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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.3914 | Wellington G. Dantas | W.G. Dantas, M.J. de Oliveira, J.F.Stilck | Asymptotic behavior of the entropy of chains placed on stripes | null | null | 10.1103/PhysRevE.76.031133 | null | cond-mat.stat-mech | null | By using the transfer matrix approach, we investigate the asymptotic behavior
of the entropy of flexible chains with $M$ monomers each placed on stripes. In
the limit of high density of monomers, we study the behavior of the entropy as
a function of the density of monomers and the width of the stripe, inspired by
recent analytical studies of this problem for the particular case of dimers
(M=2). We obtain the entropy in the asymptotic regime of high densities for
chains with $M=2,..,9$ monomers, as well as for the special case of polymers,
where $M\to\infty$, and find that the results show a regular behavior similar
to the one found analytically for dimers. We also verify that in the
low-density limit the mean-field expression for the entropy is followed by the
results from our transfer matrix calculations.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:15:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dantas",
"W. G.",
""
],
[
"de Oliveira",
"M. J.",
""
],
[
"Stilck",
"J. F.",
""
]
] |
0706.3915 | Olivier Sarbach | F. S. Guzman, L. Lehner, O. Sarbach | Do unbounded bubbles ultimately become fenced inside a black hole? | 16 pages, 13 figures | Phys.Rev.D76:066003,2007 | 10.1103/PhysRevD.76.066003 | null | hep-th gr-qc | null | We examine the dynamical behavior of recently introduced bubbles in
asymptotically flat, five-dimensional spacetimes. Using numerical methods, we
find that even bubbles that initially start expanding eventually collapse to a
Schwarzschild-Tangherlini black hole.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:18:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Guzman",
"F. S.",
""
],
[
"Lehner",
"L.",
""
],
[
"Sarbach",
"O.",
""
]
] |
0706.3916 | Christopher Booth-Morrison | Chris Booth-Morrison, Jessica Weninger, Chantal K. Sudbrack, Zugang
Mao, Ronald D. Noebe, David N. Seidman | Effects of solute concentrations on kinetic pathways in Ni-Al-Cr alloys | Submitted to Acta Materialia, June, 2007 | null | null | null | cond-mat.mtrl-sci | null | The kinetic pathways resulting from the formation of coherent L12-ordered
y'-precipitates in the g-matrix (f.c.c.) of Ni-7.5 Al-8.5 Cr at.% and Ni-5.2
Al-14.2 Cr at.% alloys, aged at 873 K, are investigated by atom-probe
tomography (APT) over a range of aging times from 1/6 to 1024 hours; these
alloys have approximately the same volume fraction of the y'-precipitate phase.
Quantification of the phase decomposition within the framework of classical
nucleation theory reveals that the y-matrix solid-solution solute
supersaturations of both alloys provide the chemical driving force, which acts
as the primary determinant of the nucleation behavior. In the coarsening
regime, the temporal evolution of the y'-precipitate average radii and the
y-matrix supersaturations follow the predictions of classical coarsening
models, while the temporal evolution of the y'-precipitate number densities of
both alloys do not. APT results are compared to equilibrium calculations of the
pertinent solvus lines determined by employing both Thermo-Calc and
Grand-Canonical Monte Carlo simulation.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:13:45 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Booth-Morrison",
"Chris",
""
],
[
"Weninger",
"Jessica",
""
],
[
"Sudbrack",
"Chantal K.",
""
],
[
"Mao",
"Zugang",
""
],
[
"Noebe",
"Ronald D.",
""
],
[
"Seidman",
"David N.",
""
]
] |
0706.3917 | Brett Parker | Brett Parker | Holomorphic curves in Exploded Torus Fibrations: Compactness | 68 pages, 21 figures, v2: error in definition of `basic' corrected,
improved exposition | null | null | null | math.SG math.AP | null | The category of exploded torus fibrations is an extension of the category of
smooth manifolds in which some adiabatic limits look smooth. (For example, the
limits considered in tropical geometry appear smooth, also degenerations
corresponding to an algebraic family with normal crossing singularities are
smooth.) In this paper we prove a compactness theorem for (pseudo)-holomorphic
curves in exploded torus fibrations. In the case of smooth manifolds, this is
just a version of Gromov's compactness theorem in a topology strong enough for
gluing analysis.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:18:11 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jan 2008 17:02:00 GMT"
}
] | 2008-01-14T00:00:00 | [
[
"Parker",
"Brett",
""
]
] |
0706.3918 | Ken Dykema | Benoit Collins and Ken Dykema | A Linearization of Connes' Embedding Problem | 25pp | New York J. Math. 14 (2008), 617-641 | null | null | math.OA | null | We show that Connes' embedding problem for II_1-factors is equivalent to a
statement about distributions of sums of self-adjoint operators with matrix
coefficients. This is an application of a linearization result for finite von
Neumann algebras, which is proved using asymptotic second order freeness of
Gaussian random matrices.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:23:11 GMT"
}
] | 2012-02-28T00:00:00 | [
[
"Collins",
"Benoit",
""
],
[
"Dykema",
"Ken",
""
]
] |
0706.3919 | Michael Engelhardt | Michael Engelhardt (LHPC Collaboration) | Neutron electric polarizability from unquenched lattice QCD using the
background field approach | 36 pages, 11 figures. Note added concerning analytic continuation in
the external electric field; some notation made more precise | Phys.Rev.D76:114502,2007 | 10.1103/PhysRevD.76.114502 | null | hep-lat | null | A calculational scheme for obtaining the electric polarizability of the
neutron in lattice QCD with dynamical quarks is developed, using the background
field approach. The scheme differs substantially from methods previously used
in the quenched approximation, the physical reason being that the QCD ensemble
is no longer independent of the external electromagnetic field in the dynamical
quark case. One is led to compute (certain integrals over) four-point
functions. Particular emphasis is also placed on the physical role of constant
external gauge fields on a finite lattice; the presence of these fields
complicates the extraction of polarizabilities, since it gives rise to an
additional shift of the neutron mass unrelated to polarizability effects. The
method is tested on a SU(3) flavor-symmetric ensemble furnished by the MILC
Collaboration, corresponding to a pion mass of m_pi = 759 MeV. Disconnected
diagrams are evaluated using stochastic estimation. A small negative electric
polarizability of alpha =(-2.0 +/- 0.9) 10^(-4) fm^3 is found for the neutron
at this rather large pion mass; this result does not seem implausible in view
of the qualitative behavior of alpha as a function of m_pi suggested by Chiral
Effective Theory.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:25:38 GMT"
},
{
"version": "v2",
"created": "Sat, 1 Dec 2007 00:14:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Engelhardt",
"Michael",
"",
"LHPC Collaboration"
]
] |
0706.3920 | Alfred Hucht | A. Hucht, S. Buschmann and P. Entel | Molecular dynamics simulations of the dipolar-induced formation of
magnetic nanochains and nanorings | 6 pages, 6 figures | EPL 77, 57003 (2007) | 10.1209/0295-5075/77/57003 | null | cond-mat.mtrl-sci cond-mat.stat-mech | null | Iron, cobalt and nickel nanoparticles, grown in the gas phase, are known to
arrange in chains and bracelet-like rings due to the long-range dipolar
interaction between the ferromagnetic (or super-paramagnetic) particles. We
investigate the dynamics and thermodynamics of such magnetic dipolar
nanoparticles for low densities using molecular dynamics simulations and
analyze the influence of temperature and external magnetic fields on two- and
three-dimensional systems. The obtained phase diagrams can be understood by
using simple energetic arguments.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:14:58 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Hucht",
"A.",
""
],
[
"Buschmann",
"S.",
""
],
[
"Entel",
"P.",
""
]
] |
0706.3921 | Kaushik Bhattacharya | Alberto Bravo Garcia, Kaushik Bhattacharya, Sarira Sahu | The neutrino self-energy in a magnetized medium | 13 Pages, Latex file. Minor corrections included. To be published in
