution works
under any (even unfair) daemon. Next, we use the wavelet scheme to design
self-stabilizing layer clocks. We show that they provide an efficient device in
the design of local coordination problems at distance r, i.e., r-barrier
synchronization and r-local resource allocation (LRA) such as r-local mutual
exclusion (LME), r-group mutual exclusion (GME), and r-Reader/Writers. Some
solutions to the r-LRA problem (e.g., r-LME) also provide transformers to
transform algorithms written assuming any r-central daemon into algorithms
working with any distributed daemon.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:53:06 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Boulinier",
"Christian",
"",
"LaRIA"
],
[
"Petit",
"Franck",
"",
"LaRIA"
]
] |
0706.4016 | Mauro R. Cosentino | Mauro R. Cosentino (for the Star Collaboration) | Heavy-Quarkonia in the Star Experiment | Proceedings of X Hadron Physics, submitted to Int. Journal of Mod.
Phys. E | null | 10.1142/S021830130700880X | null | nucl-ex | null | Heavy Quarkonium states modifications in relativistic heavy ion collisions
have been of great interest since the proposal by Matsui and Satz of J/psi
suppression as a signature of Quark-Gluon Plasma (QGP) formation. Recent
studies suggest that the excited states chi_c, psi(2S) and Upsilon(3S) melt
sequentially[1,2] and the amount of observed suppression depends on the state
and medium conditions. Therefore, this suppression pattern may be used as a
probe of the medium temperature. In this work we present preliminary results on
the charmonium and bottomnium measurements performed by the STAR experiment at
RHIC for p+p and Cu+Cu collisions at sqrt(s_{NN})=200GeV
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:54:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cosentino",
"Mauro R.",
"",
"for the Star Collaboration"
]
] |
0706.4017 | Cedran Bomhof | C. J. Bomhof, P. J. Mulders | The Role of Gauge Invariance in Single-Spin Asymmetries | Talk presented at the 15th International Workshop on Deep-Inelastic
Scattering and Related Subjects (DIS 2007), April 16-20, 2007, Munich,
Germany | null | null | null | hep-ph | null | We argue that through the Wilson lines, gauge invariance has as an effect
that the hard functions in weighted spin-asymmetries in hadronic scattering
processes are given by gluonic pole cross sections, rather than the usual
partonic cross sections.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:55:34 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Bomhof",
"C. J.",
""
],
[
"Mulders",
"P. J.",
""
]
] |
0706.4018 | Catherine Rainer | Rainer Buckdahn, Jin Ma, Catherine Rainer | Stochastic control problems for systems driven by normal martingales | Published in at http://dx.doi.org/10.1214/07-AAP467 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org) | Annals of Applied Probability 2008, Vol. 18, No. 2, 632-663 | 10.1214/07-AAP467 | IMS-AAP-AAP467 | math.PR math.OC | null | In this paper we study a class of stochastic control problems in which the
control of the jump size is essential. Such a model is a generalized version
for various applied problems ranging from optimal reinsurance selections for
general insurance models to queueing theory. The main novel point of such a
control problem is that by changing the jump size of the system, one
essentially changes the type of the driving martingale. Such a feature does not
seem to have been investigated in any existing stochastic control literature.
We shall first provide a rigorous theoretical foundation for the control
problem by establishing an existence result for the multidimensional structure
equation on a Wiener--Poisson space, given an arbitrary bounded jump size
control process; and by providing an auxiliary counterexample showing the
nonuniqueness for such solutions. Based on these theoretical results, we then
formulate the control problem and prove the Bellman principle, and derive the
corresponding Hamilton--Jacobi--Bellman (HJB) equation, which in this case is a
mixed second-order partial differential/difference equation. Finally, we prove
a uniqueness result for the viscosity solution of such an HJB equation.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:03:16 GMT"
},
{
"version": "v2",
"created": "Fri, 4 Apr 2008 05:56:05 GMT"
}
] | 2008-04-04T00:00:00 | [
[
"Buckdahn",
"Rainer",
""
],
[
"Ma",
"Jin",
""
],
[
"Rainer",
"Catherine",
""
]
] |
0706.4019 | Ian Hambleton | Ian Hambleton and Wolfgang Lueck | Induction and computation of Bass Nil Groups for finite groups | 21 pages. Final version | Pure and Applied Mathematics Quarterly, Volume 8, Number 1,
Special Issue: In honor of F. Thomas Farrell and Lowell E. Jones, Part 1 of
2, 199-219, 2012 | null | null | math.KT math.AT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let G be a finite group. We show that the Bass Nil-groups $NK_n(RG)$, $n \in
Z$, are generated from the p-subgroups of G by induction maps, certain twisting
maps depending on elements in the centralizers of the p-subgroups, and the
Verschiebung homomorphisms. As a consequence, the groups $NK_n(RG)$ are
generated by induction from elementary subgroups. For $NK_0(ZG)$ we get an
improved estimate of the torsion exponent.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:18:14 GMT"
},
{
"version": "v2",
"created": "Tue, 1 Apr 2008 18:01:19 GMT"
},
{
"version": "v3",
"created": "Fri, 20 Aug 2010 14:47:42 GMT"
}
] | 2010-08-23T00:00:00 | [
[
"Hambleton",
"Ian",
""
],
[
"Lueck",
"Wolfgang",
""
]
] |
0706.4020 | Jeremy Dunning-Davies | J. Dunning-Davies | Extensivity and Relativistic Thermodynamics | 7 pages | null | null | null | physics.gen-ph | null | The mathematical properties associated with the widely accepted concept of
the extensivity of many of the common thermodynamic variables are examined and
some of their consequences considered. The possible conflict between some of
these and currently accepted results of special relativistic thermodynamics is
highlighted. Although several questions are raised, answers are not advanced as
this seems an area demanding calm, widespread reflection which could
conceivably lead to radical revision of part, or parts, of theoretical physics.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:11:11 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Dunning-Davies",
"J.",
""
]
] |
0706.4021 | Andrea Rapisarda | A. Pluchino, A. Rapisarda and C. Tsallis | Nonergodicity and Central Limit Behavior for Long-range Hamiltonians | 6 pages 7 figures. Improved version accepted for publication on
Europhysics Letters | Europhysics Letters, 80 (2007) 26002 | 10.1209/0295-5075/80/26002 | null | cond-mat.stat-mech astro-ph nucl-th physics.data-an | null | We present a molecular dynamics test of the Central Limit Theorem (CLT) in a
paradigmatic long-range-interacting many-body classical Hamiltonian system, the
HMF model. We calculate sums of velocities at equidistant times along
deterministic trajectories for different sizes and energy densities. We show
that, when the system is in a chaotic regime (specifically, at thermal
equilibrium), ergodicity is essentially verified, and the Pdfs of the sums
appear to be Gaussians, consistently with the standard CLT. When the system is,
instead, only weakly chaotic (specifically, along longstanding metastable
Quasi-Stationary States), nonergodicity (i.e., discrepant ensemble and time
averages) is observed, and robust $q$-Gaussian attractors emerge, consistently
with recently proved generalizations of the CLT.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:16:17 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Jul 2007 13:34:11 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Sep 2007 08:20:54 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Pluchino",
"A.",
""
],
[
"Rapisarda",
"A.",
""
],
[
"Tsallis",
"C.",
""
]
] |
0706.4022 | Delphine Porquet | Delphine Porquet (OAS), Phil Uttley (School of Physics and Astronomy,
University of Southampton, Uk), James N. Reeves (LHEA, Goddard, Usa, Johns
Hopkins University, Usa, University of Keele, Uk), Alex Markowitz (LHEA,
Goddard, Usa, Johns Hopkins University, Usa), Stefano Bianchi (Universita
Degli Studi Roma Tre, Italy), Nicolas Grosso (OAS), Lance Miller (University
of Oxford, Uk), Sandrine Deluit (CESR), Ian M. George (University of
Maryland) | A 100ks XMM-Newton view of the Seyfert 1.8 ESO113-G010. I. Discovery of
large X-ray variability and study of the FeKalpha line complex | Accepted for publication in A&A, 10 pages, 11 figures, 2 tables | null | 10.1051/0004-6361:20077699 | null | astro-ph | null | (Abridged) We present here a long (100ks) XMM-Newton follow-up of the Seyfert
1.8 galaxy ESO113-G010 performed in November 2005, in order to study over a
longer time-scale its main X-ray properties. The source was found in a
higher/softer time-averaged flux state, and timing analysis of this source
reveals strong, rapid variability. The Power Spectral Density (PSD) analysis
indicates (at 95% c.l.) a break at 3.7 x 10^-4 Hz. This cut-off frequency is
comparable to those measured in some other rapidly-variable Seyferts, such as
MCG-6-30-15 and NGC4051. From the mass-luminosity-time-scale, we infer that
M_BH ranges from 4 x 10^6 - 10^7 M_odot and the source is accreting at or close
to the Eddington rate (or even higher). The existing data cannot distinguish
between spectral pivoting of the continuum and a two-component origin for the
spectral softening, primarily because the data do not span a broad enough flux
range. In the case of the two-component model, the fractional offsets measured
in the flux-flux plots increase significantly toward higher energies (similar
to what is observed in MCG-6-30-15) as expected if there exists a constant
reflection component. Contrary to May 2001, no significant highly redshifted
emission line is observed (which might be related to the source flux level),
while two narrow emission lines at about 6.5keV and 7keV are observed. The S/N
is not high enough to establish if the lines are variable or constant. As
already suggested by the 2001 observation, no significant constant narrow
6.4keV FeK line (EW~32eV) is observed, hence excluding any dominant emission
from distant cold matter such as a torus in this Seyfert type 1.8 galaxy.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:17:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Porquet",
"Delphine",
"",
"OAS"
],
[
"Uttley",
"Phil",
"",
"School of Physics and Astronomy,\n University of Southampton, Uk"
],
[
"Reeves",
"James N.",
"",
"LHEA, Goddard, Usa, Johns\n Hopkins University, Usa, University of Keele, Uk"
],
[
"Markowitz",
"Alex",
"",
"LHEA,\n Goddard, Usa, Johns Hopkins University, Usa"
],
[
"Bianchi",
"Stefano",
"",
"Universita\n Degli Studi Roma Tre, Italy"
],
[
"Grosso",
"Nicolas",
"",
"OAS"
],
[
"Miller",
"Lance",
"",
"University\n of Oxford, Uk"
],
[
"Deluit",
"Sandrine",
"",
"CESR"
],
[
"George",
"Ian M.",
"",
"University of\n Maryland"
]
] |
0706.4023 | C. Hanhart | V. Baru, J. Haidenbauer, C. Hanhart, A. Kudryavtsev, V. Lensky, and
U.-G. Mei{\ss}ner | Role of the Delta(1232) in pion-deuteron scattering at threshold within
chiral effective field theory | 11 pages | Phys.Lett.B659:184-191,2008 | 10.1016/j.physletb.2007.10.063 | FZJ-IKP(TH)-2005-22, HISKP-TH-07-19 | nucl-th hep-ph | null | We investigate the role of the delta isobar in the reaction $\pi d\to \pi d$
at threshold in chiral effective field theory. We discuss the corresponding
power counting and argue that this calculation completes the evaluation of
diagrams up to the order (m_pi/M_N)^(3/2), with m_pi (M_N) for the pion
(nucleon) mass. The net effect of all delta contributions at this order to the
pion-deuteron scattering length is (2.4 +/- 0.4)x 10^(-3) m_pi^{-1}.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:28:38 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Baru",
"V.",
""
],
[
"Haidenbauer",
"J.",
""
],
[
"Hanhart",
"C.",
""
],
[
"Kudryavtsev",
"A.",
""
],
[
"Lensky",
"V.",
""
],
[
"Meißner",
"U. -G.",
""
]
] |
0706.4024 | John H. Debes | J.H. Debes, S. Sigurdsson, B. Hansen | Cool Customers in the Stellar Graveyard IV: Spitzer Search for Mid-IR
excesses Around Five DAs | 18 pages, 8 figures, Accepted to AJ | Astron.J.134:1662-1670,2007 | 10.1086/521394 | null | astro-ph | null | Hydrogen atmosphere white dwarfs with metal lines, so-called DAZs, require
external accretion of material to explain the presence of weak metal line
absorption in their photospheres. The source of this material is currently
unknown, but could come from the interstellar medium, unseen companions, or
relic planetesimals from asteroid belt or Kuiper belt analogues. Accurate
mid-infrared photometry of these white dwarfs provide additional information to
solve the mystery of this accretion and to look for evidence of planetary
systems that have survived post main sequence evolution. We present {\em
Spitzer} IRAC photometry accurate to $\sim$3% for four DAZs and one DA with
circumstellar absorption lines in the UV. We search for excesses due to unseen
companions or circumstellar dust disks. We use {\em Hubble Space Telescope}
NICMOS imaging of these white dwarfs to gauge the level of background
contamination to our targets as well as rule out common proper motion
companions to WD 1620-391. All of our targets show no excesses due to
companions $>$20 M$_{J}$, ruling out all but very low mass companions to these
white dwarfs at all separations. No excesses due to circumstellar disks are
observed, and we place limits on what types of disks may still be present.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:30:14 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Debes",
"J. H.",
""
],
[
"Sigurdsson",
"S.",
""
],
[
"Hansen",
"B.",
""
]
] |
0706.4025 | Michael Sarrazin | Fabrice Petit, Michael Sarrazin | Plausible "faster-than-light" displacements in a two-sheeted spacetime | 17 pages, 1 figure. Final version. Accepted for publication in Phys.
Rev. D | Phys.Rev.D76:085005,2007 | 10.1103/PhysRevD.76.085005 | null | hep-th gr-qc | null | In this paper, we explore the implications of a two-point discretization of
an extra-dimension in a five-dimensional quantum setup. We adopt a pragmatic
attitude by considering the dynamics of spin-half particles through the
simplest possible extension of the existing Dirac and Pauli equations. It is
shown that the benefit of this approach is to predict new physical phenomena
while maintaining the number of constitutive hypothesis at minimum. As the most
striking feature of the model, we demonstrate the possibility of fermionic
matter oscillations between the two four-dimensional sections and hyper-fast
displacements in case of asymmetric warping (without conflicting special
relativity). This result, similar to previous reported ones in brane-world
theories, is completely original as it is derived by using quantum mechanics
only without recourse to general relativity and bulk geodesics calculation. The
model allows causal contact between normally disconnected regions. If it proves
to be physically founded, its practical aspects could have deep implications
for the search of extra-dimensions.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:31:41 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 18:55:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Petit",
"Fabrice",
""
],
[
"Sarrazin",
"Michael",
""
]
] |
0706.4026 | Susan Schadmand | S. Schadmand | Two Pion Production from Nuclei | Proceedings of YKIS2006: Yukawa Interantional Symposium 2006 -
Excited Hadrons adn Hadronic Matter, Kyoto, Japan, 4.-8.Dec.2006 | Prog.Theor.Phys.Suppl.168:466-469,2007 | 10.1143/PTPS.168.466 | null | nucl-ex | null | Differences in the photoproduction of mesons on the free proton and on nuclei
are expected to reveal changes in the properties of hadrons. Double pion
photoproduction from nuclei has been used to investigate the in medium
modification of meson-meson interactions with the TAPS photon spectrometer at
MAMI-B. Recent developments are reported.
Hadron-hadron interactions and meson production and decays involving light
nuclei are also studied in hadron induced experiments. In particular, the
physics program of the new WASA-at-COSY facility includes double pion
production from light nuclei. Here, the efforts focus on the ABC effect, the
puzzling low-mass enhancement in the pi-pi invariant mass spectrum, first
observed in inclusive measurements of two-pion production in nuclear
collisions.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:31:53 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 13:42:26 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Schadmand",
"S.",
""
]
] |
0706.4027 | Davide Ceresoli | D. Ceresoli, T. Zykova-Timan, U. Tartaglino and E. Tosatti | Alkali Halide Surfaces Near Melting: Wetting and Nanofriction Properties | 9 pages, 6 figures; High Temperature Capillarity 2007 (HTC-07)
proceeding | Materials Science and Engineering: A Volume 495, Issues 1-2, 15
November 2008, Pages 32-35 | 10.1016/j.msea.2007.09.092 | null | cond-mat.mtrl-sci cond-mat.soft cond-mat.stat-mech | null | Alkali halide (100) crystal surfaces are poorly wetted by their own melt at
the triple point. We carried out simulations for NaCl(100) within the well
tested BMHFT model potential. Calculations of the solid-vapor, solid-liquid and
liquid-vapor free energies showed that solid NaCl(100) is a non-melting
surface, and explain its bad wetting in detail.