Modern Physics Letters A | Mod.Phys.Lett.A23:2771-2786,2008 | 10.1142/S0217732308028442 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this work we calculate the neutrino self-energy in presence of a
magnetized medium. The magnetized medium consists of electrons, positrons,
neutrinos and a uniform classical magnetic field. The calculation is done
assuming the background magnetic field is weak compared to the $W$-Boson mass
squared, as a consequence of which only linear order corrections in the field
are included in the $W$ boson propagator. The electron propagator consists all
order corrections in the background field. Although the neutrino self-energy in
a magnetized medium in various limiting cases has been calculated previously in
this article we produce the most general expression of the self-energy in
absence of the Landau quantization of the charged gauge fields. We calculate
the effect of the Landau quantization of the charged leptons on the neutrino
self-energy in the general case. Our calculation is specifically suited for
situations where the background plasma may be CP symmetric.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:11:38 GMT"
},
{
"version": "v2",
"created": "Fri, 20 Jul 2007 03:35:12 GMT"
},
{
"version": "v3",
"created": "Tue, 23 Sep 2008 08:52:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Garcia",
"Alberto Bravo",
""
],
[
"Bhattacharya",
"Kaushik",
""
],
[
"Sahu",
"Sarira",
""
]
] |
0706.3922 | Stephen Kuhlmann Ph.D. | A. Artikov, et al | CDF Central Preshower and Crack Detector Upgrade | 22 pages | null | null | ANL-HEP-PR-07-09 | physics.ins-det | null | The CDF Central Preshower and Crack Detector Upgrade consist of scintillator
tiles with embedded wavelength-shifting fibers, clear-fiber optical cables, and
multi-anode photomultiplier readout. A description of the detector design, test
results from R&D studies, and construction phase are reported. The upgrade was
installed late in 2004, and a large amount of proton-antiproton collider data
has been collected since then. Detector studies using those data are also
discussed.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:36:23 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Artikov",
"A.",
""
]
] |
0706.3923 | Suhasini Subba Rao | Jan Johannes and Suhasini Subba Rao | Nonparametric estimation for dependent data with an application to panel
time series | null | null | null | null | math.ST stat.TH | null | In this paper we consider nonparametric estimation for dependent data, where
the observations do not necessarily come from a linear process. We study
density estimation and also discuss associated problems in nonparametric
regression using the 2-mixing dependence measure. We compare the results under
2-mixing with those derived under the assumption that the process is linear. In
the context of panel time series where one observes data from several
individuals, it is often too strong to assume the joint linearity of processes.
Instead the methods developed in this paper enable us to quantify the
dependence through 2-mixing which allows for nonlinearity. We propose an
estimator of the panel mean function and obtain its rate of convergence. We
show that under certain conditions the rate of convergence can be improved by
allowing the number of individuals in the panel to increase with time.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:48:03 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Johannes",
"Jan",
""
],
[
"Rao",
"Suhasini Subba",
""
]
] |
0706.3924 | Agapi Emmanouilidou | Agapi Emmanouilidou | Total quadruple photoionization cross section of Beryllium in a
quasiclassical framework | null | null | null | null | physics.atom-ph | null | In a quasiclassical framework, we formulate the quadruple ionization by
single photon absorption of the Coulomb five-body problem. We present the
quadruple photoionization total cross section of the ground state of Beryllium
for energies up to 620 eV. Our quasiclassical results for energies close to
threshold are in agreement with the Wannier threshold law for four electron
escape. In addition, the agreement of our results with a shape formula provides
support for the overall shape of our total quadruple cross section. Finally, we
find that the photon energy where the maximum of the total photoionization
cross section occurs for single, double, triple and quadruple photoionization
of H, He, Li and Be, respectively, seems to follow a linear relation with the
threshold energy for complete break-up of the respective element.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:39:28 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Emmanouilidou",
"Agapi",
""
]
] |
0706.3925 | Alex Bernardini | Alex E. Bernardini, Marcelo M. Guzzo | Influence of second-order corrections to the energy-dependence of
neutrino flavor conversion formulae | 13 pages, 3 figures | Mod. Phys. Lett. A23 (2008) 1949-1960 | 10.1142/S0217732308026066 | null | hep-ph | null | We discuss the {\em intermediate} wave-packet formalism for analytically
quantifying the energy dependence of the two-flavor conversion formula that is
usually considered for analyzing neutrino oscillations and adjusting the
focusing horn, target position and/or detector location of some flavor
conversion experiments. Following a sequence of analytical approximations where
we consider the second-order corrections in a power series expansion of the
energy, we point out a {\em residual} time-dependent phase which, in addition
to some well known wave-packet effects, can subtly modify the oscillation
parameters and limits. In the present precision era of neutrino oscillation
experiments where higher precision measurements are required, we quantify some
small corrections in neutrino flavor conversion formulae which lead to a
modified energy-dependence for $\nu_{\mu}\leftrightarrow\nu_{e}$ oscillations.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:44:00 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 11:35:20 GMT"
}
] | 2009-11-10T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
],
[
"Guzzo",
"Marcelo M.",
""
]
] |
0706.3926 | Alex Bernardini | Alex E. Bernardini, Marcelo M. Guzzo | Theoretical correlation between possible evidences of neutrino chiral
oscillations and polarization measurements | 12 pages, 2 figures | Mod. Phys. Lett. A23 (2008) 1141-1150 | 10.1142/S0217732308025723 | null | hep-ph | null | Reporting about the formalism with the Dirac equation we describe the
dynamics of chiral oscillations for a fermionic particle non-minimally coupling
with an external magnetic field. For massive particles, the chirality and
helicity quantum numbers represent different physical quantities of
representative importance in the study of chiral interactions, in particular,
in the context of neutrino physics. After solving the interacting Hamiltonian
(Dirac) equation for the corresponding {\em fermionic} Dirac-{\em type}
particle (neutrino) and quantifying chiral oscillations in the Dirac wave
packet framework, we avail the possibility of determining realistic neutrino
chirality conversion rates by means of (helicity) polarization measurements. We
notice that it can become feasible for some particular magnetic field
configurations with large values of {\boldmath$B$} orthogonal to the direction
of the propagating particle.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 21:48:33 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 11:39:22 GMT"
}
] | 2009-11-10T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
],
[
"Guzzo",
"Marcelo M.",
""
]
] |
0706.3927 | Hans-Jakob Grimm | H.-J. Grimm, J. McDowell, A. Zezas, D.-W. Kim, G. Fabbiano | The X-ray binary population in M33: II. X-ray spectra and variability | 25 pages, ApJ accepted | null | 10.1086/519952 | null | astro-ph | null | In this paper we investigate the X-ray spectra and X-ray spectral variability
of compact X-ray sources for 3 Chandra observations of the Local Group galaxy
M33. The observations are centered on the nucleus and the star forming region
NGC 604. In the observations 261 sources have been detected. For a total of 43
sources the number of net counts is above 100, sufficient for a more detailed
spectral fitting. Of these sources, 25 have been observed in more than one
observation, allowing the study of spectral variability on ~months timescales.
A quarter of the sources are found to be variable between observations.
However, except for two foreground sources, no source is variable within any
observation above the 99% confidence level. Only six sources show significant
spectral variability between observations. A comparison of N_H values with HI
observations shows that X-ray absorption values are consistent with Galactic
X-ray binaries and most sources in M33 are intrinsically absorbed. The pattern
of variability and the spectral parameters of these sources are consistent with
the M33 X-ray source population being dominated by X-ray binaries: Two thirds
of the 43 bright sources have spectral and timing properties consistent with
X-ray binaries; we also find two candidates for super-soft sources and two
candidates for quasi-soft sources.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 18:47:35 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Grimm",
"H. -J.",
""
],
[
"McDowell",
"J.",
""
],
[
"Zezas",
"A.",
""
],
[
"Kim",
"D. -W.",
""
],
[
"Fabbiano",
"G.",
""
]
] |
0706.3928 | Alex Bernardini | Alex E. Bernardini | Small Corrections to the Tunneling Phase Time Formulation | 14 pages, 3 figures | Eur.Phys.J.C49:891-896,2007 | 10.1140/epjc/s10052-006-0132-3 | null | hep-ph | null | After reexamining the above barrier diffusion problem where we notice that
the wave packet collision implies the existence of {\em multiple} reflected and
transmitted wave packets, we analyze the way of obtaining phase times for
tunneling/reflecting particles in a particular colliding configuration where
the idea of multiple peak decomposition is recovered. To partially overcome the
analytical incongruities which frequently rise up when the stationary phase
method is adopted for computing the (tunneling) phase time expressions, we
present a theoretical exercise involving a symmetrical collision between two
identical wave packets and a unidimensional squared potential barrier where the
scattered wave packets can be recomposed by summing the amplitudes of
simultaneously reflected and transmitted wave components so that the conditions
for applying the stationary phase principle are totally recovered. Lessons
concerning the use of the stationary phase method are drawn.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:01:19 GMT"
}
] | 2010-10-27T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
]
] |
0706.3929 | Alex Bernardini | Alex E. Bernardini | The Exact Correspondence between Phase Times and Dwell Times in a
Symmetrical Quantum Tunneling Configuration | 11 pages, 2 figures | Eur. Phys. J. C53 (2008) 673-678 | 10.1140/epjc/s10052-007-0476-3 | null | quant-ph | null | The general and explicit relation between the phase time and the dwell time
for quantum tunneling or scattering is investigated. Considering a symmetrical
collision of two identical wave packets with an one-dimensional barrier, here
we demonstrate that these two distinct transit time definitions give connected
results where, however, the phase time (group delay) accurately describes the
exact position of the scattered particles. The analytical difficulties that
arise when the stationary phase method is employed for obtaining phase
(traversal) times are all overcome. Multiple wave packet decomposition allows
us to recover the exact position of the reflected and transmitted waves in
terms of the phase time, which, in addition to the exact relation between the
phase time and the dwell time, leads to right interpretation for both of them.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:09:52 GMT"
},
{
"version": "v2",
"created": "Thu, 29 Nov 2007 11:46:06 GMT"
}
] | 2009-11-10T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
]
] |
0706.3930 | Alex Bernardini | Alex E. Bernardini | Relativistic tunneling and accelerated transmission | 10 pages, 1 figure | J. Phys. A41 (2008) 215302 | 10.1088/1751-8113/41/21/215302 | null | quant-ph | null | We obtain the solutions for the tunneling zone of a one-dimensional
electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave
equation regime when the incoming wave packet exhibits the possibility of being
almost totally transmitted through the potential barrier. The conditions for
the occurrence of accelerated and, eventually, superluminal tunneling
transmission probabilities are all quantified and the problematic superluminal
interpretation originated from the study based on non-relativistic dynamics of
tunneling is overcome. The treatment of the problem suggests revealing insights
into condensed-matter experiments using electrostatic barriers in single- and
bi-layer graphene, for which the accelerated tunneling effect deserves a more
careful investigation.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:18:06 GMT"
},
{
"version": "v2",
"created": "Wed, 30 Jan 2008 10:46:34 GMT"
},
{
"version": "v3",
"created": "Sun, 20 Apr 2008 19:00:18 GMT"
}
] | 2009-11-10T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
]
] |
0706.3931 | Alex Bernardini | Alex E. Bernardini | The coupling constants for an electroweak model with a $SU(4)_{PS}
\otimes SU(4)_{EW}$ unification symmetry | 8 pages | Commun. Theor. Phys. 47 (2007) 879-883 | 10.1088/0253-6102/47/5/022 | null | hep-ph | null | We introduce the sequence of spontaneous symmetry breaking of a coupling
between Pati-Salam and electroweak symmetries $SU(4)_{PS} \otimes SU(4)_{EW}$
in order to establish a mathematically consistent relation among the coupling
constants at grand unification energy scale. With the values of baryon minus
lepton quantum numbers of known quarks and leptons, by including right-handed
neutrinos, we can find the mixing angle relations at different energy levels up
to the electromagnetic $U(1)_{EM}$ scale.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:18:55 GMT"
}
] | 2009-11-10T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
]
] |
0706.3932 | Alex Bernardini | Alex E. Bernardini | Dirac neutrino mass from the beta decay end-point modified by the
dynamics of a Lorentz-violating equation of motion | 11 pages, 4 figures | Phys.Rev.D75:097901,2007 | 10.1103/PhysRevD.75.097901 | null | hep-ph | null | Using a generalized procedure for obtaining the equation of motion of a
propagating fermionic particle, we examine previous claims for a lightlike
preferred axis embedded in the framework of Lorentz-invariance violation with
preserved algebra. In a high energy scale, the corresponding equation of motion
is reduced to a conserving lepton number chiral (VSR) equation, and in a low
energy scale, the Dirac equation for a free is recovered. The new dynamics
introduces some novel ingredients (modified cross section) to the phenomenology
of the tritium beta decay end-point.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:25:20 GMT"
},
{
"version": "v2",
"created": "Fri, 25 Jan 2008 15:53:22 GMT"
}
] | 2011-07-19T00:00:00 | [
[
"Bernardini",
"Alex E.",
""
]
] |
0706.3933 | Eitan Ehrenfreund | E. Ehrenfreund, C. Lungenschmied, G. Dennler, H. Neugebauer, N. S.
Sariciftci | Negative capacitance in organic semiconductor devices: bipolar injection
and charge recombination mechanism | 3 pages, 3 figures, accepted for publication in Applied Physics
Letters | Applied Physics Letters, Vol. 91, 012112 (2007) | 10.1063/1.2752024 | null | physics.chem-ph | null | We report negative capacitance at low frequencies in organic semiconductor
based diodes and show that it appears only under bipolar injection conditions.
We account quantitatively for this phenomenon by the recombination current due
to electron-hole annihilation. Simple addition of the recombination current to
the well established model of space charge limited current in the presence of
traps, yields excellent fits to the experimentally measured admittance data.