The extreme stability of NaCl(100) is ideal for a study of the nanofriction
in the high temperature regime, close to and even above the bulk melting
temperature (T_M). Our simulations reveal in this regime two distinct and
opposite phenomena for plowing and for grazing friction. We found a frictional
drop close to T_M for deep ploughing and wear, but on the contrary a frictional
rise for grazing, wearless sliding. For both phenomena we obtain a fresh
microscopic understanding, relating the former to ``skating'' through a local
liquid cloud, the latter to softening of the free substrate surface. It is
argued that both phenomena, to be pursued experimentally, should be much more
general than the specific NaCl surface case. Most metals in particular
possessing one or more close packed non-melting surface, such as Pb, Al or
Au(111), should behave quite similarly.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:34:49 GMT"
}
] | 2008-09-25T00:00:00 | [
[
"Ceresoli",
"D.",
""
],
[
"Zykova-Timan",
"T.",
""
],
[
"Tartaglino",
"U.",
""
],
[
"Tosatti",
"E.",
""
]
] |
0706.4028 | Sergiy Khan A | S. A. Khan, D. V. Shulyak | Theoretical analysis of the atmospheres of CP stars. Effects of the
individual abundance patterns | 18 pages, 9 figures | Astron.Astrophys.469:1083-1100,2007 | 10.1051/0004-6361:20077192 | null | astro-ph | null | Context. See abstract in the paper.
Aims. See abstract in the paper.
Methods. See abstract in the paper.
Results. We present a homogeneous study of model atmosphere temperature
structure, energy distribution, photometric indices in the uvbybeta and Delta_a
systems, hydrogen line profiles, and the abundance determination procedure as
it applies to CP stars. In particular, we found that Si, Cr and Fe are the main
elements to influence model atmospheres of CP stars, and thus to be considered
in order to assess the adequacy of model atmospheres with scaled solar
abundances in application to CP stars. We provide a theoretical explanation of
the robust property of the Delta_a photometric system to recognize CP stars
with peculiar Fe content. Also, the results of our numerical tests using model
atmospheres with one or several elements overabundant (Si and Fe by +1 dex, Cr
by +2 dex) suggest that the uncertainty of abundance analysis in the
atmospheres of CP stars using models with scaled abundances is less than
plus/minus 0.25 dex. If the same homogeneous models are used for the abundance
stratification analysis then we find that the uncertainty of the value of the
vertical abundance gradient is within an 0.4 dex error bar.
Conclusions. Model atmospheres with individual abundance patterns should be
used in order to match the actual anomalies of CP stars and minimize analysis
errors.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:44:15 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Khan",
"S. A.",
""
],
[
"Shulyak",
"D. V.",
""
]
] |
0706.4029 | Francesco Nesi | F. Nesi, M. Grifoni, and E. Paladino | Dynamics of a qubit coupled to a broadened harmonic mode at finite
detuning | 17 pages, 6 figures | New Journ. Phys., 9, 316 (2007) | 10.1088/1367-2630/9/9/316 | null | cond-mat.stat-mech cond-mat.other | null | We study the dynamics of a symmetric two-level system strongly coupled to a
broadened harmonic mode. Upon mapping the problem onto a spin-boson model with
peaked spectral density, we show how analytic solutions can be obtained, at
arbitrary detuning and finite temperatures, in the case of large Q-factors of
the oscillator. In general {\em two} or more oscillation frequencies of the
two-level particle are observed as a consequence of the entanglement with the
oscillator. Our approximated analytical solution well agrees with numerical
predictions obtained within the non-interacting blip approximation.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:38:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Nesi",
"F.",
""
],
[
"Grifoni",
"M.",
""
],
[
"Paladino",
"E.",
""
]
] |
0706.4030 | Victor Novikov a | Victor Novikov | On the Pauli principle violation in QFT | Presented at Les Rencontres de Physique de La Vallee d'Aoste, March
4-10, 2007, La Thuile, Aosta Valley, Italy | null | null | null | hep-ph | null | We propose a new mechanism for a ''small" violation of Pauli Principle in the
framework of Quantum Field Theory. Instead of modification of algebra -
commutation relations for fields - we introduce spontaneous violation of Pauli
Principle which is proportional to the vacuum fermionic condensate.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:24:41 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Novikov",
"Victor",
""
]
] |
0706.4031 | Michael Ivanov A | Michael A. Ivanov | Small effects of low-energy quantum gravity | 4 pages, 2 figures, Latex; poster contribution to the XIII
International Conference "Physical Interpretations of Relativity Theory",
Moscow, 2-5 July 2007 | null | null | null | hep-th astro-ph gr-qc | null | Small effects of quantum gravity on the scale $\sim 10^{-3} eV$ and their
cosmological consequences are discussed and compared with observations of
supernovae 1a, gamma-ray bursts and galaxies.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:44:38 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Ivanov",
"Michael A.",
""
]
] |
0706.4032 | Marco Thiel | Geoffrey Robinson and Marco Thiel | How much information about a dynamical system do its recurrences
contain? | 9 pages, 0 figures | null | null | null | math.DS | null | We show that, under suitable assumptions, Poincare recurrences of a dynamical
system determine its topology in phase space. Therefore, dynamical systems with
the same recurrences are topologically equivalent.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:05:53 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Jul 2007 11:14:06 GMT"
}
] | 2007-07-04T00:00:00 | [
[
"Robinson",
"Geoffrey",
""
],
[
"Thiel",
"Marco",
""
]
] |
0706.4033 | Bin Wang | Chang Feng, Bin Wang, Yungui Gong and Ru-Keng Su | Testing the viability of the interacting holographic dark energy model
by using combined observational constraints | 15 pages, 9 figures, accepted for publication in JCAP | JCAP 0709:005,2007 | 10.1088/1475-7516/2007/09/005 | null | astro-ph gr-qc hep-th | null | Using the data coming from the new 182 Gold type Ia supernova samples, the
shift parameter of the Cosmic Microwave Background given by the three-year
Wilkinson Microwave Anisotropy Probe observations, and the baryon acoustic
oscillation measurement from the Sloan Digital Sky Survey, $H(z)$ and lookback
time measurements, we have performed a statistical joint analysis of the
interacting holographic dark energy model. Consistent parameter estimations
show us that the interacting holographic dark energy model is a viable
candidate to explain the observed acceleration of our universe.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:03:57 GMT"
},
{
"version": "v2",
"created": "Wed, 15 Aug 2007 20:11:39 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Feng",
"Chang",
""
],
[
"Wang",
"Bin",
""
],
[
"Gong",
"Yungui",
""
],
[
"Su",
"Ru-Keng",
""
]
] |
0706.4034 | Jozsef Cserti | Jozsef Cserti, Andras Palyi, Csaba Peterfalvi | Caustics due to Negative Refractive Index in Circular Graphene p-n
Junctions | 4 pages, 5 figures | Phys. Rev. Lett. 99, 246801 (2007) | 10.1103/PhysRevLett.99.246801 | null | cond-mat.mes-hall | null | We show that the wavefunctions form caustics in circular graphene p-n
junctions which in the framework of geometrical optics can be interpreted with
negative refractive index.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:16:15 GMT"
}
] | 2007-12-12T00:00:00 | [
[
"Cserti",
"Jozsef",
""
],
[
"Palyi",
"Andras",
""
],
[
"Peterfalvi",
"Csaba",
""
]
] |
0706.4035 | Sapon Tanachaiwiwat | Sapon Tanachaiwiwat, Ahmed Helmy | Encounter-based worms: Analysis and Defense | Submitted to a journal | null | null | null | cs.NI cs.CR | null | Encounter-based network is a frequently-disconnected wireless ad-hoc network
requiring immediate neighbors to store and forward aggregated data for
information disseminations. Using traditional approaches such as gateways or
firewalls for deterring worm propagation in encounter-based networks is
inappropriate. We propose the worm interaction approach that relies upon
automated beneficial worm generation aiming to alleviate problems of worm
propagations in such networks. To understand the dynamic of worm interactions
and its performance, we mathematically model worm interactions based on major
worm interaction factors including worm interaction types, network
characteristics, and node characteristics using ordinary differential equations
and analyze their effects on our proposed metrics. We validate our proposed
model using extensive synthetic and trace-driven simulations. We find that, all
worm interaction factors significantly affect the pattern of worm propagations.
For example, immunization linearly decreases the infection of susceptible nodes
while on-off behavior only impacts the duration of infection. Using realistic
mobile network measurements, we find that encounters are bursty, multi-group
and non-uniform. The trends from the trace-driven simulations are consistent
with the model, in general. Immunization and timely deployment seem to be the
most effective to counter the worm attacks in such scenarios while cooperation
may help in a specific case. These findings provide insight that we hope would
aid to develop counter-worm protocols in future encounter-based networks.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:01:50 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Tanachaiwiwat",
"Sapon",
""
],
[
"Helmy",
"Ahmed",
""
]
] |
0706.4036 | Carol Jones | T. A. A. Sigut, C. E. Jones | The Thermal Structure of the Circumstellar Disk Surrounding the
Classical Be Star gamma Cassiopeia | 11 pages, 8 figures high resolution figures available at
http://inverse.astro.uwo.ca/sig_jon07.html | null | 10.1086/521209 | null | astro-ph | null | We have computed radiative equilibrium models for the gas in the
circumstellar envelope surrounding the hot, classical Be star $\gamma
$Cassiopeia. This calculation is performed using a code that incorporates a
number of improvements over previous treatments of the disk's thermal structure
by \citet{mil98} and \citet{jon04}; most importantly, heating and cooling rates
are computed with atomic models for H, He, CNO, Mg, Si, Ca, & Fe and their
relevant ions. Thus, for the first time, the thermal structure of a Be disk is
computed for a gas with a solar chemical composition as opposed to assuming a
pure hydrogen envelope. We compare the predicted average disk temperature, the
total energy loss in H$\alpha$, and the near-IR excess with observations and
find that all can be accounted for by a disk that is in vertical hydrostatic
equilibrium with a density in the equatorial plane of $\rho(R)\approx 3$ to
$5\cdot 10^{-11} (R/R_*)^{-2.5} \rm g cm^{-3}$. We also discuss the changes in
the disk's thermal structure that result from the additional heating and
cooling processes available to a gas with a solar chemical composition over
those available to a pure hydrogen plasma.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:18:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sigut",
"T. A. A.",
""
],
[
"Jones",
"C. E.",
""
]
] |
0706.4037 | Erik Muller | E. Muller, Q. Parker | Ha Emission from the Magellanic Bridge | 11 pages, 8 figures, 3 tables. Accepted for publication in PASA | Publ.Astron.Soc.Austral.24:69-76,2007 | 10.1071/AS07010 | null | astro-ph | null | We present here a preliminary report and commentary of recently processed
observations of Ha emission towards the Magellanic Bridge. These data have been
analysed in an attempt to quantify the extent to which the stellar population
is capable of reshaping the local ISM. We find that the Ha emission regions are
small, weak and sparsely distributed, consistent with a relatively quiescent
and inactive ISM where radiative and collisional ionisation is inefficient and
sporadic. This suggests that energetic processes at the small scale (i.e. ~tens
of pc) do not dominate the energy balance within the ISM of the Bridge, which
therefore hosts a pristine turbulent structure, otherwise inaccessible within
our own Galaxy. We find Ha emission that is well correlated with detected
12CO(1-0) line emission (a proxy for molecular hydrogen), as well as other
easily identified ring-like HI features.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:40:08 GMT"
}
] | 2010-05-17T00:00:00 | [
[
"Muller",
"E.",
""
],
[
"Parker",
"Q.",
""
]
] |
0706.4038 | Frederic Vivien | Matthieu Gallet (LIP, INRIA Rh\^one-Alpes), Yves Robert (LIP, INRIA
Rh\^one-Alpes), Fr\'ed\'eric Vivien (LIP, INRIA Rh\^one-Alpes) | Scheduling multiple divisible loads on a linear processor network | null | null | null | null | cs.DC | null | Min, Veeravalli, and Barlas have recently proposed strategies to minimize the
overall execution time of one or several divisible loads on a heterogeneous
linear network, using one or more installments. We show on a very simple
example that their approach does not always produce a solution and that, when
it does, the solution is often suboptimal. We also show how to find an optimal
schedule for any instance, once the number of installments per load is given.
Then, we formally state that any optimal schedule has an infinite number of
installments under a linear cost model as the one assumed in the original
papers. Therefore, such a cost model cannot be used to design practical
multi-installment strategies. Finally, through extensive simulations we
confirmed that the best solution is always produced by the linear programming
approach, while solutions of the original papers can be far away from the
optimal.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:43:13 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 15:02:05 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Gallet",
"Matthieu",
"",
"LIP, INRIA Rhône-Alpes"
],
[
"Robert",
"Yves",
"",
"LIP, INRIA\n Rhône-Alpes"
],
[
"Vivien",
"Frédéric",
"",
"LIP, INRIA Rhône-Alpes"
]
] |
0706.4039 | Raphael Lamon | Raphael Lamon, Nicolas Produit, Frank Steiner | Study of Lorentz violation in INTEGRAL Gamma-Ray Bursts | 14 pages, 4 figures | Gen.Rel.Grav.40:1731-1743,2008 | 10.1007/s10714-007-0580-6 | null | gr-qc astro-ph hep-th | null | We search for possible time lags caused by quantum gravitational (QG) effects
using gamma-ray bursts (GRBs) detected by INTEGRAL. The advantage of this
satellite is that we have at our disposal the energy and arrival time of every
detected single photon, which enhances the precision of the time resolution. We
present a new method for seeking time lags in unbinned data using a maximum
likelihood method and support our conclusions with Monte Carlo simulations. The
analysis of the data yields a mass scale well below the Planck mass whose value
may however increase if better statistics of GRBs were available. Furthermore,
we disagree with previous studies in which a non-monotonic function of the
redshift was used to perform a linear fit.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:55:24 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 09:01:27 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lamon",
"Raphael",
""
],
[
"Produit",
"Nicolas",
""
],
[
"Steiner",
"Frank",
""
]
] |
0706.4040 | George A. Levin | George A. Levin and Paul N. Barnes | Normal zone in $YBa_2Cu_3O_{6+x}$-coated conductors | 8 pages, 4 figures | null | 10.1088/0953-2048/20/12/003 | null | cond-mat.supr-con cond-mat.mtrl-sci | null | We consider the distribution of an electric field in YBCO-coated conductors
for a situation in which the DC transport current is forced into the copper
stabilizer due to a weak link -- a section of the superconducting film with a
critical current less than the transport current. The electric field in the
metal substrate is also discussed. The results are compared with recent
experiments on normal zone propagation in coated conductors for which the
substrate and stabilizer are insulated from each other. The potential
difference between the substrate and stabilizer, and the electric field in the
substrate outside the normal zone can be accounted for by a large screening
length in the substrate, comparable to the length of the sample. During a
quench, the electric field inside the interface between YBCO and stabilizer, as
well as in the buffer layer, can be several orders of magnitude greater than
the longitudinal macroscopic electric field inside the normal zone. We
speculate on the possibility of using possible microscopic electric discharges
caused by this large ($\sim $kV/cm) electric field as a means to detect a
quench.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:47:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Levin",
"George A.",
""
],
[
"Barnes",
"Paul N.",
""
]
] |
0706.4041 | Gyu-Boong Jo | G.-B. Jo, J.-H. Choi, C.A. Christensen, Y.-R. Lee, T.A. Pasquini, W.