The dependence of the extracted characteristic recombination time on the bias
voltage is indicative of a recombination process which is mediated by localized
traps.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 22:38:30 GMT"
}
] | 2007-07-07T00:00:00 | [
[
"Ehrenfreund",
"E.",
""
],
[
"Lungenschmied",
"C.",
""
],
[
"Dennler",
"G.",
""
],
[
"Neugebauer",
"H.",
""
],
[
"Sariciftci",
"N. S.",
""
]
] |
0706.3934 | Edward Anderson | Edward Anderson | Foundations of Relational Particle Dynamics | Minor typos corrected; references updated | Class.Quant.Grav.25:025003,2008 | 10.1088/0264-9381/25/2/025003 | null | gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Relational particle dynamics include the dynamics of pure shape and cases in
which absolute scale or absolute rotation are additionally meaningful. These
are interesting as regards the absolute versus relative motion debate as well
as discussion of conceptual issues connected with the problem of time in
quantum gravity. In spatial dimension 1 and 2 the relative configuration spaces
of shapes are n-spheres and complex projective spaces, from which knowledge I
construct natural mechanics on these spaces. I also show that these coincide
with Barbour's indirectly-constructed relational dynamics by performing a full
reduction on the latter. Then the identification of the configuration spaces as
n-spheres and complex projective spaces, for which spaces much mathematics is
available, significantly advances the understanding of Barbour's relational
theory in spatial dimensions 1 and 2. I also provide the parallel study of a
new theory for which positon and scale are purely relative but orientation is
absolute. The configuration space for this is an n-sphere regardless of the
spatial dimension, which renders this theory a more tractable arena for
investigation of implications of scale invariance than Barbour's theory itself.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:01:18 GMT"
},
{
"version": "v2",
"created": "Mon, 15 Oct 2007 00:20:29 GMT"
},
{
"version": "v3",
"created": "Fri, 2 Nov 2007 12:53:02 GMT"
},
{
"version": "v4",
"created": "Sun, 8 Nov 2009 23:50:57 GMT"
}
] | 2009-11-09T00:00:00 | [
[
"Anderson",
"Edward",
""
]
] |
0706.3935 | Andrea M. Gilbert | Andrea M. Gilbert and James R. Graham | Feedback in the Antennae Galaxies (NGC 4038/9): I. High-Resolution
Infrared Spectroscopy of Winds from Super Star Clusters | Accepted to ApJ | null | 10.1086/520910 | UCRL-JRNL-231642 | astro-ph | null | We present high-resolution (R ~ 24,600) near-IR spectroscopy of the youngest
super star clusters (SSCs) in the prototypical starburst merger, the Antennae
Galaxies. These SSCs are young (3-7 Myr old) and massive (10^5 - 10^7 M_sun for
a Kroupa IMF) and their spectra are characterized by broad, extended Br-gamma
emission, so we refer to them as emission-line clusters (ELCs) to distinguish
them from older SSCs. The Brgamma lines of most ELCs have supersonic widths
(60-110 km/s FWHM) and non-Gaussian wings whose velocities exceed the clusters'
escape velocities. This high-velocity unbound gas is flowing out in winds that
are powered by the clusters' massive O and W-R stars over the course of at
least several crossing times. The large sizes of some ELCs relative to those of
older SSCs may be due to expansion caused by these outflows; many of the ELCs
may not survive as bound stellar systems, but rather dissipate rapidly into the
field population. The observed tendency of older ELCs to be more compact than
young ones is consistent with the preferential survival of the most
concentrated clusters at a given age.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:08:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gilbert",
"Andrea M.",
""
],
[
"Graham",
"James R.",
""
]
] |
0706.3936 | Davide Fioravanti | Davide Fioravanti and Marco Rossi | On the commuting charges for the highest dimension SU(2) operators in
planar ${\cal N}=4$ SYM | Latex file, 20 pages, some typos corrected, some technical details
expanded and explained | JHEP0708:089,2007 | 10.1088/1126-6708/2007/08/089 | null | hep-th | null | We consider the highest anomalous dimension operator in the SU(2) sector of
planar ${\cal N}=4$ SYM at all-loop, though neglecting wrapping contributions.
In any case, the latter enter the loop expansion only after a precise
length-depending order. In the thermodynamic limit we write both a linear
integral equation for the Bethe root density and a linear system obeyed by the
commuting charges. Consequently, we determine the leading strong coupling
contribution to the density and from this an approximation to the leading and
sub-leading terms of any charge $Q_r$: it scales as $\lambda ^{1/4-r/2}$, which
generalises the Gubser-Klebanov-Polyakov energy law. In the end, we briefly
extend these considerations to finite lengths and 'excited' operators by using
the idea of a non-linear integral equation.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:24:13 GMT"
},
{
"version": "v2",
"created": "Fri, 13 Jul 2007 21:01:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Fioravanti",
"Davide",
""
],
[
"Rossi",
"Marco",
""
]
] |
0706.3937 | Jerzy Dydak | N.Brodskiy, J.Dydak, B.Labuz, A.Mitra | Rips complexes and covers in the uniform category | 26 pages. The paper was split and the second part is available at
arXiv:0802.4304 | null | null | null | math.MG math.GN | null | James \cite{Jam} introduced uniform covering maps as an analog of covering
maps in the topological category. Subsequently Berestovskii and Plaut
\cite{BP3} introduced a theory of covers for uniform spaces generalizing their
results for topological groups \cite{BP1}-\cite{BP2}. Their main concepts are
discrete actions and pro-discrete actions, respectively. In case of
pro-discrete actions Berestovskii and Plaut provided an analog of the universal
covering space and their theory works well for the so-called coverable spaces.
As will be seen in Section \ref{SECTION-Comparison}, \cite{BP3} generalizes
only regular covering maps in topology and pro-discrete actions may not be
preserved by compositions.
In this paper we redefine the uniform covering maps and we generalize
pro-discrete actions using Rips complexes and the chain lifting property. We
expand the concept of generalized paths of Krasinkiewicz and Minc
\cite{KraMin}.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:39:00 GMT"
},
{
"version": "v2",
"created": "Sun, 23 Sep 2007 21:05:55 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Mar 2008 13:36:16 GMT"
}
] | 2008-03-03T00:00:00 | [
[
"Brodskiy",
"N.",
""
],
[
"Dydak",
"J.",
""
],
[
"Labuz",
"B.",
""
],
[
"Mitra",
"A.",
""
]
] |
0706.3938 | Ted K. Wyder | Ted K. Wyder (1), D. Christopher Martin (1), David Schiminovich (2),
Mark Seibert (3), Tamas Budavari (4), Marie A. Treyer (1,5), Tom A. Barlow
(1), Karl Forster (1), Peter G. Friedman (1), Patrick Morrissey (1), Susan G.
Neff (6), Todd Small (1), Luciana Bianchi (4), Jose Donas (5), Timothy M.
Heckman (4), Young-Wook Lee (7), Barry F. Madore (3), Bruno Milliard (5), R.
Michael Rich (8), Alex S. Szalay (4), Barry Y. Welsh (9), Sukyoung K. Yi (7)
((1) Caltech, (2) Columbia University, (3) Carnegie Institution of
Washington, (4) Johns Hopkins University, (5) Laboratoire d'Astrophysique de
Marseille, (6) NASA Goddard Space Flight Center, (7) Yonsei University, (8)
University of California Los Angeles, (9) University of California Berkeley) | The UV-optical Galaxy Color-Magnitude Diagram I: Basic Properties | 64 pages, 27 figures, accepted for publication in the ApJS GALEX
special issue | Astrophys.J.Suppl.173:293-314,2007 | 10.1086/521402 | null | astro-ph | null | We have analyzed the bivariate distribution of galaxies as a function of
ultraviolet-optical colors and absolute magnitudes in the local universe. The
sample consists of galaxies with redshifts and optical photometry from the
Sloan Digital Sky Survey (SDSS) main galaxy sample matched with detections in
the near-ultraviolet (NUV) and far-ultraviolet (FUV) bands in the Medium
Imaging Survey being carried out by the Galaxy Evolution Explorer (GALEX)
satellite. In the (NUV-r)_{0.1} vs. M_{r,0.1} galaxy color-magnitude diagram,
the galaxies separate into two well-defined blue and red sequences. The
(NUV-r)_{0.1} color distribution at each M_{r,0.1} is not well fit by the sum
of two Gaussians due to an excess of galaxies in between the two sequences. The
peaks of both sequences become redder with increasing luminosity with a
distinct blue peak visible up to M_{r,0.1}\sim-23. The r_{0.1}-band luminosity
functions vary systematically with color, with the faint end slope and
characteristic luminosity gradually increasing with color. After correcting for
attenuation due to dust, we find that approximately one quarter of the color
variation along the blue sequence is due to dust with the remainder due to star
formation history and metallicity. Finally, we present the distribution of
galaxies as a function of specific star formation rate and stellar mass. The
specific star formation rates imply that galaxies along the blue sequence
progress from low mass galaxies with star formation rates that increase
somewhat with time to more massive galaxies with a more or less constant star
formation rate. Above a stellar mass of ~10^10.5 M_{sun}, galaxies with low
ratios of current to past averaged star formation rate begin to dominate.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:52:46 GMT"
}
] | 2009-12-15T00:00:00 | [
[
"Wyder",
"Ted K.",
""
],
[
"Martin",
"D. Christopher",
""
],
[
"Schiminovich",
"David",
""
],
[
"Seibert",
"Mark",
""
],
[
"Budavari",
"Tamas",
""
],
[
"Treyer",
"Marie A.",
""
],
[
"Barlow",
"Tom A.",
""
],
[
"Forster",
"Karl",
""
],
[
"Friedman",
"Peter G.",
""
],
[
"Morrissey",
"Patrick",
""
],
[
"Neff",
"Susan G.",
""
],
[
"Small",
"Todd",
""
],
[
"Bianchi",
"Luciana",
""
],
[
"Donas",
"Jose",
""
],
[
"Heckman",
"Timothy M.",
""
],
[
"Lee",
"Young-Wook",
""
],
[
"Madore",
"Barry F.",
""
],
[
"Milliard",
"Bruno",
""
],
[
"Rich",
"R. Michael",
""
],
[
"Szalay",
"Alex S.",
""
],
[
"Welsh",
"Barry Y.",
""
],
[
"Yi",
"Sukyoung K.",
""
]
] |
0706.3939 | Michael Ramsey-Musolf | Michael J. Ramsey-Musolf | Future Directions in Parity Violation: From Quarks to the Cosmos | Talk given at PAVI 06 workshop on parity-violating interactions,
Milos, Greece (May, 2006); 10 pages | Eur.Phys.J.A32:379-388,2007 | 10.1140/epja/i2006-10413-1 | null | nucl-th | null | I discuss the prospects for future studies of parity-violating (PV)
interactions at low energies and the insights they might provide about open
questions in the Standard Model as well as physics that lies beyond it. I cover
four types of parity-violating observables: PV electron scattering; PV hadronic
interactions; PV correlations in weak decays; and searches for the permanent
electric dipole moments of quantum systems.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:53:48 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ramsey-Musolf",
"Michael J.",
""
]
] |
0706.3940 | David Nitz | D. Nitz (for the Pierre Auger Collaboration) | The Northern Site of the Pierre Auger Observatory | Submission to the 30th International Cosmic Ray Conference, Merida
Mexico, July 2007; 4 pages, 4 figures | null | null | null | astro-ph | null | The Pierre Auger Observatory is a multi-national project for research on
ultra-high energy cosmic rays. The Southern Auger Observatory in Mendoza
province, Argentina, is approaching completion in 2007 with an instrumented
area of 3,000 km^2. It will accurately measure the spectrum and composition of
ultra-high energy cosmic rays up to and beyond the predicted GZK feature. We
are obtaining results on the energy spectrum, mass composition and distribution
of arrival directions on the southern sky. The Northern Auger Observatory is
designed to complete and extend the investigations begun in the South. It will
establish charged particle astronomy and thus open a new window into the
universe. The distribution of arrival directions of the highest energy events
will point the way to unveiling the almost century old mystery of the origin
and nature of ultra-high energy cosmic rays. Achieving this goal requires
collecting many more events in spite of the steeply falling energy spectrum.