Ketterle, and D.E. Pritchard | Matter-wave Interferometry with Phase Fluctuating Bose-Einstein
Condensates | 4 pages, 5 figures, figures corrected | Phys. Rev. Lett. 99, 240406 (2007) | 10.1103/PhysRevLett.99.240406 | null | cond-mat.other | null | Elongated Bose-Einstein condensates (BECs) exhibit strong spatial phase
fluctuations even well below the BEC transition temperature. We demonstrate
that atom interferometers using such condensates are robust against phase
fluctuations, i.e. the relative phase of the split condensate is reproducible
despite axial phase fluctuations. However, larger phase fluctuations limit the
coherence time, especially in the presence of some asymmetries in the two wells
of the interferometer.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:47:56 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 00:53:46 GMT"
},
{
"version": "v3",
"created": "Tue, 10 Jul 2007 13:51:58 GMT"
}
] | 2007-12-16T00:00:00 | [
[
"Jo",
"G. -B.",
""
],
[
"Choi",
"J. -H.",
""
],
[
"Christensen",
"C. A.",
""
],
[
"Lee",
"Y. -R.",
""
],
[
"Pasquini",
"T. A.",
""
],
[
"Ketterle",
"W.",
""
],
[
"Pritchard",
"D. E.",
""
]
] |
0706.4042 | Emmanuel Gobet | Emmanuel Gobet (LJK), St\'ephane Menozzi (PMA) | Stopped diffusion processes: boundary corrections and overshoot | 39 pages | Stochastic Processes and their Applications 120 (2010) 130-162 | null | null | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For a stopped diffusion process in a multidimensional time-dependent domain
$\D$, we propose and analyse a new procedure consisting in simulating the
process with an Euler scheme with step size $\Delta$ and stopping it at
discrete times $(i\Delta)_{i\in\N^*}$ in a modified domain, whose boundary has
been appropriately shifted. The shift is locally in the direction of the inward
normal $n(t,x)$ at any point $(t,x)$ on the parabolic boundary of $\D$, and its
amplitude is equal to $0.5826 (...) |n^*\sigma|(t,x)\sqrt \Delta$ where
$\sigma$ stands for the diffusion coefficient of the process. The procedure is
thus extremely easy to use. In addition, we prove that the rate of convergence
w.r.t. $\Delta$ for the associated weak error is higher than without shifting,
generalizin g previous results by \cite{broa:glas:kou:97} obtained for the one
dimensional Brownian motion. For this, we establish in full generality the
asymptotics of the triplet exit time/exit position/overshoot for the discretely
stopped Euler scheme. Here, the overshoot means the distance to the boundary of
the process when it exits the domain. Numerical experiments support these
results.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:49:03 GMT"
},
{
"version": "v2",
"created": "Thu, 18 Jun 2009 11:35:16 GMT"
}
] | 2010-04-22T00:00:00 | [
[
"Gobet",
"Emmanuel",
"",
"LJK"
],
[
"Menozzi",
"Stéphane",
"",
"PMA"
]
] |
0706.4043 | Mark D. Roberts | Mark D. Roberts | Frame Dependence in Scalar-tensor Theory | 12 pages | null | null | null | gr-qc | null | Palatini variation of Jordan frame lagrangians gives an equation relating the
dilaton to the object of non-metricity and hence the existence of the dilaton
implies that the spacetime connection is more general than that given soley by
the Christoffel symbol of general relativity. Transferring from Jordan to
Einstein frame, which connection, lagrangian, field equations and stress
conservation equations occur are discussed: it is found that the Jordan frame
has more information, this can be expressed in several ways, the simplest is
that the extra information corresponds to the function multiplying the Ricci
scalar in the action. The Einstein frame has the advantages that stress
conservation implies no currents and that the field equations are easier to
work with. This is illustrated by application to Robertson-Walker spacetime.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:59:44 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Roberts",
"Mark D.",
""
]
] |
0706.4044 | Lutz Schr\"oder | Lutz Schr\"oder and Dirk Pattinson | PSPACE Bounds for Rank-1 Modal Logics | null | ACM Transactions on Computational Logic 10 (2:13), pp. 1-33, 2009 | 10.1145/1462179.1462185 | Imperial College TR 2007/4 | cs.LO cs.CC | null | For lack of general algorithmic methods that apply to wide classes of logics,
establishing a complexity bound for a given modal logic is often a laborious
task. The present work is a step towards a general theory of the complexity of
modal logics. Our main result is that all rank-1 logics enjoy a shallow model
property and thus are, under mild assumptions on the format of their
axiomatisation, in PSPACE. This leads to a unified derivation of tight
PSPACE-bounds for a number of logics including K, KD, coalition logic, graded
modal logic, majority logic, and probabilistic modal logic. Our generic
algorithm moreover finds tableau proofs that witness pleasant proof-theoretic
properties including a weak subformula property. This generality is made
possible by a coalgebraic semantics, which conveniently abstracts from the
details of a given model class and thus allows covering a broad range of logics
in a uniform way.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:15:57 GMT"
}
] | 2011-01-18T00:00:00 | [
[
"Schröder",
"Lutz",
""
],
[
"Pattinson",
"Dirk",
""
]
] |
0706.4045 | Vicentiu Radulescu | Mihai Mihailescu (UCV), Vicentiu Radulescu (IMAR) | Continuous spectrum for a class of nonhomogeneous differential operators | null | null | null | null | math.AP | null | We study the boundary value problem $-{\rm div}((|\nabla
u|^{p_1(x)-2}+|\nabla u|^{p_2(x)-2})\nabla u)=\lambda|u|^{q(x)-2}u$ in
$\Omega$, $u=0$ on $\partial\Omega$, where $\Omega$ is a bounded domain in
$\RR^N$ with smooth boundary, $\lambda$ is a positive real number, and the
continuous functions $p_1$, $p_2$, and $q$ satisfy $1<p_2(x)<q(x)<p_1(x)<N$ and
$\max_{y\in\bar\Omega}q(y)<\frac{N p_2(x)}{N-p_2(x)}$ for any $x\in\bar\Omega$.
The main result of this paper establishes the existence of two positive
constants $\lambda_0$ and $\lambda_1$ with $\lambda_0\leq\lambda_1$ such that
any $\lambda\in[\lambda_1,\infty)$ is an eigenvalue, while any
$\lambda\in(0,\lambda_0)$ is not an eigenvalue of the above problem.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:13:52 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Mihailescu",
"Mihai",
"",
"UCV"
],
[
"Radulescu",
"Vicentiu",
"",
"IMAR"
]
] |
0706.4046 | Kai Cai | Kai Cai, Richard H. Durisen, Aaron C. Boley, Megan K. Pickett, Annie
C. Mejia | The Thermal Regulation of Gravitational Instabilities in Protoplanetary
Disks. IV. Simulations with Envelope Irradiation | ApJ, in press (tentatively scheduled for Jan. 2008, v.673) | null | 10.1086/524101 | null | astro-ph | null | It is generally thought that protoplanetary disks embedded in envelopes are
more massive and thus more susceptible to gravitational instabilities (GIs)
than exposed disks. We present three-dimensional radiative hydrodynamics
simulations of protoplanetary disks with the presence of envelope irradiation.
For a disk with a radius of 40 AU and a mass of 0.07 Msun around a young star
of 0.5 Msun, envelope irradiation tends to weaken and even suppress GIs as the
irradiating flux is increased. The global mass transport induced by GIs is
dominated by lower-order modes, and irradiation preferentially suppresses
higher-order modes. As a result, gravitational torques and mass inflow rates
are actually increased by mild irradiation. None of the simulations produce
dense clumps or rapid cooling by convection, arguing against direct formation
of giant planets by disk instability, at least in irradiated disks. However,
dense gas rings and radial mass concentrations are produced, and these might be
conducive to accelerated planetary core formation. Preliminary results from a
simulation of a massive embedded disk with physical characteristics similar to
one of the disks in the embedded source L1551 IRS5 indicate a long radiative
cooling time and no fragmentation. The GIs in this disk are dominated by global
two and three-armed modes.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:58:34 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 20:00:07 GMT"
},
{
"version": "v3",
"created": "Wed, 17 Oct 2007 19:53:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cai",
"Kai",
""
],
[
"Durisen",
"Richard H.",
""
],
[
"Boley",
"Aaron C.",
""
],
[
"Pickett",
"Megan K.",
""
],
[
"Mejia",
"Annie C.",
""
]
] |
0706.4047 | Jean-Luc Garden | Jean-Luc Garden (NEEL) | Simple derivation of the frequency dependent complex heat capacity | null | Thermochimica Acta 460 (25/08/2007) 85-87 | 10.1016/j.tca.2007.05.010 | null | cond-mat.other | null | This paper gives a simple derivation of the well-known expression of the
frequency dependent complex heat capacity in modulated temperature experiments.
It aims at clarified again that the generalized calorimetric susceptibility is
only due to the non-equilibrium behaviour occurring in the vicinity of
thermodynamic equilibrium of slow internal degrees of freedom of a sample when
the temperature oscillates at a well determined frequency.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:20:35 GMT"
}
] | 2007-07-15T00:00:00 | [
[
"Garden",
"Jean-Luc",
"",
"NEEL"
]
] |
0706.4048 | Michael Noble S. | Michael S. Noble | Getting More From Your Multicore: Exploiting OpenMP From An Open Source
Numerical Scripting Language | 15 pages, 16 figures; working paper, in preparation | null | null | null | cs.DC astro-ph | null | We introduce SLIRP, a module generator for the S-Lang numerical scripting
language, with a focus on its vectorization capabilities. We demonstrate how
both SLIRP and S-Lang were easily adapted to exploit the inherent parallelism
of high-level mathematical languages with OpenMP, allowing general users to
employ tightly-coupled multiprocessors in scriptable research calculations
while requiring no special knowledge of parallel programming. Motivated by
examples in the ISIS astrophysical modeling & analysis tool, performance
figures are presented for several machine and compiler configurations,
demonstrating beneficial speedups for real-world operations.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:21:28 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Noble",
"Michael S.",
""
]
] |
0706.4049 | Wojciech Dybalski | Wojciech Dybalski | A sharpened nuclearity condition and the uniqueness of the vacuum in QFT | 20 pages, LaTeX. As appeared in Communications in Mathematical
Physics | Commun.Math.Phys.283:523-542,2008 | 10.1007/s00220-008-0514-5 | null | math-ph hep-th math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is shown that only one vacuum state can be prepared with a finite amount
of energy and it appears, in particular, as a limit of physical states under
large timelike translations in any theory which satisfies a phase space
condition proposed in this work. This new criterion, related to the concept of
additivity of energy over isolated subsystems, is verified in massive free
field theory. The analysis entails very detailed results about the momentum
transfer of local operators in this model.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:23:44 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 18:36:42 GMT"
},
{
"version": "v3",
"created": "Mon, 7 Jul 2008 20:33:41 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dybalski",
"Wojciech",
""
]
] |
0706.4050 | Jean-Luc Garden | Jean-Luc Garden (NEEL), Jacques Richard (NEEL), H. Guillou (NEEL), O.
Bourgeois (NEEL) | Non-equilibrium heat capacity of polytetrafluoroethylene at room
temperature | null | null | null | null | cond-mat.soft | null | Polytetrafluoroethylene can be considered as a model for calorimetric studies
of complex systems with thermodynamics transitions at ambient temperature. This
polymer exhibits two phase transitions of different nature at 292 K and 303 K.
We show that sensitive ac-calorimetry measurements allow us to study the
thermodynamic behaviour of polytetrafluoroethylene when it is brought out of
thermodynamic equilibrium. Thanks to the thermal modelisation of our
calorimetric device, the frequency dependent complex heat capacity of this
polymer is extracted. The temperature and frequency variations of the real and
imaginary parts of the complex heat capacity are obtained when
polytetrafluoroethylene undergoes its first-order structural phase transition
at 292 K.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:24:09 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Garden",
"Jean-Luc",
"",
"NEEL"
],
[
"Richard",
"Jacques",
"",
"NEEL"
],
[
"Guillou",
"H.",
"",
"NEEL"
],
[
"Bourgeois",
"O.",
"",
"NEEL"
]
] |
0706.4051 | Andrei Dubin | A. Yu. Dubin | A novel renormalizable representation of the Yang-Mills theory | 13 pages, no figures | null | null | null | hep-th | null | For a generic gauge-invariant correlator <{\cal Q}[A_{\mu}]>_{A}, we
reformulate the standard D=4 Yang-Mills theory as a renormalizable system of
two interacting fields a_{\mu} and B_{\mu} which faithfully represent high- and
low-energy degrees of freedom of the single gauge field A_{\mu} in the original
formulation. It opens a possibility to synthesize an infrared-nonsingular
weak-coupling series, employed to integrate over a_{\mu} for a given background
B_{\mu}, with qualitatively different methods. These methods are to be applied
to evaluate the resulting (after the a_{\mu}-integration) representation of
<{\cal Q}[A_{\mu}]>_{A} in terms of gauge-invariant generically non-local
low-energy observables, like Wilson loops. The latter observables are averaged
over B_{\mu} with respect to a gauge-invariant Wilsonean effective action
S_{eff}[B]. To avoid a destructive dissipation between the high- and low-energy
excitations, we implement a specific fine-tuning of the interaction between the
pair of the fields: prior to the integration over B_{\mu}, the expectation
value <a_{\mu}>_{a} vanishes, in the tree order of the loop-wise expansion, for
an arbitrary configuration of B_{\mu}.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:24:11 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Dubin",
"A. Yu.",
""
]
] |
0706.4052 | C. P. Martin | C.P. Martin and C. Tamarit (Universidad Complutense de Madrid) | Renormalisability of the matter determinants in noncommutative gauge
theory in the enveloping-algebra formalism | 7 pages | Phys.Lett.B658:170-173,2008 | 10.1016/j.physletb.2007.08.033 | FTI/UCM 75-2007 | hep-th | null | We consider noncommutative gauge theory defined by means of Seiberg-Witten
maps for an arbitrary semisimple gauge group. We compute the one-loop UV
divergent matter contributions to the gauge field effective action to all
orders in the noncommutative parameters $\theta$. We do this for Dirac fermions
and complex scalars carrying arbitrary representations of the gauge group. We
use path-integral methods in the framework of dimensional regularisation and
consider arbitrary invertible Seiberg-Witten maps that are linear in the matter
fields. Surprisingly, it turns out that the UV divergent parts of the matter
contributions are proportional to the noncommutative Yang-Mills action where
traces are taken over the representation of the matter fields; this result
supports the need to include such traces in the classical action of the gauge
sector of the noncommutative theory.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:35:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Martin",
"C. P.",
"",
"Universidad Complutense de Madrid"
],
[
"Tamarit",
"C.",
"",
"Universidad Complutense de Madrid"
]
] |
0706.4053 | Alejandro Kocsard | Alejandro Kocsard | Toward the classification of cohomology-free vector fields | 70 pages, PhD thesis (IMPA, May 2007). Corrected typos | null | null | null | math.DS math.GT | null | In 1984, Anatole Katok conjectured that the only closed orientable manifolds
that support cohomology-free vector fields are tori and these vector fields are
smoothly conjugated to Diophantine (constant) ones.
In this work we present a proof of Katok conjecture for 3-manifolds.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:37:38 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Jul 2007 23:08:26 GMT"
}
] | 2007-07-12T00:00:00 | [
[
"Kocsard",
"Alejandro",
""
]
] |
0706.4054 | Alexander Goncharov | A.B. Goncharov | The pentagon relation for the quantum dilogarithm and quantized M_{0,5} | 12 pages. To appear in the Progress in Mathematics volume
(Birkhauser) dedicated to the memory of Alexander Reznikov. The second
version is hopefully the final one. It clarifies, corrects and expands the
first one | null | null | null | math.QA math.FA | null | We introduce and study a Schwarz space S in the space of functions on the
real line. It is a module over the algebra L of regular functions on the
(modular double of the) non-commutative q-deformation of the moduli space of
configurations of 5 cyclically ordered points on the projective line. The
algebra L has an order five automorphism corresponding to the cyclic shift of
the points. The quantum dilogarithm gives rise to an automorphism of the space
Schwarz S intertwining the automorphism of L. This easily implies the pentagon
relation for the quantum dilogarithm function.
The triple (L, S, the automorphism) is the quantized moduli space of
configurations of 5 points on the projective line. It is the simplest example
of a quantized cluster X-variety.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:38:01 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 08:40:00 GMT"
}
] | 2007-07-25T00:00:00 | [
[
"Goncharov",
"A. B.",
""
]
] |
0706.4055 | Carlos Kenig | J.Colliander, A.D.Ionescu, C.E.Kenig and G.Staffilani | Weighted Low-Regularity Solutions of the KP-I Initial Value Problem | null | null | null | null | math.AP | null | In this paper we establish local well-posedness of the KP-I problem, with
initial data small in the intersection of the natural energy space with the
space of functions which are square integrable when multiplied by the weight y.
The result is proved by the contraction mapping principle. A similar (but
slightly weaker) result was the main Theorem in the paper " Low regularity
solutions for the Kadomstev-Petviashvili I equation " by Colliander, Kenig and
Staffilani (GAFA 13 (2003),737-794 and math.AP/0204244). Ionescu found a
counterexample (included in the present paper) to the main estimate used in the
GAFA paper, which renders incorrect the proof there. The present paper thus
provides a correct proof of a strengthened version of the main result in the
GAFA paper.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:48:38 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Colliander",
"J.",
""
],
[
"Ionescu",
"A. D.",
""
],
[
"Kenig",
"C. E.",
""
],
[
"Staffilani",
"G.",
""
]
] |
0706.4056 | Miron Amusia | M. Ya. Amusia (1, 2), A. S. Baltenkov (3) and L. V. Chernysheva (2)
((1)Hebrew University, Jerusalem, Israel; (2) Ioffe Physical-Technical
Institute, St.-Petersburg, Russia (3) Arifov Institute of Electronics,
Tashkent, Uzbekistan) | Photoionization of 3d electrons of Xe, Cs and Ba endohedral atoms:
comparative analyses | 26 pages, 15 figures | null | 10.2478/s11534-008-0004-6 | null | physics.atom-ph physics.atm-clus | null | We demonstrate rather interesting manifestations of co-existence of resonance
features in characteristics of the photoionization of 3d-electrons in Xe, Cs
and Ba endohedral atoms. It is shown that for all of the considered atoms the
reflection by the fullerene shell of photoelectrons produced by the 3d subshell
photoionization affects greatly partial photoionization cross-sections of 3d5/2
and 3d3/2 levels and respective angular anisotropy parameters, both dipole and
non-dipole adding to all of them additional maximums and minimums. The results
obtained demonstrate distinctive differences between the three atoms.
The calculations are performed treating the 3/2 and 5/2 electrons as
electrons of different kinds with their spins "up" and "down". The effect of
C60 shell is accounted for in the frame of the "orange" skin potential model.
It is essential that in the considered photon frequency region presented
resonance features are not affected by the C60 polarization.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:48:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Amusia",
"M. Ya.",
""
],
[
"Baltenkov",
"A. S.",
""
],
[
"Chernysheva",
"L. V.",
""
]
] |
0706.4057 | Piotr T. Chru\'sciel | Piotr T. Chru\'sciel and Paul Tod | An angular momentum bound at null infinity | null | null | null | null | gr-qc | null | We prove an inequality relating the trace of the extrinsic curvature, the
total angular momentum, the centre of mass, and the Trautman-Bondi mass for a
class of gravitational initial data sets with constant mean curvature extending
to null infinity. As an application we obtain non-existence results for the
asymptotic Dirichlet problem for CMC hypersurfaces in stationary space-times.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:49:39 GMT"
}
] | 2016-09-08T00:00:00 | [
[
"Chruściel",
"Piotr T.",
""
],
[
"Tod",
"Paul",
""
]
] |
0706.4058 | Stefan Thurner | Peter Klimek, Renaud Lambiotte, Stefan Thurner | Opinion Formation in Laggard Societies | 5 pages, eps figs | null | 10.1209/0295-5075/82/28008 | null | physics.soc-ph | null | We introduce a statistical physics model for opinion dynamics on random
networks where agents adopt the opinion held by the majority of their direct
neighbors only if the fraction of these neighbors exceeds a certain threshold,
p_u. We find a transition from total final consensus to a mixed phase where
opinions coexist amongst the agents. The relevant parameters are the relative
sizes in the initial opinion distribution within the population and the
connectivity of the underlying network. As the order parameter we define the
asymptotic state of opinions. In the phase diagram we find regions of total
consensus and a mixed phase. As the 'laggard parameter' p_u increases the
regions of consensus shrink. In addition we introduce rewiring of the
underlying network during the opinion formation process and discuss the
resulting consequences in the phase diagram.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:55:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Klimek",
"Peter",
""
],
[
"Lambiotte",
"Renaud",
""
],
[
"Thurner",
"Stefan",
""
]
] |
0706.4059 | Evgueni Goudzovski | Evgueni Goudzovski | Precision study of K^\pm\to\pi^\pm\pi^0\pi^0 and
K^\pm\to\pi^\pm\pi^+\pi^- Dalitz plot distributions by NA48/2 | Talk given at Kaon'07 Conference, LNF, Frascati, Italy, 21--25 May,
2007. A version revised by PoS referee | PoSKAON:034,2008 | null | null | hep-ex | null | The NA48/2 experiment at the CERN SPS has collected an unprecedented sample
of $K^\pm\to3\pi$ decays. The high statistics and the good resolution of the
detectors allow a unique investigation of the detailed phase space
distributions of these decays. The effects of final state pion rescattering
observed in the Dalitz plot distribution of the $K^\pm\to\pi^\pm\pi^0\pi^0$
decays turned out to be a powerful tool for extraction of the S-wave $\pi\pi$
scattering lengths. The large statistics also allowed a precise measurement of
the Dalitz plot slope parameters for the $K^\pm\to3\pi^\pm$ decays.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 15:57:56 GMT"
},
{
"version": "v2",
"created": "Sun, 29 Jul 2007 17:08:01 GMT"
},
{
"version": "v3",
"created": "Sun, 16 Sep 2007 20:49:28 GMT"
}
] | 2009-04-16T00:00:00 | [
[
"Goudzovski",
"Evgueni",
""
]
] |
0706.4060 | Manuel Blickle | Manuel Blickle | Minimal $\gamma$--sheaves | 17 pages | Algebra Number Theory 2 (2008), no. 3, 347-368 | null | null | math.AG math.AC | null | In this note we show that finitely generated unit $O_X[\sigma]$--modules for
$X$ regular and $F$--finite have a minimal root (in the sense of [Lyubeznik,
F-modules] Definition~3.6). This problem was posed by Lyubeznik and answered by
himself in the case that $X=\Spec R$ is a complete local ring.
One immediate consequence of this result is that the parameter test module of
tight closure theory commutes with localization. As a further application of
the methods in this paper we give new proofs of the results on discreteness and
rationality of $F$--thresholds [arXiv:0705.1210] and on $D$-module generation
[arXiv:math/0502405v1]. The new proofs are valid in a slightly more general
setting such that they also party cover the generalizations recently obtained
in [arXiv:0706.3028].
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:01:36 GMT"
}
] | 2011-02-18T00:00:00 | [
[
"Blickle",
"Manuel",
""
]
] |
0706.4061 | Georges Comte | Georges Comte, Michel Merle | Equisingularite reelle : invariants locaux et conditions de regularite | 49 pages, 1 figure | Ann. Sci. \'Ecole Norm. Sup., s\'erie 4, 41, fascicule 2 (2008),
221-269 | null | null | math.DG math.MG | null | For germs of subanalytic sets, we define two finite sequences of new
numerical invariants. The first one is obtained by localizing the classical
Lipschitz-Killing curvatures, the second one is the real analogue of the
evanescent characteristics introduced by M. Kashiwara. We show that each
invariant of one sequence is a linear combination of the invariants of the
other sequence. We then connect our invariants to the geometry of the
discriminants of all dimension. Finally we prove that these invariants are
continuous along Verdier strata of a closed subanalytic set.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:09:52 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Sep 2007 12:31:31 GMT"
},
{
"version": "v3",
"created": "Tue, 30 Oct 2007 19:12:42 GMT"
}
] | 2011-11-15T00:00:00 | [
[
"Comte",
"Georges",
""
],
[
"Merle",
"Michel",
""
]
] |
0706.4062 | Felix Delgado | A. Campillo, F. Delgado, S.M. Gusein-Zade | Universal abelian covers of rational surface singularities and
multi-index filtrations | null | null | null | null | math.AG | null | In previous papers, there were computed the Poincare series of some
(multi-index) filtrations on the ring of germs of functions on a rational
surface singularity. These Poincare series were written as the integer parts of
certain fractional power series, an interpretation of whom was not given. Here
we show that, up to a simple change of variables, these fractional power series
are specializations of the equivariant Poincare series for filtrations on the
ring of germs of functions on the universal abelian cover of the surface
singularity. We compute these equivariant Poincare series.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:14:38 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Campillo",
"A.",
""
],
[
"Delgado",
"F.",
""
],
[
"Gusein-Zade",
"S. M.",
""
]
] |
0706.4063 | Zoltan Nagy | Zoltan Nagy | QCD and Monte Carlo generators | Plenary talk at 15th International Workshop on Deep Inelastic
Scattering and Related Subjects (DIS 2007), Munich, Germany, 16-20 Apr 2007.
12 pages, 9 figures; added references | null | null | null | hep-ph | null | In this talk I gave a brief summary of leading order, next-to-leading order
and shower calculations. I discussed the main ideas and approximations of the
shower algorithms and the related matching schemes. I tried to focus on QCD
issues and open questions instead of making a inventory of the existing
programs.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:18:13 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 08:54:29 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Nagy",
"Zoltan",
""
]
] |
0706.4064 | Andrei Smilga | A.V. Smilga | Cryptogauge symmetry and cryptoghosts for crypto-Hermitian Hamiltonians | 24 pages, 12 figures. Final version to be published in J.Phys. A | J.Phys.A41:244026,2008 | 10.1088/1751-8113/41/24/244026 | null | quant-ph hep-th math-ph math.MP | null | We discuss the Hamiltonian H = p^2/2 - (ix)^{2n+1} and the mixed Hamiltonian
H = (p^2 + x^2)/2 - g(ix)^{2n+1}, which are crypto-Hermitian in a sense that,
in spite of apparent complexity of the potential, a quantum spectral problem
can be formulated such that the spectrum is real. We note first that the
corresponding classical Hamiltonian system can be treated as a gauge system,
with imaginary part of the Hamiltonian playing the role of the first class
constraint. We observe then that, on the basis of this classical problem,
several different nontrivial quantum problems can be formulated. We formulate
and solve some such problems. We find in particular that the spectrum of the
mixed Hamiltonian undergoes in certain cases rather amazing transformation when
the coupling g is sent to zero. There is an infinite set of phase transitions
in g when a couple of eigenstates of H coalesce and disappear from the
spectrum. When quantization is done in the most natural way such that gauge
constraints are imposed on quantum states, the spectrum should not be positive
definite, but must involve the negative energy states (ghosts). We speculate
that, in spite of the appearance of ghost states, unitarity might still be
preserved.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:34:50 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 13:56:13 GMT"
},
{
"version": "v3",
"created": "Tue, 20 Nov 2007 16:10:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Smilga",
"A. V.",
""
]
] |
0706.4065 | Vincenzo Vitale | J. Albert, et al (for the MAGIC collaboration) | Observation of VHE gamma-rays from Cassiopeia A with the MAGIC telescope | 4 pages, 4 figures, submitted to A&A | Astron.Astrophys.474:937-940,2007 | 10.1051/0004-6361:20078168 | null | astro-ph | null | We searched for very high energy (VHE) gamma-ray emission from the supernova
remnant Cassiopeia A. The shell-type supernova remnant Cassiopeia A was
observed with the 17 meter MAGIC telescope between July 2006 and January 2007
for a total time of 47 hours. The source was detected above an energy of 250
GeV with a significance of 5.2sigma and a photon flux above 1 TeV of
(7.3+-0.7_stat+-2.2_sys)10^-13 cm^-2s^-1. The photon spectrum is compatible
with a power law dN/dE = A E^-Gamma with a photon index
Gamma=2.3+-0.2_stat+-0.2_sys. The source is point-like within the angular
resolution of the telescope.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:28:31 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Dec 2007 16:11:27 GMT"
}
] | 2019-08-12T00:00:00 | [
[
"Albert",
"J.",
""
]
] |
0706.4066 | Yuri Sinyukov | Yu.M. Sinyukov, S.V. Akkelin, Iu.A. Karpenko | Pion spectra and HBT radii at RHIC and LHC | 2 pages, 4 figures. Contributed to the Workshop on Heavy Ion
Collisions at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May
- 8 Jun 2007 | null | null | null | nucl-th | null | We describe RHIC pion data in central A+A collisions and make predictions for
LHC based on hydro-kinetic model, describing continuous 4D particle emission,
and initial conditions taken from Color Glass Condensate (CGC) model.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:28:34 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Sinyukov",
"Yu. M.",
""
],
[
"Akkelin",
"S. V.",
""
],
[
"Karpenko",
"Iu. A.",
""
]
] |
0706.4067 | Indranil Chakrabarty ic | Indranil Chakrabarty | Partial Swapping, Unitarity and No-signalling | 7 pages, no figures | EJTP 6, No. 21 119--124 (2009) | null | null | quant-ph | null | It is a well known fact that an quantum state $|\psi(\theta,\phi)>$ is
represented by a point on the Bloch sphere, characterized by two parameters
$\theta$ and $\phi$. In a recent work we already proved that it is impossible
to partially swap these quantum parameters. Here in this work we will show that
this impossibility theorem is consistent with principles like unitarity of
quantum mechanics and no signalling principle.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:31:17 GMT"
}
] | 2009-05-06T00:00:00 | [
[
"Chakrabarty",
"Indranil",
""
]
] |
0706.4068 | Arthur Chernin | A.D. Chernin, I.D. Karachentsev, P. Teerikorpi, M.J. Valtonen, G.G.
Byrd, Yu.N. Efremov, V.P. Dolgachev, L.M. Domozhilova, D.I. Makarov, Yu.V.
Baryshev | Detection of dark energy near the Local Group with the Hubble Space
Telescope | 11 pages, 1 figure | Grav.Cosmol.16:1-6,2010 | 10.1134/S0202289310010019 | null | astro-ph | null | We report the detection of dark energy near the Milky Way made with precision
observations of the local Hubble flow of expansion. We estimate the local
density of dark energy and find that it is near, if not exactly equal to, the
global dark energy density. The result is independent of, compatible with, and
complementary to the horizon-scale observations in which dark energy was first
discovered. Together with the cosmological concordance data, our result forms
direct observational evidence for the Einstein antigravity as a universal
phenomenon -- in the same sense as the Newtonian universal gravity.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:44:31 GMT"
}
] | 2010-03-19T00:00:00 | [
[
"Chernin",
"A. D.",
""
],
[
"Karachentsev",
"I. D.",
""
],
[
"Teerikorpi",
"P.",
""
],
[
"Valtonen",
"M. J.",
""
],
[
"Byrd",
"G. G.",
""
],
[
"Efremov",
"Yu. N.",
""
],
[
"Dolgachev",
"V. P.",
""
],
[
"Domozhilova",
"L. M.",
""
],
[
"Makarov",
"D. I.",
""
],
[
"Baryshev",
"Yu. V.",
""
]
] |
0706.4069 | Laurent Goergen | Laurent Goergen | An effective criterion and a new example for ballistic diffusions in
random environment | Published in at http://dx.doi.org/10.1214/07-AOP354 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org) | Annals of Probability 2008, Vol. 36, No. 3, 1093-1133 | 10.1214/07-AOP354 | IMS-AOP-AOP354 | math.PR | null | In the setting of multidimensional diffusions in random environment, we carry
on the investigation of condition $(T')$, introduced by Sznitman [Ann. Probab.
29 (2001) 723--764] and by Schmitz [Ann. Inst. H. Poincar\'{e} Probab. Statist.