The planned northern site will have an instrumented area of 4,000 square miles
(10,370 km}^2 in Southeast Colorado, USA. The paper covers the science of
charged particle astronomy, the layout and the technical implementation of the
Northern Auger Observatory.
| [
{
"version": "v1",
"created": "Tue, 26 Jun 2007 23:55:10 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Nitz",
"D.",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.3941 | Zuhui Fan | Z.H. Fan | Intrinsic alignments of galaxies and their effects on weak lensing
detections of mass concentrations | ApJ in press | null | 10.1086/521182 | null | astro-ph | null | In this paper we investigate the influence of the intrinsic alignment of
background galaxies on weak lensing detections of mass concentrations.
Specifically, we analyze the number counts of false peaks resulting from
intrinsic ellipticities in lensing convergence maps. Including the alignment of
source galaxies, the full noise variance from intrinsic ellipticites in
convergence $\kappa$-maps can be written as
$\sigma^2_0=\sigma^2_{0ran}+\sigma^2_{0corr}$, where $\sigma^2_{0ran}$ is the
noise contributed from randomly oriented source galaxies and $\sigma^2_{0corr}$
denotes the additional noise from intrinsic alignments. However, it is
observationally difficult to measure $\sigma^2_{0corr}$ and usually only
$\sigma^2_{0ran}$ can be estimated in weak lensing observations. Thus the
observational signal-to-noise ratio is often defined with respect to
$\sigma_{0ran}$, which is denoted as $\nu_{ran}$ in this paper. The true
signal-to-noise ratio $\nu$ in terms of $\sigma_0$ is then
$\nu=\nu_{ran}/(1+\sigma^2_{0corr}/\sigma^2_{0ran})^{1/2}$. Given a detection
threshold on $\nu_{ran}$, a larger value of $\sigma^2_{0corr}/\sigma^2_{0ran}$
leads to a lower threshold on $\nu$ and therefore a larger expected number of
false peaks. With $\sigma^2_{0corr}/\sigma^2_{0ran}\sim 10%$, the average
number of false peaks with $\nu_{ran}\ge 3.5$ nearly doubles compared to that
without considering the alignment, and for $\nu_{ran}\ge 5$, the number is
tripled. As a result, the efficiency of weak lensing cluster detection degrades
significantly. (Abridged)
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 00:04:55 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fan",
"Z. H.",
""
]
] |
0706.3942 | Michael Ramsey-Musolf | Michael J. Ramsey-Musolf | Chiral Symmetries and Low Energy Searches for New Physics | Talk given at 5th International Workshop on Chiral Dynamics,
Durham/Chapel Hill, NC (September, 2006); 12 pages | null | 10.1142/9789812790804_0007 | null | nucl-th | null | I discuss low energy searches for new physics beyond the Standard Model,
identifying the role played by chiral symmetries in these searches and in
various new physics scenarios. I focus in particular on electric dipole moment
searches; precision studies of weak decays and electron scattering; and
neutrino properties and interactions.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 00:08:21 GMT"
}
] | 2017-08-23T00:00:00 | [
[
"Ramsey-Musolf",
"Michael J.",
""
]
] |
0706.3943 | Michele Cantiello | Cantiello, Michele (1,2), Blakeslee, John P.(1), Raimondo, Gabriella
(2) ((1) Department of Physics and Astronomy, Washington State University,
Pullman, WA; (2)INAF--Osservatorio Astronomico di Teramo, Italy) | The globular cluster system in NGC5866: optical observations from HST
Advanced Camera for Surveys | ApJ, accepted | null | 10.1086/521218 | null | astro-ph | null | We perform a detailed study of the Globular Cluster (GC) system in the galaxy
NGC5866 based on F435W, F555W, and F625W (~ B, V, and R) HST Advanced Camera
for Surveys images.
Adopting color, size and shape selection criteria, the final list of GC
candidates comprises 109 objects, with small estimated contamination from
background galaxies, and foreground stars.
The color distribution of the final GC sample has a bimodal form. Adopting
color to metallicity transformations derived from the Teramo--SPoT simple
stellar population model, we estimate a metallicity [Fe/H]~ -1.5, and -0.6 dex
for the blue and red peaks, respectively. A similar result is found if the
empirical color-metallicity relations derived from Galactic GCs data are used.
The two subpopulations show some of the features commonly observed in the GC
system of other galaxies, like a ``blue tilt'', higher central concentrations
of the red subsystem, and larger half--light radii at larger galactocentric
distances. However, we do not find evidence of a substantial difference between
the average sizes of red and blue clusters.