42 (2006) 683--714] respectively in the discrete and continuous setting, and
which implies a law of large numbers with nonvanishing limiting velocity
(ballistic behavior) as well as a central limit theorem. Specifically, we show
that when $d\geq2$, $(T')$ is equivalent to an effective condition that can be
checked by local inspection of the environment. When $d=1$, we prove that
condition $(T')$ is merely equivalent to almost sure transience. As an
application of the effective criterion, we show that when $d\geq4$ a
perturbation of Brownian motion by a random drift of size at most $\epsilon>0$
whose projection on some direction has expectation bigger than
$\epsilon^{2-\eta},\eta>0$, satisfies condition $(T')$ when $\epsilon$ is small
and hence exhibits ballistic behavior. This class of diffusions contains new
examples of ballistic behavior which in particular do not fulfill the condition
in [Ann. Inst. H. Poincar\'{e} Probab. Statist. 42 (2006) 683--714], (5.4)
therein, related to Kalikow's condition.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:45:41 GMT"
},
{
"version": "v2",
"created": "Mon, 16 Jun 2008 05:45:08 GMT"
}
] | 2008-06-16T00:00:00 | [
[
"Goergen",
"Laurent",
""
]
] |
0706.4070 | Daniel Grumiller | M. Adak and D. Grumiller | Poisson-sigma model for 2D gravity with non-metricity | 9 pages | Class.Quant.Grav.24:F65-F72,2007 | 10.1088/0264-9381/24/20/F01 | MIT-CTP 3842 | hep-th gr-qc math-ph math.MP | null | We present a Poisson-sigma model describing general 2D dilaton gravity with
non-metricity, torsion and curvature. It involves three arbitrary functions of
the dilaton field, two of which are well-known from metric compatible theories,
while the third one characterizes the local strength of non-metricity. As an
example we show that alpha' corrections in 2D string theory can generate
(target space) non-metricity.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:34:01 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 20:42:38 GMT"
}
] | 2010-11-02T00:00:00 | [
[
"Adak",
"M.",
""
],
[
"Grumiller",
"D.",
""
]
] |
0706.4071 | Alessandro Strumia | Marco Cirelli, Alessandro Strumia, Matteo Tamburini | Cosmology and Astrophysics of Minimal Dark Matter | 24 pages, 10 figures; v2: typos corrected, to appear on NPB | Nucl.Phys.B787:152-175,2007 | 10.1016/j.nuclphysb.2007.07.023 | IFUP-TH/2007-12, SACLAY-T07/052 | hep-ph astro-ph | null | We consider DM that only couples to SM gauge bosons and fills one gauge
multiplet, e.g. a fermion 5-plet (which is automatically stable), or a
wino-like 3-plet. We revisit the computation of the cosmological relic
abundance including non-perturbative corrections. The predicted mass of e.g.
the 5-plet increases from 4.4 TeV to 10 TeV, and indirect detection rates are
enhanced by 2 orders of magnitude. Next, we show that due to the
quasi-degeneracy among neutral and charged components of the DM multiplet, a
significant fraction of DM with energy E > 10^17 eV (possibly present among
ultra-high energy cosmic rays) can cross the Earth exiting in the charged state
and may in principle be detected in neutrino telescopes.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:06:15 GMT"
},
{
"version": "v2",
"created": "Thu, 26 Jul 2007 07:22:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cirelli",
"Marco",
""
],
[
"Strumia",
"Alessandro",
""
],
[
"Tamburini",
"Matteo",
""
]
] |
0706.4072 | James Lepowsky | James Lepowsky | Some developments in vertex operator algebra theory, old and new | 41 pages. To appear in proceedings of conference on Lie Algebras,
Vertex Operator Algebras and Their Applications, North Carolina State
University, 2005, Contemporary Math | null | null | null | math.QA hep-th math-ph math.MP math.RT | null | In this exposition, I discuss several developments in the theory of vertex
operator algebras, and I include motivation for the definition.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:27:41 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Lepowsky",
"James",
""
]
] |
0706.4073 | Marko Robnik | S. Grossmann and M. Robnik | Some generic properties of level spacing distributions of 2D real random
matrices | 21 pages, no figures, submitted to Zeitschrift fuer Naturforschung A | null | 10.1515/zna-2007-0902 | CAMTP Preprint 5 April 2007 | nlin.CD | null | We study the level spacing distribution $P(S)$ of 2D real random matrices
both symmetric as well as general, non-symmetric. In the general case we
restrict ourselves to Gaussian distributed matrix elements, but different
widths of the various matrix elements are admitted. The following results are
obtained: An explicit exact formula for $P(S)$ is derived and its behaviour
close to S=0 is studied analytically, showing that there is linear level
repulsion, unless there are additional constraints for the probability
distribution of the matrix elements. The constraint of having only positive or
only negative but otherwise arbitrary non-diagonal elements leads to quadratic
level repulsion with logarithmic corrections. These findings detail and extend
our previous results already published in a preceding paper. For the {\em
symmetric} real 2D matrices also other, non-Gaussian statistical distributions
are considered. In this case we show for arbitrary statistical distribution of
the diagonal and non-diagonal elements that the level repulsion exponent $\rho$
is always $\rho = 1$, provided the distribution function of the matrix elements
is regular at zero value. If the distribution function of the matrix elements
is a singular (but still integrable) power law near zero value of $S$, the
level spacing distribution $P(S)$ is a fractional exponent pawer law at small
$S$. The tail of $P(S)$ depends on further details of the matrix element
statistics. We explicitly work out four cases: the constant (box) distribution,
the Cauchy-Lorentz distribution, the exponential distribution and, as an
example for a singular distribution, the power law distribution for $P(S)$ near
zero value times an exponential tail.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 17:03:36 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Grossmann",
"S.",
""
],
[
"Robnik",
"M.",
""
]
] |
0706.4074 | Elliott Cheu | KTeV Collaboration: E. Abouzaid, M. Arenton, A.R. Barker, L.
Bellantoni, E. Blucher, G.J. Bock, E. Cheu, R. Coleman, B. Cox, A.R. Erwin,
C.O. Escobar, A. Glazov, A. Golossanov, R.A. Gomes, P. Gouffon, Y.B. Hsiung,
D.A. Jensen, R. Kessler, Y.J. Kim, K. Kotera, A. Ledovskoy, P.L. McBride, E.
Monnier, K.S. Nelson, H. Nguyen, R. Niclasen, D.G. Phillips II, H. Ping, E.J.
Ramberg, R.E. Ray, M. Ronquest, E. Santos, W. Slater, D. Smith, N. Solomey,
E.C. Swallow, P.A. Toale, R. Tschirhart, C. Velissaris, Y.W. Wah, J. Wang,
H.B. White, J. Whitmore, M. J. Wilking, R. Winston, E.T. Worcester, M.
Worcester, T. Yamanaka, E. D. Zimmerman, R.F. Zukanovich | Measurement of the Decay KL -> pi0 e+ e- gamma | 6 pages, 7 figures, Submitted to Phys. Rev. D | Phys.Rev.D76:052001,2007 | 10.1103/PhysRevD.76.052001 | null | hep-ex | null | We report on a new measurement of the branching ratio B(KL -> pi0 e+ e-
gamma) using the KTeV detector. This analysis uses the full KTeV data set
collected from 1997 to 2000. We reconstruct 139 events over a background of 14,
which results in B(KL -> pi0 e+ e- gamma) = (1.62 +/- 0.14 (stat) +/- 0.09
(syst)) x 10^{-8}. This result supersedes the earlier KTeV measurement of this
branching ratio.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 17:04:40 GMT"
},
{
"version": "v2",
"created": "Wed, 25 Jul 2007 16:18:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"KTeV Collaboration",
"",
""
],
[
"Abouzaid",
"E.",
""
],
[
"Arenton",
"M.",
""
],
[
"Barker",
"A. R.",
""
],
[
"Bellantoni",
"L.",
""
],
[
"Blucher",
"E.",
""
],
[
"Bock",
"G. J.",
""
],
[
"Cheu",
"E.",
""
],
[
"Coleman",
"R.",
""
],
[
"Cox",
"B.",
""
],
[
"Erwin",
"A. R.",
""
],
[
"Escobar",
"C. O.",
""
],
[
"Glazov",
"A.",
""
],
[
"Golossanov",
"A.",
""
],
[
"Gomes",
"R. A.",
""
],
[
"Gouffon",
"P.",
""
],
[
"Hsiung",
"Y. B.",
""
],
[
"Jensen",
"D. A.",
""
],
[
"Kessler",
"R.",
""
],
[
"Kim",
"Y. J.",
""
],
[
"Kotera",
"K.",
""
],
[
"Ledovskoy",
"A.",
""
],
[
"McBride",
"P. L.",
""
],
[
"Monnier",
"E.",
""
],
[
"Nelson",
"K. S.",
""
],
[
"Nguyen",
"H.",
""
],
[
"Niclasen",
"R.",
""
],
[
"Phillips",
"D. G.",
"II"
],
[
"Ping",
"H.",
""
],
[
"Ramberg",
"E. J.",
""
],
[
"Ray",
"R. E.",
""
],
[
"Ronquest",
"M.",
""
],
[
"Santos",
"E.",
""
],
[
"Slater",
"W.",
""
],
[
"Smith",
"D.",
""
],
[
"Solomey",
"N.",
""
],
[
"Swallow",
"E. C.",
""
],
[
"Toale",
"P. A.",
""
],
[
"Tschirhart",
"R.",
""
],
[
"Velissaris",
"C.",
""
],
[
"Wah",
"Y. W.",
""
],
[
"Wang",
"J.",
""
],
[
"White",
"H. B.",
""
],
[
"Whitmore",
"J.",
""
],
[
"Wilking",
"M. J.",
""
],
[
"Winston",
"R.",
""
],
[
"Worcester",
"E. T.",
""
],
[
"Worcester",
"M.",
""
],
[
"Yamanaka",
"T.",
""
],
[
"Zimmerman",
"E. D.",
""
],
[
"Zukanovich",
"R. F.",
""
]
] |
0706.4075 | Ken Wharton | K.B. Wharton | A novel interpretation of the Klein-Gordon equation | v3: Extensively revised version accepted for publication by Found.
Phys | AIP Conf.Proc.962:339-343,2007; Found.Phys.40:313-332,2010 | 10.1063/1.2827330 10.1007/s10701-009-9398-2 | null | quant-ph gr-qc hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The covariant Klein-Gordon equation requires twice the boundary conditions of
the Schrodinger equation and does not have an accepted single-particle
interpretation. Instead of interpreting its solution as a probability wave
determined by an initial boundary condition, this paper considers the
possibility that the solutions are determined by both an initial and a final
boundary condition. By constructing an invariant joint probability distribution
from the size of the solution space, it is shown that the usual measurement
probabilities can nearly be recovered in the non-relativistic limit, provided
that neither boundary constrains the energy to a precision near hbar/T (where T
is the time duration between the boundary conditions). Otherwise, deviations
from standard quantum mechanics are predicted.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:27:00 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Mar 2008 18:31:57 GMT"
},
{
"version": "v3",
"created": "Fri, 11 Dec 2009 18:10:05 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Wharton",
"K. B.",
""
]
] |
0706.4076 | Amelia Sparavigna | A. Sparavigna | Phonons in lattices with rod-like particles | 16 pages, 9 figures | null | null | null | cond-mat.mtrl-sci | null | The paper studies the modes of vibrations of a lattice with rod-like
particles, in a continuum model where the sites of the lattice are the
connections among strings and rigid rods. In these structures then,
translational and rotational degrees of freedom are strongly coupled. We will
discuss in particular two-dimensional lattices with auxetic-like behaviour.
Auxetics are materials with a negative Poisson elastic parameter, meaning that
they have a lateral extension, instead to shrink, when they are stretched. We
assume as "auxetic-like" two-dimensional structures, structures which do not
collapse, when stretched in one of the in-plane directions. The presence of
rigid rod-like particles in the lattice prevents the shrinking of the membrane.
Complete bandgaps between acoustic and optical modes are observed in analogy
with the behaviour of crystalline materials.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 17:40:50 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Sparavigna",
"A.",
""
]
] |
0706.4077 | William Bryan | W. A. Bryan, E. M. L. English, J. McKenna, J. Wood, C. R. Calvert, R.
Torres, I. C. E. Turcu, J. L. Collier, I. D. Williams and W. R. Newell | Mapping the Evolution of Optically-Generated Rotational Wavepackets in a
Room Temperature Ensemble of D$_2$ | 4 pages, 3 figures. Accepted for publication in Phys. Rev. A. Full
reference to follow.. | Phys. Rev. A 76, 023414 (2007) | 10.1103/PhysRevA.76.023414 | null | quant-ph physics.atom-ph physics.chem-ph | null | A coherent superposition of rotational states in D$_2$ has been excited by
nonresonant ultrafast (12 femtosecond) intense (2 $\times$ 10$^{14}$
Wcm$^{-2}$) 800 nm laser pulses leading to impulsive dynamic alignment.
Field-free evolution of this rotational wavepacket has been mapped to high
temporal resolution by a time-delayed pulse, initiating rapid double
ionization, which is highly sensitive to the angle of orientation of the
molecular axis with respect to the polarization direction, $\theta$. The
detailed fractional revivals of the neutral D$_2$ wavepacket as a function of
$\theta$ and evolution time have been observed and modelled theoretically.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 17:52:58 GMT"
}
] | 2007-11-06T00:00:00 | [
[
"Bryan",
"W. A.",
""
],
[
"English",
"E. M. L.",
""
],
[
"McKenna",
"J.",
""
],
[
"Wood",
"J.",
""
],
[
"Calvert",
"C. R.",
""
],
[
"Torres",
"R.",
""
],
[
"Turcu",
"I. C. E.",
""
],
[
"Collier",
"J. L.",
""
],
[
"Williams",
"I. D.",
""
],
[
"Newell",
"W. R.",
""
]
] |
0706.4078 | Wegrzyn Pawel | Pawel Wegrzyn | Exact closed form analytical solutions for vibrating cavities | 17 pages, 7 figures | J. Phys. B: At. Mol. Opt. Phys. 40, 2621-2640 (2007) | 10.1088/0953-4075/40/13/008 | null | quant-ph | null | For one-dimensional vibrating cavity systems appearing in the standard
illustration of the dynamical Casimir effect, we propose an approach to the
construction of exact closed-form solutions. As new results, we obtain
solutions that are given for arbitrary frequencies, amplitudes and time
regions. In a broad range of parameters, a vibrating cavity model exhibits the
general property of exponential instability. Marginal behavior of the system
manifests in a power-like growth of radiated energy.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:08:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wegrzyn",
"Pawel",
""
]
] |
0706.4079 | Evelina Shamarova | Evelina Shamarova | Chernoff's theorem for evolution families | null | null | null | null | math.FA math.PR | null | A generalized version of Chernoff's theorem has been obtained. Namely, the
version of Chernoff's theorem for semigroups obtained in a paper by Smolyanov,
Weizsaecker, and Wittich is generalized for a time-inhomogeneous case. The main
theorem obtained in the current paper, Chernoff's theorem for evolution
families, deals with a family of time-dependent generators of semigroups $A_t$
on a Banach space, a two-parameter family of operators $Q_{t,t+\Delta t}$
satisfying the relation: $\frac{\partial}{\partial \Delta t}Q_{t,t+\Delta
t}|_{\Delta t = 0}=A_t$, whose products $Q_{t_i,t_{i+1}}... Q_{t_{k-1},t_k}$
are uniformly bounded for all subpartitions $s = t_0 < t_1 < >... < t_n = t$.
The theorem states that $Q_{t_0,t_1}... Q_{t_{n-1},t_n}$ converges to an
evolution family $U(s,t)$ solving a non-autonomous Cauchy problem. Furthermore,
the theorem is formulated for a particular case when the generators $A_t$ are
time dependent second order differential operators. Finally, an example of
application of this theorem to a construction of time-inhomogeneous diffusions
on a compact Riemannian manifold is given.
Keywords: Chernoff's theorem, evolution family, strongly continuous
semigroup, evolution families generated by manifold valued stochastic
processes.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:16:24 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Shamarova",
"Evelina",
""
]
] |
0706.4080 | Paola Testa | Paola Testa (MIT), Jeremy J. Drake (SAO), Giovanni Peres (Universita'
di Palermo), David P. Huenemoerder (MIT) | On X-ray Optical Depth in the Coronae of Active Stars | Accepted for publication on the Astrophysical Journal | Astrophys.J.665:1349-1360,2007 | 10.1086/519920 | null | astro-ph | null | We have investigated the optical thickness of the coronal plasma through the
analysis of high-resolution X-ray spectra of a large sample of active stars
observed with the High Energy Transmission Grating Spectrometer on Chandra. In
particular, we probed for the presence of significant resonant scattering in
the strong Lyman series lines arising from hydrogen-like oxygen and neon ions.
The active RS CVn-type binaries II Peg and IM Peg and the single M dwarf EV Lac
show significant optical depth. For these active coronae, the Lya/Lyb ratios
are significantly depleted as compared with theoretical predictions and with
the same ratios observed in similar active stars. Interpreting these decrements
in terms of resonance scattering of line photons out of the line-of-sight, we
are able to derive an estimate for the typical size of coronal structures, and
from these we also derive estimates of coronal filling factors. For all three
sources we find that the both the photon path length as a fraction of the
stellar radius, and the implied surface filling factors are very small and
amount to a few percent at most. The measured Lya/Lyb ratios are in good
agreement with APED theoretical predictions, thus indicating negligible optical
depth, for the other sources in our sample. We discuss the implications for
coronal structuring and heating flux requirements. For the stellar sample as a
whole, the data suggest increasing quenching of Lya relative to Lyb as function
of both L_x/L_bol and the density-sensitive MgXI forbidden to intercombination
line ratio, as might generally be expected.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:17:59 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Testa",
"Paola",
"",
"MIT"
],
[
"Drake",
"Jeremy J.",
"",
"SAO"
],
[
"Peres",
"Giovanni",
"",
"Universita'\n di Palermo"
],
[
"Huenemoerder",
"David P.",
"",
"MIT"
]
] |
0706.4081 | Jon F. Carlson | Jon F. Carlson and Jacques Thevenaz | The classification of torsion endo-trivial modules | 61 pages, published version | Ann. of Math. (2) 162 (2005), no. 2, 823--883 | null | null | math.GR | null | This paper is a major step in the classification of endotrivial modules over
p-groups. Let G be a finite p-group and k be a field of characteristic p. A
kG-module M is an endo-trivial module if {\End_k(M)\cong k\oplus F} as
kG-modules, where F is a free module. The classification of endo-trivial
modules is the crucial step for understanding the more general class of
endo-permutation modules. The endo-permutation modules play an important role
in module theory, in particular as source modules, and in block theory where
they appear in the description of source algebras. Endo-trivial modules are
also important in the study of both derived equivalences and stable
equivalences of group algebras and block algebras.
The collection of isomorphism classes of endo-trivial modules modulo
projectives is an abelian group under tensor product. The main result of this
paper is that this group is torsion free except in the case that G is cyclic,
quaternion or semi-dihedral. Hence for any p-group which is not cyclic,
quaternion or semi-dihedral and any finitely generated kG-module M, if M
\otimes_k M \otimes_k ... \otimes_k M \cong k \oplus P for some projective
module P and some finite number of tensor products, then M \cong k \oplus Q for
some projective module Q. The proof uses a reduction to the cases in which G is
an extraspecial or almost extraspecial p-group, proved in a previous paper of
the authors, and makes extensive use of the theory of support varieties for
modules.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:19:13 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Carlson",
"Jon F.",
""
],
[
"Thevenaz",
"Jacques",
""
]
] |
0706.4082 | Jon Wilkening | Jon Wilkening | Inf-sup estimates for the Stokes problem in a periodic channel | 18 pages, 4 figures | null | null | null | math.AP math.FA | null | We derive estimates of the Babu\u{s}ka-Brezzi inf-sup constant $\beta$ for
two-dimensional incompressible flow in a periodic channel with one flat
boundary and the other given by a periodic, Lipschitz continuous function $h$.
If $h$ is a constant function (so the domain is rectangular), we show that
periodicity in one direction but not the other leads to an interesting
connection between $\beta$ and the unitary operator mapping the Fourier sine
coefficients of a function to its Fourier cosine coefficients. We exploit this
connection to determine the dependence of $\beta$ on the aspect ratio of the
rectangle. We then show how to transfer this result to the case that $h$ is
$C^{1,1}$ or even $C^{0,1}$ by a change of variables. We avoid non-constructive
theorems of functional analysis in order to explicitly exhibit the dependence
of $\beta$ on features of the geometry such as the aspect ratio, the maximum
slope, and the minimum gap thickness (if $h$ passes near the substrate). We
give an example to show that our estimates are optimal in their dependence on
the minimum gap thickness in the $C^{1,1}$ case, and nearly optimal in the
Lipschitz case.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:19:13 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Wilkening",
"Jon",
""
]
] |
0706.4083 | Jose Eduardo Costa Dr. | J. E. S. Costa, E. Michel, J. Pena, O. Creevey, Z. P. Li, M.
Chevreton, J. A. Belmonte, M. Alvarez, L. Fox Machado, L. Parrao, F. Perez
Hernendez, A. Fernandez, J. R. Fremy, S. Pau, R. Alonso | Pulsational frequencies of the eclipsing delta-Scuti star HD 172189 | 6 pages, 7 figures | Astron.Astrophys.468:637-642,2007 | 10.1051/0004-6361:20065784 | null | astro-ph | null | The eclipsing delta-Scuti star HD 172189 is a probable member of the open
cluster IC 4756 and a promising candidate target for the CoRoT mission.
The detection of pulsation modes is the first step in the asteroseismological
study of the star. Further, the calculation of the orbital parameters of the
binary system allows us to make a dynamical determination of the mass of the
star, which works as an important constraint to test and calibrate the
asteroseismological models.
From a detailed frequency analysis of 210 hours of photometric data of HD
172189 obtained from the STEPHI XIII campaign we have identified six pulsation
frequencies with a confidence level of 99% and a seventh with a 65% confidence
level in the range between 100-300 uHz. In addiction, three eclipses were
observed during the campaign, allowing us to improve the determination of the
orbital period of the system.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:38:59 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Costa",
"J. E. S.",
""
],
[
"Michel",
"E.",
""
],
[
"Pena",
"J.",
""
],
[
"Creevey",
"O.",
""
],
[
"Li",
"Z. P.",
""
],
[
"Chevreton",
"M.",
""
],
[
"Belmonte",
"J. A.",
""
],
[
"Alvarez",
"M.",
""
],
[
"Machado",
"L. Fox",
""
],
[
"Parrao",
"L.",
""
],
[
"Hernendez",
"F. Perez",
""
],
[
"Fernandez",
"A.",
""
],
[
"Fremy",
"J. R.",
""
],
[
"Pau",
"S.",
""
],
[
"Alonso",
"R.",
""
]
] |
0706.4084 | Hasan Yuksel | Hasan Yuksel, John F. Beacom (Ohio State U.), Casey R. Watson
(Millikin U.) | Strong Upper Limits on Sterile Neutrino Warm Dark Matter | 4 pages, 2 figures; minor revisions, accepted for publication in
Physical Review Letters | Phys.Rev.Lett.101:121301,2008 | 10.1103/PhysRevLett.101.121301 | null | astro-ph hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Sterile neutrinos are attractive dark matter candidates. Their parameter
space of mass and mixing angle has not yet been fully tested despite intensive
efforts that exploit their gravitational clustering properties and radiative
decays. We use the limits on gamma-ray line emission from the Galactic Center
region obtained with the SPI spectrometer on the INTEGRAL satellite to set new
constraints, which improve on the earlier bounds on mixing by more than two
orders of magnitude, and thus strongly restrict a wide and interesting range of
models.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:54:41 GMT"
},
{
"version": "v2",
"created": "Fri, 5 Sep 2008 19:13:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Yuksel",
"Hasan",
"",
"Ohio State U."
],
[
"Beacom",
"John F.",
"",
"Ohio State U."
],
[
"Watson",
"Casey R.",
"",
"Millikin U."
]
] |
0706.4085 | Yoram Alhassid | Y. Alhassid, G.F. Bertsch, L. Fang | A new effective interaction for the trapped Fermi gas | 4 pages, 3 figures | Phys. Rev. Lett. 100, 230401 (2008) | 10.1103/PhysRevLett.100.230401 | null | cond-mat.other nucl-th physics.atom-ph | null | We apply the configuration-interaction method to calculate the spectra of
two-component Fermi systems in a harmonic trap, studying the convergence of the
method at the unitary interaction limit. We find that for a fixed
regularization of the two-body interaction the convergence is exponential or
better in the truncation parameter of the many-body space. However, the
conventional regularization is found to have poor convergence in the
regularization parameter, with an error that scales as a low negative power of
this parameter. We propose a new regularization of the two-body interaction
that produces exponential convergence for systems of three and four particles.
From the systematics, we estimate the ground-state energy of the
four-particle system to be (5.05 +- 0.024)hbar omega.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:52:25 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Alhassid",
"Y.",
""
],
[
"Bertsch",
"G. F.",
""
],
[
"Fang",
"L.",
""
]
] |
0706.4086 | Winfried Zimdahl | R. Colistete Jr., J.C. Fabris, J. Tossa and W. Zimdahl | Bulk Viscous Cosmology | 25 pages, 5 figures, comments and references added, accepted for
publication in PRD | Phys.Rev.D76:103516,2007 | 10.1103/PhysRevD.76.103516 | null | astro-ph gr-qc hep-th | null | We propose a scenario in which the dark components of the Universe are
manifestations of a single bulk viscous fluid. Using dynamical system methods,
a qualitative study of the homogeneous, isotropic background scenario is
performed in order to determine the phase space of all possible solutions. The
specific model which we investigate shares similarities with a generalized
Chaplygin gas in the background but is characterized by non-adiabatic pressure
perturbations. This model is tested against supernova type Ia and matter power
spectrum data. Different from other unified descriptions of dark matter and
dark energy, the matter power spectrum is well behaved, i.e., there are no
instabilities or oscillations on small perturbation scales. The model is
competitive in comparison with the currently most popular proposals for the
description of the cosmological dark sector.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:51:45 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 07:53:48 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Colistete",
"R.",
"Jr."
],
[
"Fabris",
"J. C.",
""
],
[
"Tossa",
"J.",
""
],
[
"Zimdahl",
"W.",
""
]
] |
0706.4087 | Samvel Ter-Antonyan V | S. V. Ter-Antonyan | Mutually compensative pseudo solutions of primary energy spectra in the
knee region | Accepted for publication in Astroparticle Physics | Astropart.Phys.28:321-326,2007 | 10.1016/j.astropartphys.2007.06.004 | null | astro-ph | null | The problem of the uniqueness of solutions during the evaluation of primary
energy spectra in the knee region using an extensive air shower (EAS) data set
and the EAS inverse approach is investigated. It is shown that the unfolding of
primary energy spectra in the knee region leads to mutually compensative pseudo
solutions. These solutions may be the reason for the observed disagreements in
the elementary energy spectra of cosmic rays in the 1-100 PeV energy range
obtained from different experiments.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:55:27 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Ter-Antonyan",
"S. V.",
""
]
] |
0706.4088 | Jos\'e Prieto | J.L. Prieto, P.M. Garnavich, M.M. Phillips, D.L. DePoy, J.Parrent, D.
Pooley, V.V. Dwarkadas, E. Baron, B. Bassett, A. Becker, D. Cinabro, F.
DeJongh, B. Dilday, M. Doi, J.A. Frieman, C.J. Hogan, J. Holtzman, S. Jha, R.
Kessler, K. Konishi, H. Lampeitl, J. Marriner, J. L. Marshall, G. Miknaitis,
R.C. Nichol, A.G. Riess, M.W. Richmond, R. Romani, M. Sako, D.P. Schneider,
M. Smith, N. Takanashi, K. Tokita, K. van der Heyden, N. Yasuda, C. Zheng,
J.C. Wheeler, J. Barentine, J. Dembicky, J. Eastman, S. Frank, W. Ketzeback,
R.J. McMillan, N. Morrell, G. Folatelli, C. Contreras, C.R. Burns, W. L.
Freedman, S. Gonzalez, M. Hamuy, W. Krzeminski, B.F. Madore, D. Murphy, S.E.
Persson, M. Roth, N.B. Suntzeff | A Study of the Type Ia/IIn Supernova 2005gj from X-ray to the Infrared:
Paper I | 63 pages, 16 figures, submitted to AJ | null | null | null | astro-ph | null | We present extensive ugrizYHJK photometry and optical spectroscopy of SN
2005gj obtained by the SDSS-II and CSP Supernova Projects, which give excellent
coverage during the first 150 days after the time of explosion. These data show
that SN 2005gj is the second clear case, after SN 2002ic, of a thermonuclear
explosion in a dense circumstellar environment. Both the presence of singly and
doubly ionized iron-peak elements (FeIII and weak SII, SiII) near maximum light
as well as the spectral evolution show that SN 2002ic-like events are Type Ia
explosions. Independent evidence comes from the exponential decay in luminosity
of SN 2005gj, pointing to an exponential density distribution of the ejecta.
The interaction of the supernova ejecta with the dense circumstellar medium is
stronger than in SN 2002ic: (1) the supernova lines are weaker; (2) the Balmer
emission lines are more luminous; and (3) the bolometric luminosity is higher
close to maximum light. The velocity evolution of the Halpha components suggest
that the CSM around SN 2005gj is clumpy and it has a flatter density
distribution compared with the steady wind solution, in agreement with SN
2002ic. An early X-ray observation with Chandra gives an upper-limit on the
mass loss rate from the companion of < 2x10^{-4} Msun/yr.
| [
{
"version": "v1",
"created": "Thu, 28 Jun 2007 18:31:46 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Prieto",
"J. L.",
""
],
[
"Garnavich",
"P. M.",
""
],
[
"Phillips",
"M. M.",
""
],
[
"DePoy",
"D. L.",
""
],
[
"Parrent",
"J.",
""
],
[
"Pooley",
"D.",
""
],
[
"Dwarkadas",
"V. V.",
""
],
[
"Baron",
"E.",
""
],
[
"Bassett",
"B.",
""
],
[
"Becker",
"A.",
""
],
[
"Cinabro",
"D.",
""
],
[
"DeJongh",
"F.",
""
],
[
"Dilday",
"B.",
""
],
[
"Doi",
"M.",
""
],
[
"Frieman",
"J. A.",
""
],
[
"Hogan",
"C. J.",
""
],
[
"Holtzman",
"J.",
""
],
[
"Jha",
"S.",
""
],
[
"Kessler",
"R.",
""
],
[
"Konishi",
"K.",
""
],
[
"Lampeitl",
"H.",
""
],
[
"Marriner",
"J.",
""
],
[
"Marshall",
"J. L.",
""
],
[
"Miknaitis",
"G.",
""
],
[
"Nichol",
"R. C.",
""
],
[
"Riess",
"A. G.",
""
],
[
"Richmond",
"M. W.",
""
],
[
"Romani",
"R.",
""
],
[
"Sako",
"M.",
""
],
[
"Schneider",
"D. P.",
""
],
[
"Smith",
"M.",
""
],
[
"Takanashi",
"N.",
""
],
[
"Tokita",
"K.",
""
],
[
"van der Heyden",
"K.",
""
],
[
"Yasuda",
"N.",
""
],
[
"Zheng",
"C.",
""
],
[
"Wheeler",
"J. C.",
""
],
[
"Barentine",
"J.",
""
],
[
"Dembicky",
"J.",
""
],
[
"Eastman",
"J.",
""
],
[
"Frank",
"S.",
""
],
[
"Ketzeback",
"W.",
""
],
[
"McMillan",
"R. J.",
""
],
[
"Morrell",
"N.",
""
],
[
"Folatelli",
"G.",
""
],
[
"Contreras",
"C.",
""
],
[
"Burns",
"C. R.",
""
],
[
"Freedman",
"W. L.",
""
],
[
"Gonzalez",
"S.",
""
],
[
"Hamuy",
"M.",
""
],
[
"Krzeminski",
"W.",
""
],
[
"Madore",
"B. F.",
""
],
[
"Murphy",
"D.",
""
],
[
"Persson",
"S. E.",
""
],
[
"Roth",
"M.",
""
],
[
"Suntzeff",
"N. B.",
""
]
] |
0706.4089 | Michael Cooper | Michael C. Cooper, Jeffrey A. Newman, Benjamin J. Weiner, Renbin Yan,
Christopher N. A. Willmer, Kevin Bundy, Alison L. Coil, Christopher J.