Our analysis of the GC Luminosity Function indicates a V-band Turn-Over
Magnitude V$_0^{TOM}$=23.46+-0.06, or M$_{V,0}^{TOM}\sim-7.29 +- 0.10$ mag,
using the distance modulus derived from the average of SBF and the PNLF
distances. The absolute Turn-Over Magnitude obtained agrees well with
calibrations from literature. The specific frequency is measured to be $S_N=1.4
+- 0.3$, typical for galaxies of this type.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 00:16:20 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Cantiello",
"",
""
],
[
"Michele",
"",
""
],
[
"Blakeslee",
"",
""
],
[
"P.",
"John",
""
],
[
"Raimondo",
"",
""
],
[
"Gabriella",
"",
""
]
] |
0706.3944 | Kunihiko Terasaki | Kunihiko Terasaki | A new tetra-quark interpretation of X(3872) | 4 pages, 0 figures, RevTeX, description clarified | Prog. Theor. Phys. 118: 821-826, 2007 | 10.1143/PTP.118.821 | YITP-07-36, KANAZAWA-0707 | hep-ph hep-ex nucl-th | null | A new tetra-quark interpretation of X(3872) is presented. In this model,
X(3872) consists of two degenerate tetra-quark mesons, {[cn](cbar nbar) +-
(cn)[cbar nbar]}_{I=0}, and, therefore, it is naturally understood that X(3872)
decays into two different eigenstates of G-parity.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 02:01:38 GMT"
},
{
"version": "v2",
"created": "Mon, 9 Jul 2007 02:26:30 GMT"
},
{
"version": "v3",
"created": "Mon, 12 Nov 2007 01:08:20 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Terasaki",
"Kunihiko",
""
]
] |
0706.3945 | Irina Novikova | Irina Novikova, David F. Phillips, and Ronald L. Walsworth | Slow light with integrated gain and large pulse delay | 5 pages, 4 figures; abstract is shortened, some typo corrected | Phys. Rev. Lett. 99, 173604 (2007). | 10.1103/PhysRevLett.99.173604 | null | physics.optics physics.atom-ph quant-ph | null | We demonstrate slow and stored light in Rb vapor with a combination of
desirable features: minimal loss and distortion of the pulse shape, and large
fractional delay (> 10). This behavior is enabled by: (i) a group index that
can be controllably varied during light pulse propagation; and (ii)
controllable gain integrated into the medium to compensate for pulse loss. Any
medium with the above two characteristics should be able to realize similarly
high-performance slow light.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 02:42:18 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 19:37:47 GMT"
},
{
"version": "v3",
"created": "Mon, 2 Jul 2007 04:05:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Novikova",
"Irina",
""
],
[
"Phillips",
"David F.",
""
],
[
"Walsworth",
"Ronald L.",
""
]
] |
0706.3946 | Jongchul Mun | Jongchul Mun, Patrick Medley, Gretchen K. Campbell, Luis G. Marcassa,
David E. Pritchard, Wolfgang Ketterle | Phase diagram for a Bose-Einstein condensate moving in an optical
lattice | 4 figures | null | 10.1103/PhysRevLett.99.150604 | null | cond-mat.other | null | The stability of superfluid currents in a system of ultracold bosons was
studied using a moving optical lattice. Superfluid currents in a very weak
lattice become unstable when their momentum exceeds 0.5 recoil momentum.
Superfluidity vanishes already for zero momentum as the lattice deep reaches
the Mott insulator(MI) phase transition. We study the phase diagram for the
disappearance of superfluidity as a function of momentum and lattice depth
between these two limits. Our phase boundary extrapolates to the critical
lattice depth for the superfluid-to-MI transition with 2% precision. When a
one-dimensional gas was loaded into a moving optical lattice a sudden
broadening of the transition between stable and unstable phases was observed.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:42:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mun",
"Jongchul",
""
],
[
"Medley",
"Patrick",
""
],
[
"Campbell",
"Gretchen K.",
""
],
[
"Marcassa",
"Luis G.",
""
],
[
"Pritchard",
"David E.",
""
],
[
"Ketterle",
"Wolfgang",
""
]
] |
0706.3947 | Arlin Crotts | Arlin P.S. Crotts | Transient Lunar Phenomena: Regularity and Reality | 45 pages, 1 figure, submitted to ApJ. Other papers in series found at
http://www.astro.columbia.edu/~arlin/TLP/ | null | null | null | astro-ph | null | Transient lunar phenomena (TLPs) have been reported for centuries, but their
nature is largely unsettled. A review of TLP reports shows regularities in the
observations; a key question is whether this structure is imposed by human
observer effects, terrestrial atmospheric effects or processes tied to the
lunar surface. I interrogate an extensive TLP catalog to determine if human
factors determine the distribution of TLP reports. I divide the sample
according to variables which should produce varying results if determining
factors involve humans e.g., historical epoch or geographical location of the
observer, not reflecting phenomena tied to the lunar surface. Regardless of how
we split the ample, the results are similar: ~50% of the reports involve crater
Aristarchus nd vicinity, ~16% from Plato, ~6% from other recent, major impacts,
plus a few at Grimaldi. Mare Crisium produces a robust signal for three of five
averages of up to 7% of the reports (however, Crisium is an extended feature).
The consistency in TLP report counts for specific features indicates that >~80%
of reports are consistent with being real (perhaps excepting Crisium). Some
commonly reported sites disappear from the robust averages, including
Alphonsus, Ross D and Gassendi. TLP reports supporting these sites originate
almost entirely after year 1955, when TLPs became more popular targets of
observation and many more (and inexperienced) observers searched for TLPs. In a
companion paper, we compare the spatial distribution of robust TLP sites of
transient outgassing (seen on Apollo and Lunar Prospector). To a high
confidence against the random hypothesis, robust TLP sites and those of lunar
outgassing correlate strongly, further arguing for the reality of TLPs.
[Abstract abridged.]
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:20:38 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Crotts",
"Arlin P. S.",
""
]
] |
0706.3948 | Kensuke Inaba | Kensuke Inaba and Akihisa Koga | Metal-insulator transition in the two-orbital Hubbard model at
fractional band fillings: Self-energy functional approach | 7 pages, 10 figures | null | 10.1143/JPSJ.76.094712 | null | cond-mat.str-el | null | We investigate the infinite-dimensional two-orbital Hubbard model at
arbitrary band fillings. By means of the self-energy functional approach, we
discuss the stability of the metallic state in the systems with same and
different bandwidths. It is found that the Mott insulating phases are realized
at commensurate band fillings. Furthermore, it is clarified that the orbital
selective Mott phase with one orbital localized and the other itinerant is
stabilized even at fractional band fillings in the system with different
bandwidths.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:26:07 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Inaba",
"Kensuke",
""
],
[
"Koga",
"Akihisa",
""
]
] |
0706.3949 | Arlin Crotts | Arlin P.S. Crotts | Lunar Outgassing, Transient Phenomena and The Return to The Moon, I:
Existing Data | 35 pages, 3 figures, submitted to Icarus. Other papers in series
found at http://www.astro.columbia.edu/~arlin/TLP/ | null | 10.1086/591634 | null | astro-ph | null | Herein the transient lunar phenomena (TLP) report database is subjected to a
discriminating statistical filter robust against sites of spurious reports, and
produces a restricted sample that may be largely reliable. This subset is
highly correlated geographically with the catalog of outgassing events seen by
the Apollo 15, 16 and Lunar Prospector alpha-particle spectrometers for
episodic Rn-222 gas release. Both this robust TLP sample and even the larger,
unfiltered sample are highly correlated with the boundary between mare and
highlands, as are both deep and shallow moonquakes, as well as Po-210, a
long-lived product of Rn-222 decay and a further tracer of outgassing. This
offers another significant correlation relating TLPs and outgassing, and may
tie some of this activity to sagging mare basalt plains (perhaps mascons).
Additionally, low-level but likely significant TLP activity is connected to
recent, major impact craters (while moonquakes are not), which may indicate the
effects of cracks caused by the impacts, or perhaps avalanches, allowing
release of gas. The majority of TLP (and Rn-222) activity, however, is confined
to one site that produced much of the basalt in the Procellarum Terrane, and it
seems plausible that this TLP activity may be tied to residual outgassing from
the formerly largest volcanic ffusion sites from the deep lunar interior. With
the coming in the next few years of robotic spacecraft followed by human
exploration, the study of TLPs and outgassing is both promising and imperiled.
We will have an unprecedented pportunity to study lunar outgassing, but will
also deal with a greater burden of anthropogenic lunar gas than ever produced.
There is a pressing need to study lunar atmosphere and its sources while still
pristine. [Abstract abridged.]