Conselice, Marc Davis, S. M. Faber, Brian F. Gerke, Puragra Guhathakurta,
David C. Koo, Kai G. Noeske | The DEEP2 Galaxy Redshift Survey: The Role of Galaxy Environment in the
Cosmic Star-Formation History | 20 pages including 18 figures and 4 tables in emulateapj format;
submitted to MNRAS | null | 10.1111/j.1365-2966.2007.12613.x | null | astro-ph | null | Using galaxy samples drawn from the Sloan Digital Sky Survey and the DEEP2
Galaxy Redshift Survey, we study the relationship between star formation and
environment at z ~ 0.1 and z ~ 1. We estimate the total star-formation rate
(SFR) and specific star-formation rate (sSFR) for each galaxy according to the
measured [O II] nebular line luminosity, corrected using empirical calibrations
to match more robust SFR indicators. Echoing previous results, we find that in
the local Universe star formation depends on environment such that galaxies in
regions of higher overdensity, on average, have lower star-formation rates and
longer star-formation timescales than their counterparts in lower-density
regions. At z ~ 1, we show that the relationship between specific SFR and
environment mirrors that found locally. However, we discover that the
relationship between total SFR and overdensity at z ~ 1 is inverted relative to
the local relation. This observed evolution in the SFR-density relation is
driven, in part, by a population of bright, blue galaxies in dense environments
at z ~ 1. This population, which lacks a counterpart at z ~ 0, is thought to
evolve into members of the red sequence from z ~ 1 to z ~ 0. Finally, we
conclude that environment does not play a dominant role in the cosmic
star-formation history at z < 1: the dependence of the mean galaxy SFR on local
galaxy density at constant redshift is small compared to the decline in the
global SFR space density over the last 7 Gyr.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:00:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cooper",
"Michael C.",
""
],
[
"Newman",
"Jeffrey A.",
""
],
[
"Weiner",
"Benjamin J.",
""
],
[
"Yan",
"Renbin",
""
],
[
"Willmer",
"Christopher N. A.",
""
],
[
"Bundy",
"Kevin",
""
],
[
"Coil",
"Alison L.",
""
],
[
"Conselice",
"Christopher J.",
""
],
[
"Davis",
"Marc",
""
],
[
"Faber",
"S. M.",
""
],
[
"Gerke",
"Brian F.",
""
],
[
"Guhathakurta",
"Puragra",
""
],
[
"Koo",
"David C.",
""
],
[
"Noeske",
"Kai G.",
""
]
] |
0706.4090 | Teet Ord | N.Voropajeva, T.Ord | Correlation in the velocity of a Brownian particle induced by frictional
anisotropy and magnetic field | 7 pages, 2 figures | null | 10.1016/j.physleta.2007.10.098 | null | cond-mat.stat-mech | null | We study the motion of charged Brownian particles in an external magnetic
field. It is found that a correlation appears between the components of
particle velocity in the case of anisotropic friction, approaching
asymptotically zero in the stationary limit. If magnetic field is smaller
compared to the critical value, determined by frictional anisotropy, the
relaxation of the correlation is non-oscillating in time. However, in a larger
magnetic field this relaxation becomes oscillating. The phenomenon is related
to the statistical dependence of the components of transformed random force
caused by the simultaneous influence of magnetic field and anisotropic
dissipation.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:00:16 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 08:44:31 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Voropajeva",
"N.",
""
],
[
"Ord",
"T.",
""
]
] |
0706.4091 | Naveen Reddy | Naveen A. Reddy (NOAO/Caltech), Charles C. Steidel (Caltech), Max
Pettini (IoA), Kurt L. Adelberger (McKinsey), Alice E. Shapley (Princeton),
Dawn K. Erb (CfA), Mark Dickinson (NOAO) | Multi-Wavelength Constraints on the Cosmic Star Formation History from
Spectroscopy: the Rest-Frame UV, H-alpha, and Infrared Luminosity Functions
at Redshifts 1.9<z<3.4 | 40 pages, 28 figures, 12 tables; accepted for publication in ApJ | null | 10.1086/521105 | null | astro-ph | null | We use a sample of rest-frame UV selected and spectroscopically observed
galaxies at redshifts 1.9<z<3.4, combined with ground-based spectroscopic
H-alpha and Spitzer MIPS 24 micron data, to derive the most robust measurements
of the rest-frame UV, H-alpha, and infrared (IR) luminosity functions (LFs) at
these redshifts. Our sample is by far the largest of its kind, with over 2000
spectroscopic redshifts in the range 1.9<z<3.4 and ~15000 photometric
candidates in 29 independent fields covering a total area of almost a square
degree. Our method for computing the LFs takes into account a number of
systematic effects, including photometric scatter, Ly-alpha perturbations to
optical colors, and contaminants. Taking into account the latter, we find no
evidence for an excess of UV-bright galaxies over what was inferred in early
z~3 LBG studies. The UV LF appears to undergo little evolution between z~4 and
z~2. Corrected for extinction, the UV luminosity density (LD) at z~2 is at
least as large as the value at z~3 and a factor of ~9 larger than the value at
z~6, primarily reflecting an increase in the number density of bright galaxies
between z~6 and z~2. Our analysis yields the first constraints anchored by
extensive spectroscopy on the IR and bolometric LFs for faint and moderately
luminous (L[bol]<10^12 L_sun) galaxies. Adding the IR to the emergent UV
luminosity, incorporating independent measurements of the LD from ULIRGs, and
assuming realistic dust attenuation values for UV-faint galaxies, indicates
that galaxies with L[bol]<10^12 L_sun account for ~80% of the bolometric LD and
SFRD at z~2-3. Our multi-wavelength constraints on the global SFRD indicate
that approximately one-third of the present-day stellar mass density was formed
in sub-ultraluminous galaxies between redshifts z=1.9-3.4. [Abridged]
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:00:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Reddy",
"Naveen A.",
"",
"NOAO/Caltech"
],
[
"Steidel",
"Charles C.",
"",
"Caltech"
],
[
"Pettini",
"Max",
"",
"IoA"
],
[
"Adelberger",
"Kurt L.",
"",
"McKinsey"
],
[
"Shapley",
"Alice E.",
"",
"Princeton"
],
[
"Erb",
"Dawn K.",
"",
"CfA"
],
[
"Dickinson",
"Mark",
"",
"NOAO"
]
] |
0706.4092 | Ricardo Avila | Ricardo E. Avila | Distinguishing Bulk-Diffusion from Surface-Desorption Limited Gas
Release Processes | 5 pages, 3 figures. Published as Ricardo E. Avila, Jap. J. Appl.
Phys. 45, 9254 (2006) | Ricardo E. Avila, Jap. J. Appl. Phys. 45, 9254 (2006) | 10.1143/JJAP.45.9254 | null | cond-mat.other cond-mat.mtrl-sci cond-mat.stat-mech | null | The release of a gas limited by surface desorption, or by diffusion from the
bulk of spherical pebbles is revisited. A method is proposed to identify the
release limiting process, by comparing a partial temperature ramp, up to
slightly beyond the release peak, followed by a rapid temperature drop, to a
second, full release ramp. Comparing the release curve from the second ramp to
that of the first one: i) the peak is unmoved in first order desorption
kinetics, and moves to higher temperature in the other cases, ii) as compared
to the Arrhenius analysis of the first curve, that of the second is, again,
identical in first order kinetics, in second order desorption it maintains the
slope but lowers the intercept at the reciprocal temperature origin, and it is
inapplicable in bulk diffusion kinetics.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:08:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Avila",
"Ricardo E.",
""
]
] |
0706.4093 | Brian Siana | Brian Siana (1), Harry I. Teplitz (1), James Colbert (1), Henry C.
Ferguson (2), Mark Dickinson (3), Thomas M. Brown (2), Christopher J.
Conselice (4), Duilia F. de Mello (5,6), Jonathan P. Gardner (6), Mauro
Giavalisco (7), Felipe Menanteau (8) ((1) Spitzer Science Center, (2) STScI,
(3) NOAO, (4) Nottingham, (5) Catholic University, (6) Goddard, (7) UMass,
(8) Rutgers) | New Constraints on the Lyman Continuum Escape Fraction at z~1.3 | Accepted for publication in ApJ. aastex format. 39 pages, 11 figures | null | 10.1086/521185 | null | astro-ph | null | We examine deep far-ultraviolet (1600 Angstrom) imaging of the Hubble Deep
Field-North (HDFN) and the Hubble Ultra Deep Field (HUDF) to search for leaking
Lyman continuum radiation from starburst galaxies at z~1.3. There are 21
(primarily sub-L*) galaxies with spectroscopic redshifts between 1.1<z<1.5 and
none are detected in the far-UV. We fit stellar population templates to the
galaxies' optical/near-infrared SEDs to determine the starburst age and level
of dust attenuation, giving an accurate estimate of the intrinsic Lyman
continuum ratio, f_1500/f_700, and allowing a conversion from f_700 limits to
relative escape fractions. We show that previous high-redshift studies may have
underestimated the amplitude of the Lyman Break, and thus the relative escape
fraction, by a factor of ~2. Once the starburst age and intergalactic HI
absorption are accounted for, 18 galaxies in our sample have limits to the
relative escape fraction, f_esc,rel < 1.0 with some limits as low as f_esc,rel
< 0.10 and a stacked limit of f_esc,rel < 0.08. This demonstrates, for the
first time, that most sub-L* galaxies at high redshift do not have large escape
fractions. When combined with a similar study of more luminous galaxies at the
same redshift we show that, if all star-forming galaxies at z~1 have similar
relative escape fractions, the value must be less than 0.14 (3 sigma). We also
show that less than 20% (3 sigma) of star-forming galaxies at z~1 have relative
escape fractions near unity. These limits contrast with the large escape
fractions found at z~3 and suggest that the average escape fraction has
decreased between z~3 and z~1. (Abridged)
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:09:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Siana",
"Brian",
""
],
[
"Teplitz",
"Harry I.",
""
],
[
"Colbert",
"James",
""
],
[
"Ferguson",
"Henry C.",
""
],
[
"Dickinson",
"Mark",
""
],
[
"Brown",
"Thomas M.",
""
],
[
"Conselice",
"Christopher J.",
""
],
[
"de Mello",
"Duilia F.",
""
],
[
"Gardner",
"Jonathan P.",
""
],
[
"Giavalisco",
"Mauro",
""
],
[
"Menanteau",
"Felipe",
""
]
] |
0706.4094 | Matthew Hastings | M. B. Hastings | Quantum Belief Propagation | 4 pages, 1 figure; revised time estimates due to improved
implementation. Typographical corrections to Eq. 7 made; thanks to David
Poulin for pointing out the mistake | Phys. Rev. B Rapids 76, 201102 (2007) | 10.1103/PhysRevB.76.201102 | null | cond-mat.str-el quant-ph | null | We present an accurate numerical algorithm, called quantum belief propagation
(QBP), for simulation of one-dimensional quantum systems at non-zero
temperature. The algorithm exploits the fact that quantum effects are
short-range in these systems at non-zero temperature, decaying on a length
scale inversely proportional to the temperature. We compare to exact results on
a spin-1/2 Heisenberg chain. Even a very modest calculation, requiring
diagonalizing only 10-by-10 matrices, reproduces the peak susceptibility with a
relative error of less than $10^{-5}$, while more elaborate calculations
further reduce the error.
| [
{
"version": "v1",
"created": "Thu, 28 Jun 2007 17:33:09 GMT"
},
{
"version": "v2",
"created": "Sun, 1 Jul 2007 22:23:49 GMT"
},
{
"version": "v3",
"created": "Thu, 7 Feb 2008 17:45:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hastings",
"M. B.",
""
]
] |
0706.4095 | Ilya Kapovich | Ilya Kapovich and Paul Schupp | Some Quantitative Aspects of Fractional Computability | null | null | null | null | math.GR cs.CC | null | Motivated by results on generic-case complexity in group theory, we apply the
ideas of effective Baire category and effective measure theory to study
complexity classes of functions which are "fractionally computable" by a
partial algorithm. For this purpose it is crucial to specify an allowable
effective density, $\delta$, of convergence for a partial algorithm. The set
$\mathcal{FC}(\delta)$ consists of all total functions $ f: \Sigma^\ast \to
\{0,1 \}$ where $\Sigma$ is a finite alphabet with $|\Sigma| \ge 2$ which are
"fractionally computable at density $\delta$". The space $\mathcal{FC}(\delta)
$ is effectively of the second category while any fractional complexity class,
defined using $\delta$ and any computable bound $\beta$ with respect to an
abstract Blum complexity measure, is effectively meager. A remarkable result of
Kautz and Miltersen shows that relative to an algorithmically random oracle
$A$, the relativized class $\mathcal{NP}^A$ does not have effective polynomial
measure zero in $\mathcal{E}^A$, the relativization of strict exponential time.
We define the class $\mathcal{UFP}^A$ of all languages which are fractionally
decidable in polynomial time at ``a uniform rate'' by algorithms with an oracle
for $A$. We show that this class does have effective polynomial measure zero in
$\mathcal{E}^A$ for every oracle $A$. Thus relaxing the requirement of
polynomial time decidability to hold only for a fraction of possible inputs
does not compensate for the power of nondeterminism in the case of random
oracles.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:26:19 GMT"
}
] | 2007-06-30T00:00:00 | [
[
"Kapovich",
"Ilya",
""
],
[
"Schupp",
"Paul",
""
]
] |
0706.4096 | Natalia Ivanova | N. Ivanova, C. Heinke, F.A. Rasio, K. Belczynski, J. Fregeau | Formation and evolution of compact binaries in globular clusters: II.
Binaries with neutron stars | 25 pages, 7 figures, 12 tables, MNRAS accepted | null | 10.1111/j.1365-2966.2008.13064.x | LA-UR-07-8455 | astro-ph | null | In this paper, the second of a series, we study the stellar dynamical and
evolutionary processes leading to the formation of compact binaries containing
neutron stars (NSs) in dense globular clusters (GCs). For this study, 70 dense
clusters were simulated independently, with a total stellar mass ~2x10^7Msun,
exceeding the total mass of all dense GCs in our Galaxy.
We find that, in order to reproduce the empirically derived formation rate of
low-mass X-ray binaries (LMXBs), we must assume that NSs can be formed via
electron-capture supernovae (ECS) with typical natal kicks smaller than in
core-collapse supernovae. Our results explain the observed dependence of the
number of LMXBs on ``collision number'' as well as the large scatter observed
between different GCs. We predict that the number of quiescent LMXBs in
different GCs should not have a strong metallicity dependence. In our cluster
model the following mass-gaining events create populations of MSPs that do not
match the observations: (i) accretion during a common envelope event with a NS
formed through ECS, and (ii) mass transfer (MT) from a WD donor. Some processes
lead only to a mild recycling. In addition, for MSPs, we distinguish
low-magnetic-field (long-lived) and high-magnetic-field (short-lived)
populations. With this distinction and by considering only those mass-gaining
events that appear to lead to NS recycling, we obtain good agreement of our
models with the numbers and characteristics of observed MSPs in 47 Tuc and
Terzan 5, as well as with the cumulative statistics for MSPs detected in GCs of
different dynamical properties. We find that significant production of merging
double NSs potentially detectable as short gamma-ray bursts occurs only in very
dense, most likely core-collapsed GCs. (abridged)
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:57:01 GMT"
},
{
"version": "v2",
"created": "Fri, 1 Feb 2008 19:52:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ivanova",
"N.",
""
],
[
"Heinke",
"C.",
""
],
[
"Rasio",
"F. A.",
""
],
[
"Belczynski",
"K.",
""
],
[
"Fregeau",
"J.",
""
]
] |
0706.4097 | Peter Wong | Lucilia Borsari, Fernanda Cardona, and Peter Wong | Equivariant path fields on topological manifolds | 17 pages, 6 figures | Topol. Methods Nonlinear Anal. 33 (2009), no. 1, 1--15 | null | null | math.AT | null | A classical theorem of H. Hopf asserts that a closed connected smooth
manifold admits a nowhere vanishing vector field if and only if its Euler
characteristic is zero. R. Brown generalized Hopf's result to topological
manifolds, replacing vector fields with path fields. In this note, we give an
equivariant analog of Brown's theorem for locally smooth $G$-manifolds where
$G$ is a finite group.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 20:55:54 GMT"
}
] | 2011-05-11T00:00:00 | [
[
"Borsari",
"Lucilia",
""
],
[
"Cardona",
"Fernanda",
""
],
[
"Wong",
"Peter",
""
]
] |
0706.4098 | Dawid Borycki Mr | Dawid Borycki | A superconductor with 4-fermion attraction perturbed by magnetic
impurities | 21 pages, 3 figures | null | 10.1140/epjb/e2008-00328-1 | null | cond-mat.supr-con | null | A superconductor with 4-fermion attraction, considered by Ma\'{c}kowiak and
Tarasewicz is modified by adding to the Hamiltonian a long-range magnetic
interaction $V$ between conduction fermions and localized distinguishable spin
1/2 magnetic impurities. $V$ has the form of a reduced s-d interaction. An
upper and lower bound to the system's free energy density $f(H,\beta)$ is
derived and the two bounds are shown to coalesce in the thermodynamic limit.
The resulting mean-field equations for the gap $\Delta$ and a parameter $y$,
characterizing the impurity subsystem are solved and the solution minimizing
$f$ is found for various values of magnetic coupling constant $g$ and impurity
concentration. The phase diagrams of the system are depicted with five distinct
phases: the normal phase, unperturbed superconducting phase, perturbed
superconducting phase with nonzero gap in the excitation spectrum, perturbed
gapless superconducting phase and impurity phase with completely suppressed
superconductivity.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:05:19 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Mar 2008 17:56:40 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Borycki",
"Dawid",
""
]
] |
0706.4099 | Benny Sudakov | Noga Alon and Benny Sudakov | On graphs with subgraphs of large independence numbers | null | null | null | null | math.CO | null | Let G be a graph on n vertices in which every induced subgraph on s=\log^3 n
vertices has an independent set of size at least t=\log n. What is the largest
q=q(n) so that every such G must contain an independent set of size at least q
? This is one of several related questions raised by Erdos and Hajnal. We show
that q(n)=\Theta(\log^2 n/\log \log n), investigate the more general problem
obtained by changing the parameters s and t, and discuss the connection to a
related Ramsey-type problem.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:08:00 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Alon",
"Noga",
""
],
[
"Sudakov",
"Benny",
""
]
] |
0706.4100 | Benny Sudakov | Noga Alon, Michael Krivelevich and Benny Sudakov | Embedding nearly-spanning bounded degree trees | null | null | null | null | math.CO | null | We derive a sufficient condition for a sparse graph G on n vertices to
contain a copy of a tree T of maximum degree at most d on (1-\epsilon)n
vertices, in terms of the expansion properties of G. As a result we show that
for fixed d\geq 2 and 0<\epsilon<1, there exists a constant c=c(d,\epsilon)
such that a random graph G(n,c/n) contains almost surely a copy of every tree T
on (1-\epsilon)n vertices with maximum degree at most d. We also prove that if
an (n,D,\lambda)-graph G (i.e., a D-regular graph on n vertices all of whose
eigenvalues, except the first one, are at most \lambda in their absolute
values) has large enough spectral gap D/\lambda as a function of d and
\epsilon, then G has a copy of every tree T as above.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:13:21 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Alon",
"Noga",
""
],
[
"Krivelevich",
"Michael",
""
],
[
"Sudakov",
"Benny",
""
]
] |
0706.4101 | Benny Sudakov | Benny Sudakov | Making a K_4-free graph bipartite | null | null | null | null | math.CO | null | We show that every K_4-free graph G with n vertices can be made bipartite by
deleting at most n^2/9 edges. Moreover, the only extremal graph which requires
deletion of that many edges is a complete 3-partite graph with parts of size
n/3. This proves an old conjecture of P. Erdos.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:16:39 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Sudakov",
"Benny",
""
]
] |
0706.4102 | Benny Sudakov | Benny Sudakov | Ramsey numbers and the size of graphs | null | null | null | null | math.CO | null | For two graph H and G, the Ramsey number r(H, G) is the smallest positive
integer n such that every red-blue edge coloring of the complete graph K_n on n
vertices contains either a red copy of H or a blue copy of G. Motivated by
questions of Erdos and Harary, in this note we study how the Ramsey number
r(K_s, G) depends on the size of the graph G. For s \geq 3, we prove that for
every G with m edges, r(K_s,G) \geq c (m/\log m)^{\frac{s+1}{s+3}} for some
positive constant c depending only on s. This lower bound improves an earlier
result of Erdos, Faudree, Rousseau, and Schelp, and is tight up to a
polylogarithmic factor when s=3. We also study the maximum value of r(K_s,G) as
a function of m.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:21:22 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Sudakov",
"Benny",
""
]
] |
0706.4103 | Jon Wilkening | Jon Wilkening | Practical Error Estimates for Reynolds' Lubrication Approximation and
its Higher Order Corrections | 43 pages, 10 figures, 4 tables; introduction expanded, 9 references
added, additional numerical results reported | SIAM J. Math Anal, 41/2 (2009), pp. 588-630 | 10.1137/070695447 | null | math.AP math-ph math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Reynolds' lubrication approximation is used extensively to study flows
between moving machine parts, in narrow channels, and in thin films. The
solution of Reynolds' equation may be thought of as the zeroth order term in an
expansion of the solution of the Stokes equations in powers of the aspect ratio
$\epsilon$ of the domain. In this paper, we show how to compute the terms in
this expansion to arbitrary order on a two-dimensional, $x$-periodic domain and
derive rigorous, a-priori error bounds for the difference between the exact
solution and the truncated expansion solution. Unlike previous studies of this
sort, the constants in our error bounds are either independent of the function
$h(x)$ describing the geometry, or depend on $h$ and its derivatives in an
explicit, intuitive way. Specifically, if the expansion is truncated at order
$2k$, the error is $O(\epsilon^{2k+2})$ and $h$ enters into the error bound
only through its first and third inverse moments $\int_0^1 h(x)^{-m} dx$,
$m=1,3$ and via the max norms $\big\|\frac{1}{\ell!} h^{\ell-1} \partial_x^\ell
h\big\|_\infty$, $1\le\ell\le2k+2$. We validate our estimates by comparing with
finite element solutions and present numerical evidence that suggests that even
when $h$ is real analytic and periodic, the expansion solution forms an
asymptotic series rather than a convergent series.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:05:42 GMT"
},
{
"version": "v2",
"created": "Wed, 9 Jun 2010 20:55:38 GMT"
}
] | 2010-06-11T00:00:00 | [
[
"Wilkening",
"Jon",
""
]
] |
0706.4104 | Benny Sudakov | Benny Sudakov and Van Vu | Local resilience of graphs | null | null | null | null | math.CO math.PR | null | In this paper, we initiate a systematic study of graph resilience. The
(local) resilience of a graph G with respect to a property P measures how much
one has to change G (locally) in order to destroy P. Estimating the resilience
leads to many new and challenging problems. Here we focus on random and
pseudo-random graphs and prove several sharp results.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:24:54 GMT"
},
{
"version": "v2",
"created": "Sat, 1 Dec 2007 16:39:54 GMT"
}
] | 2007-12-01T00:00:00 | [
[
"Sudakov",
"Benny",
""
],
[
"Vu",
"Van",
""
]
] |
0706.4105 | Peter Kleban | Jacob J. H. Simmons, Peter Kleban, and Robert M. Ziff | Exact factorization of correlation functions in 2-D critical percolation | 6 pages, 3 figures. Oral presentation given at STATPHYS 23. V2: Minor
additions and corrections, figures improved | Phys.Rev.E76:041106,2007 | 10.1103/PhysRevE.76.041106 | null | math-ph cond-mat.dis-nn cond-mat.stat-mech hep-th math.MP | null | By use of conformal field theory, we discover several exact factorizations of
higher-order density correlation functions in critical two-dimensional
percolation. Our formulas are valid in the upper half-plane, or any conformally
equivalent region. We find excellent agreement of our results with
high-precision computer simulations. There are indications that our formulas
hold more generally.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:47:16 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Sep 2007 18:57:36 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Simmons",
"Jacob J. H.",
""
],
[
"Kleban",
"Peter",
""
],
[
"Ziff",
"Robert M.",
""
]
] |
0706.4106 | Fuad Saradzhev | M. de Montigny, F.C. Khanna, F.M. Saradzhev | Path-integral quantization of Galilean Fermi fields | LATEX file, 27 pages, 8 figures; typos in the journal version are
removed, equation (1) in Introduction is corrected | Annals Phys.323:1191-1214,2008 | 10.1016/j.aop.2007.08.002 | null | hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Galilei-covariant fermionic field theories are quantized by using the
path-integral method and five-dimensional Lorentz-like covariant expressions of
non-relativistic field equations. Firstly, we review the five-dimensional
approach to the Galilean Dirac equation, which leads to the Levy-Leblond
equations, and define the Galilean generating functional and Green's functions
for positive- and negative-energy/mass solutions. Then, as an example of
interactions, we consider the quartic self-interacting potential ${\lambda}
(\bar{\Psi} {\Psi})^2$, and we derive expressions for the 2- and 4-point
Green's functions. Our results are compatible with those found in the
literature on non-relativistic many-body systems. The extended manifold allows
for compact expressions of the contributions in $(3+1)$ space-time. This is
particularly apparent when we represent the results with diagrams in the
extended $(4+1)$ manifold, since they usually encompass more diagrams in
Galilean $(3+1)$ space-time.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 21:50:37 GMT"
},
{
"version": "v2",
"created": "Tue, 2 Oct 2007 19:08:15 GMT"
},
{
"version": "v3",
"created": "Mon, 9 Feb 2015 19:00:25 GMT"
}
] | 2015-02-10T00:00:00 | [
[
"de Montigny",
"M.",
""
],
[
"Khanna",
"F. C.",
""
],
[
"Saradzhev",
"F. M.",
""
]
] |
0706.4107 | Mihai Patrascu | Gianni Franceschini, S. Muthukrishnan and Mihai Patrascu | Radix Sorting With No Extra Space | Full version of paper accepted to ESA 2007. (17 pages) | null | null | null | cs.DS | null | It is well known that n integers in the range [1,n^c] can be sorted in O(n)
time in the RAM model using radix sorting. More generally, integers in any
range [1,U] can be sorted in O(n sqrt{loglog n}) time. However, these
algorithms use O(n) words of extra memory. Is this necessary?
We present a simple, stable, integer sorting algorithm for words of size
O(log n), which works in O(n) time and uses only O(1) words of extra memory on
a RAM model. This is the integer sorting case most useful in practice. We
extend this result with same bounds to the case when the keys are read-only,
which is of theoretical interest. Another interesting question is the case of
arbitrary c. Here we present a black-box transformation from any RAM sorting
algorithm to a sorting algorithm which uses only O(1) extra space and has the
same running time. This settles the complexity of in-place sorting in terms of
the complexity of sorting.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:04:40 GMT"
}
] | 2007-06-29T00:00:00 | [
[
"Franceschini",
"Gianni",
""
],
[
"Muthukrishnan",
"S.",
""
],
[
"Patrascu",
"Mihai",
""
]
] |
0706.4108 | John Rice | Peter Bickel, Bas Kleijn, and John Rice | Event Weighted Tests for Detecting Periodicity in Photon Arrival Times | null | null | 10.1086/590399 | null | stat.ME astro-ph stat.AP | null | This paper treats the problem of detecting periodicity in a sequence of
photon arrival times, which occurs, for example, in attempting to detect
gamma-ray pulsars. A particular focus is on how auxiliary information,
typically source intensity, background intensity, and incidence angles and
energies associated with each photon arrival should be used to maximize the
detection power. We construct a class of likelihood-based tests, score tests,
which give rise to event weighting in a principled and natural way, and derive
expressions quantifying the power of the tests. These results can be used to
compare the efficacies of different weight functions, including cuts in energy
and incidence angle. The test is targeted toward a template for the periodic
lightcurve, and we quantify how deviation from that template affects the power
of detection.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:00:46 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bickel",
"Peter",
""
],
[
"Kleijn",
"Bas",
""
],
[
"Rice",
"John",
""
]
] |
0706.4109 | Seong-Gon Kim | Jeffery Houze, Sungho Kim, Seong-Gon Kim, S. C. Erwin and L. J.
Whitman | Structure of AlSb(001) and GaSb(001) Surfaces Under Extreme Sb-rich
Conditions | 6 pages, 6 figures | null | 10.1103/PhysRevB.76.205303 | null | cond-mat.mtrl-sci | null | We use density-functional theory to study the structure of AlSb(001) and
GaSb(001) surfaces. Based on a variety of reconstruction models, we construct
surface stability diagrams for AlSb and GaSb under different growth conditions.
For AlSb(001), the predictions are in excellent agreement with experimentally
observed reconstructions. For GaSb(001), we show that previously proposed model
accounts for the experimentally observed reconstructions under Ga-rich growth
conditions, but fails to explain the experimental observations under Sb-rich
conditions. We propose a new model that has a substantially lower surface
energy than all (nx5)-like reconstructions proposed previously and that, in
addition, leads to a simulated STM image in better agreement with experiment
than existing models. However, this new model has higher surface energy than
some of (4x3)-like reconstructions, models with periodicity that has not been
observed. Hence we conclude that the experimentally observed (1x5) and (2x5)
structures on GaSb(001) are kinetically limited rather than at the ground
state.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:04:40 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 19:32:21 GMT"
},
{
"version": "v3",
"created": "Fri, 29 Jun 2007 20:10:36 GMT"
},
{
"version": "v4",
"created": "Wed, 12 Sep 2007 19:47:38 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Houze",
"Jeffery",
""
],
[
"Kim",
"Sungho",
""
],
[
"Kim",
"Seong-Gon",
""
],
[
"Erwin",
"S. C.",
""
],
[
"Whitman",
"L. J.",
""
]
] |
0706.4110 | Emmanuel Sauvan | E. Sauvan (on behalf of the H1 Collaboration) | A General Search for New Phenomena at HERA | 4 pages, 3 figures; To appear in the proceedings of 15th
International Workshop on Deep Inelastic Scattering and Related Subjects (DIS
2007), Munich, Germany, 16-20 Apr 2007 | null | null | null | hep-ex | null | A model-independent search for deviations from the Standard Model prediction
is performed in $e^+ p$ and $e^- p$ collisions at HERA II using all high energy
data recorded by the H1 experiment. This corresponds to a total integrated
luminosity of 337 pb$^{-1}$. All event topologies involving isolated electrons,
photons, muons, neutrinos and jets with high transverse momenta are
investigated in a single analysis. Events are assigned to exclusive classes
according to their final state. A statistical algorithm is used to search for
deviations from the Standard Model in distributions of the scalar sum of
transverse momenta or invariant mass of final state particles and to quantify
their significance. A good agreement with the Standard Model prediction is
observed in most of the event classes. The most siginificant deviation is found
in the \mujnp channel in $e^+p$ collisions.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:04:48 GMT"
}
] | 2007-07-28T00:00:00 | [
[
"Sauvan",
"E.",
"",
"on behalf of the H1 Collaboration"
]
] |
0706.4111 | Cristina Bena | Cristina Bena | Effect of a single impurity on the local density of states in monolayer
and bilayer graphene | 8 pages, 3 figures, version accepted for publication | Phys. Rev. Lett. 100, 076601 (2008) | 10.1103/PhysRevLett.100.076601 | null | cond-mat.mes-hall | null | We use the T-matrix approximation to analyze the effect of a localized
impurity on the local density of states in mono- and bilayer graphene. For
monolayer graphene the Friedel oscillations generated by intranodal scattering
obey an inverse-square law, while the internodal ones obey an inverse law. In
the Fourier transform this translates into a filled circle of high intensity in
the center of the Brillouin zone, and empty circular contours around its
corners. For bilayer graphene both types of oscillations obey an inverse law.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:08:16 GMT"
},
{
"version": "v2",
"created": "Mon, 5 Nov 2007 11:26:37 GMT"
},
{
"version": "v3",
"created": "Thu, 21 Feb 2008 11:51:17 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bena",
"Cristina",
""
]
] |
0706.4112 | Jacob Fox | Jacob Fox, Benny Sudakov | Induced Ramsey-type theorems | 30 pages | null | null | null | math.CO | null | We present a unified approach to proving Ramsey-type theorems for graphs with
a forbidden induced subgraph which can be used to extend and improve the
earlier results of Rodl, Erdos-Hajnal, Promel-Rodl, Nikiforov, Chung-Graham,
and Luczak-Rodl. The proofs are based on a simple lemma (generalizing one by
Graham, Rodl, and Rucinski) that can be used as a replacement for Szemeredi's
regularity lemma, thereby giving much better bounds. The same approach can be
also used to show that pseudo-random graphs have strong induced Ramsey
properties. This leads to explicit constructions for upper bounds on various
induced Ramsey numbers.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:15:39 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Nov 2007 22:22:30 GMT"
},
{
"version": "v3",
"created": "Thu, 27 Dec 2007 21:18:10 GMT"
}
] | 2007-12-27T00:00:00 | [
[
"Fox",
"Jacob",
""
],
[
"Sudakov",
"Benny",
""
]
] |
0706.4113 | Yum-Tong Siu | Yum-Tong Siu | Effective Termination of Kohn's Algorithm for Subelliptic Multipliers | null | null | null | null | math.CV math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This note discusses the problem of the effective termination of Kohn's
algorithm for subelliptic multipliers for bounded smooth weakly pseudoconvex
domains of finite type. We give a complete proof for the case of special
domains of finite type and indicate briefly how this method is to be extended
to the case of general bounded smooth weakly pseudoconvex domains of finite
type.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 22:16:43 GMT"
},
{
"version": "v2",
"created": "Fri, 11 Jul 2008 23:04:07 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Aug 2008 02:13:30 GMT"
}
] | 2008-08-27T00:00:00 | [
[
"Siu",
"Yum-Tong",
""
]
] |
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