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:34:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Crotts",
"Arlin P. S.",
""
]
] |
0706.3950 | Clifton Ealy | Alexander Berenstein, Clifton Ealy, Ayhan G\"unaydin | Thorn independence in the field of real numbers with a small
multiplicative group | null | null | null | null | math.LO | null | We characterize thorn-independence in a variety of structures, focusing on
the field of real numbers expanded by predicate defining a dense multiplicative
subgroup, G, satisfying the Mann property and whose pth powers are of finite
index in G. We also show such structures are super-rosy and eliminate
imaginaries up to codes for small sets.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:42:03 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Berenstein",
"Alexander",
""
],
[
"Ealy",
"Clifton",
""
],
[
"Günaydin",
"Ayhan",
""
]
] |
0706.3951 | Michael Luke Walker | M.L. Walker | Extending SU(2) to SU(N) QCD | 12 pages, errors corrected | Phys.Lett.B662:383-387,2008 | 10.1016/j.physletb.2008.03.015 | null | hep-th | null | Abelian dominance is used to reformulate the QCD Lagrangian as a sum over the
roots of Lie group representation theory. This greatly facilitates extending
the SU(2) magnetic ground state energy spectrum, several arguments for the
stability of the magnetic ground state, and the Faddeev-Skyrme model to
arbitrary SU(N) QCD.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:44:56 GMT"
},
{
"version": "v2",
"created": "Mon, 30 Jul 2007 23:22:28 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Walker",
"M. L.",
""
]
] |
0706.3952 | Arlin Crotts | Arlin P.S. Crotts and Cameron Hummels | Lunar Outgassing, Transient Phenomena and The Return to The Moon, II:
Predictions for Interactions between Outgassing and Regolith | 23 pages, 2 figures, submitted to ApJ. Other papers in series found
at http://www.astro.columbia.edu/~arlin/TLP/ | Astrophys.J.707:1506-1523,2009 | 10.1088/0004-637X/707/2/1506 | null | astro-ph | null | We consider the implications from Paper I on how gas leaking through the
lunar surface might interact with the regolith, and in what respects this might
affect or cause the appearance of optical Transient Lunar Phenomena (TLPs). We
consider briefly a range of phenomena, but concentrate at the extremes of high
and low gas flow rate, which might represent the more likely behaviors.
Extremely fast i.e., explosive, expulsion of gas from the surface is
investigated by examining the minimal amount of gas needed to displace a plug
of regolith above a site of gaseous overpressure at the regolith's base. The
area and timescale of this disturbance, it is consistent with observed TLPs.
Furthermore there are several ways in which such an explosion might be expected
to change the lunar surface appearance in a way consistent with many TLPs,
including production of obscuration, brightening and color changes. At the slow
end of the volatile flow range, gas seeping from the interior is retained below
the surface for extensive times due to the low diffusivity of regolith
material. A special circumstance arises if the volatile flow contains water
vapor, because water is uniquely capable of freezing as it passes from the base
to the surface of the regolith. For a large TLP site, it is plausible to think
of areas on the square-km scale accumulating significant bodies of water ice.
Furthermore, as the system evolves over geological time, the ice accumulation
zone will evolve downwards into the regolith. Since many reactions possible
between the volatiles and regolith, depending on the additional gases besides
water, can act to decrease diffusivity in the regolith, it is plausible that
the volatiles produce a barrier between the seepage source and vacuum, forcing
the ice zone to expand to larger areas.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 03:48:47 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Crotts",
"Arlin P. S.",
""
],
[
"Hummels",
"Cameron",
""
]
] |
0706.3953 | Tawanda Gwena | Tawanda Gwena, Montserrat Teixidor i Bigas | Maps between moduli spaces of vector bundles and the base locus of the
theta divisor | 6 pages | null | null | null | math.AG | null | Given a vector bundle $E$ of rank $r$ and degree $d$ on a curve $C$ of genus
$g$, one can associate to $E$ in a natural way several other vector bundles.
For example, one can take wedge powers of $E$. If $E$ is generated by global
sections, the kernel of the evaluation map of sections is again a vector
bundle. Also, new vector bundles can be produced by taking elementary
transformations centered at a fixed point. Under suitable conditions on degree
and rank, these constructions can be carried out globally. While all this
processes seem quite elementary, very little is known about the resulting maps.
The purpose of this paper is to fill in this gap.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:08:43 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Gwena",
"Tawanda",
""
],
[
"Bigas",
"Montserrat Teixidor i",
""
]
] |
0706.3954 | Arlin Crotts | Arlin P.S. Crotts | Lunar Outgassing, Transient Phenomena and The Return to The Moon, III:
Observational and Experimental Techniques | 33 pages, 4 figures, submitted to ApJ. Figures 5-6 and other papers
in series found at http://www.astro.columbia.edu/~arlin/TLP/ | null | null | null | astro-ph | null | In Papers II and III we show that Transient Lunar Phenomena (TLPs) are likely
related to lunar outgassing, albeit in ways not fully understood. Here we
propose a path forward, in which current and forthcoming technologies provide a
more controlled, sensitive probe of lunar outgassing. Many of these techniques
are being realized for the first time. Given the optical transient/outgassing
connection, progress can be made by remote sensing, and we suggest programs of
imaging, spectroscopy and combinations thereof. However, as found in Paper II,
many aspects of lunar outgassing seem covert in nature. TLPs betray outgassing,
but not all outgassing produces TLPs. Some outgassing may never appear at the
surface, but remain trapped in the regolith. We also suggest more intrusive
techniques, from radar mapping to in-situ probes. Understanding these volatiles
seems promising in terms of a resource for humans on the Moon and beyond, and
offers an interesting scientific goal in its own right. Hence this paper is a
series of proposed techniques, some in practice, some which might be soon, and
some requiring significant future investment, some of which may prove unwise
pending results from predecessor investigations. These point towards
enhancement of our knowledge of lunar outgassing, its relation to other lunar
processes, and an increase in our understanding of how volatiles are involved
in the evolution of the Moon. We emphasize certain ground-based observations in
time for flights of SELENE, LRO and other robotic missions, and others before
extensive human xploration. We discuss how study of the pristine lunar
atmosphere pertains to understanding the role of anthropogenic volatiles, an
important confusing signal
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:20:31 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Crotts",
"Arlin P. S.",
""
]
] |
0706.3955 | Sadaharu Uehara | The Belle Collaboration: S.Uehara, et al | Study of charmonia in four-meson final states produced in two-photon
collisions | 22 pages, 12 figures | Eur.Phys.J.C53:1-14,2008 | 10.1140/epjc/s10052-007-0451-z | Belle Preprint 2007-29, KEK Preprint 2007-26 | hep-ex | null | We report measurements of charmonia produced in two-photon collisions and
decaying to four-meson final states, where the meson is either a charged pion
or a charged kaon. The analysis is based on a 395fb^{-1} data sample
accumulated with the Belle detector at the KEKB electron-positron collider. We
observe signals for the three C-even charmonia eta_c(1S), chi_{c0}(1P) and
chi_{c2}(1P) in the pi^+pi^-pi^+pi^-, K^+K^-pi^+pi^- and K^+K^-K^+K^- decay
modes. No clear signals for eta_c(2S) production are found in these decay
modes. We have also studied resonant structures in charmonium decays to
two-body intermediate meson resonances. We report the products of the
two-photon decay width and the branching fractions, Gamma_{gamma gamma}B, for
each of the charmonium decay modes.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:45:52 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Dec 2007 05:00:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"The Belle Collaboration",
"",
""
],
[
"Uehara",
"S.",
""
]
] |
0706.3956 | Michio Otsuki | Hisao Hayakawa and Michio Otsuki | Long-time tails in freely cooling granular gases | 26 pages, 5 figures | Phys. Rev. E, 76, 051304 (2007) | 10.1103/PhysRevE.76.051304 | null | cond-mat.stat-mech cond-mat.soft | null | The long-time behavior of the current auto-correlation functions for the
velocity, the shear stress and the heat flux is investigated in freely cooling
granular gases. It is found that the correlation functions for the velocity and
the shear stress have the long-time tails obeying $\tau^{-d/2}$, while the
correlation function of heat flux decays as $\tau^{-(d+2)/2} \exp(-\zeta^*
\tau)$ with the dimensionless cooling rate $\zeta^*$, the spatial dimension $d$
and the scaled time $\tau$ in terms of the collision frequency. The result of
our numerical simulation of the freely cooling granular gases is consistent
with the theoretical prediction.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 05:20:55 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 01:17:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hayakawa",
"Hisao",
""
],
[
"Otsuki",
"Michio",
""
]
] |
0706.3957 | Chenyang Xu | Chenyang Xu | Notes on $\pi_1$ of Smooth Loci of Log Del Pezzo Surfaces | 28 pages. Mistakes corrected and exposition improved | null | null | null | math.AG | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | It is known that the fundamental groups of smooth loci of Log del Pezzo
Surfaces are finite groups. The aim of this note is to study these finite
groups. A short table containing these groups is given. And lots of groups on
the table are proved to be fundamental groups.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:49:18 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Nov 2008 20:37:05 GMT"
}
] | 2008-11-03T00:00:00 | [
[
"Xu",
"Chenyang",
""
]
] |
0706.3958 | A. K. Chaudhuri | A. K. Chaudhuri | Di-jet hadron pair correlation in a hydrodynamical model with a
quenching jet | 5 pages, 4 figures. Some minor corrections are made in the revised
manuscript | Phys.Rev.C77:027901,2008 | 10.1103/PhysRevC.77.027901 | null | nucl-th | null | In jet quenching, a hard QCD parton, before fragmenting into a jet of
hadrons, deposits a fraction of its energy in the medium, leading to suppressed
production of high-$p_T$ hadrons. Assuming that the deposited energy quickly
thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP
fluid. Hydrodynamic evolution and subsequent particle emission depend on the
jet trajectories. Azimuthal distribution of excess $\pi^-$ due to quenching
jet, averaged over all the trajectories, reasonably well reproduce the
di-hadron correlation as measured by the STAR and PHENIX collaboration in
central and in peripheral Au+Au collisions.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 04:57:12 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jan 2008 05:03:55 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chaudhuri",
"A. K.",
""
]
] |
0706.3959 | Fu-Yan Bian | Wei-Gang Wang (1) and Yu-Qing Lou (1, 2 and 3) ((1)Tsinghua Center for
Astrophysics, (2)Department of Astronomy and Astrophysics, The University of
Chicago, (3)National Astronomical Observatories, Chinese Academy of Sciences) | Self-Similar Dynamics of a Magnetized Polytropic Gas | 37 pages, 36 figures, accepted by Astrophysics and Space Science | Astrophys.Space Sci.311:363-400,2007 | 10.1007/s10509-007-9545-1 | null | astro-ph | null | In broad astrophysical contexts of large-scale gravitational collapses and
outflows and as a basis for various further astrophysical applications, we
formulate and investigate a theoretical problem of self-similar MHD for a
non-rotating polytropic gas of quasi-spherical symmetry permeated by a
completely random magnetic field. We derive two coupled nonlinear MHD ordinary
differential equations (ODEs), examine properties of the magnetosonic critical
curve, obtain various asymptotic and global semi-complete similarity MHD
solutions, and qualify the applicability of our results. Unique to a magnetized
gas cloud, a novel asymptotic MHD solution for a collapsing core is
established. Physically, the similarity MHD inflow towards the central dense
core proceeds in characteristic manners before the gas material eventually
encounters a strong radiating MHD shock upon impact onto the central compact
object. Sufficiently far away from the central core region enshrouded by such
an MHD shock, we derive regular asymptotic behaviours. We study asymptotic
solution behaviours in the vicinity of the magnetosonic critical curve.
Numerically, we construct global semi-complete similarity MHD solutions that
cross the magnetosonic critical curve zero, one, and two times. For comparison,
counterpart solutions in the case of an isothermal unmagnetized and magnetized
gas flows are demonstrated in the present MHD framework at nearly isothermal
and weakly magnetized conditions. For a polytropic index $\gamma=1.25$ or a
strong magnetic field, different solution behaviours emerge. In these cases,
there exist semi-complete similarity solutions crossing the magnetosonic
critical curve only once, and the MHD counterpart of expansion-wave collapse
solution disappears.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 05:10:39 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Wang",
"Wei-Gang",
"",
"1, 2 and 3"
],
[
"Lou",
"Yu-Qing",
"",
"1, 2 and 3"
]
] |
0706.3960 | Ben Lillie | Ben Lillie, Jing Shu, and Tim M.P. Tait | Kaluza-Klein Gluons as a Diagnostic of Warped Models | 25 pages, 10 figures | Phys.Rev.D76:115016,2007 | 10.1103/PhysRevD.76.115016 | ANL-HEP-PR-07-40, EFI/07-18 | hep-ph | null | We study the properties of $g^{1}$, the first excited state of the gluon in
representative variants of the Randall Sundrum model with the Standard Model
fields in the bulk. We find that measurements of the coupling to light quarks
(from the inclusive cross-section for $pp\to g^{1} \to t\bar t$), the coupling
to bottom quarks (from the rate of $pp\to g^{1} b$), as well as the overall
width, can provide powerful discriminants between the models. In models with
large brane kinetic terms, the $g^1$ resonance can even potentially be
discovered decaying into dijets against the large QCD background. We also
derive bounds based on existing Tevatron searches for resonant $t \bar{t}$
production and find that they require $M_{g^{1}} \gtrsim 950$ GeV. In addition
we explore the pattern of interference between the $g^1$ signal and the
non-resonant SM background, defining an asymmetry parameter for the invariant
mass distribution. The interference probes the relative signs of the couplings
of the $g^{1}$ to light quark pairs and to $t\bar t$, and thus provides an
indication that the top is localized on the other side of the extra dimension
from the light quarks, as is typical in the RS framework.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 05:21:44 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lillie",
"Ben",
""
],
[
"Shu",
"Jing",
""
],
[
"Tait",
"Tim M. P.",
""
]
] |
0706.3961 | Li Zhigang | Li zhigang, Wei-Tou Ni, Antonio Pulido Paton | Extra dimensions and atomic transition frequencies | 8 pages, 1 figure | Chin.Phys.B17:70-76,2008 | 10.1088/1674-1056/17/1/013 | null | gr-qc | null | New unification theories predict Large Extra Dimensions (LEDs). If that is
the case, gravity would be stronger at short ranges than what Newtonian gravity
predicts. LEDs could also have effects at atomic level. In this paper we
propose a new method to constrain the size of gravity-only LEDs by analyzing
how these LEDs modify the energy of the atomic transitions 1s-2s and 2s-2p
(Lamb shift), for the particular case of the hydrogen and muonium atoms. We
estimate these effects by using Bethe's non-relativistic treatment of Lamb
shift. For the particular case of three LEDs, which may be a candidate to
explain the interaction mechanism of dark matter particles, we have found that
current knowledge in atomic spectroscopy could constrain their sizes to be less
than 10 * 10^(-6) m. Although our contributions do not reach the sensitivity
given by SN1987a, they are still slightly better than recent constraints given
by Inverse Square Law tests of Eot-Wash group at Washington University, which
gave R3 < 36.6 * 10^(-6) m.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 06:44:52 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"zhigang",
"Li",
""
],
[
"Ni",
"Wei-Tou",
""
],
[
"Paton",
"Antonio Pulido",
""
]
] |
0706.3962 | Ian Percival | Ian Percival and Barry Garraway | Quantum measurement, detection and locality | 11 pages, 2 figures To be published in Phys. Lett. A | null | 10.1016/j.physleta.2007.05.072 | null | quant-ph | null | According to Bell's theorem, local realism is incompatible with quantum
theory. However, it depends on an implied assumption about quantum measurement.
We suggest that the assumption might be removed by a detailed quantum analysis
of the interaction between the measured system and measuring apparatus using
Born's statistical interpretation. But it is conceivable that detailed analysis
of all possible Bell experiments would allow the compatibility of quantum
theory and local realism. The difficulties of theory and experiment are closely
related.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:28:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Percival",
"Ian",
""
],
[
"Garraway",
"Barry",
""
]
] |
0706.3963 | Angela Baier | Th. Posch (1), A. Baier (1), H. Mutschke (2), Th. Henning (3) ((1)
Institute for Astronomy, University of Vienna, (2) AIU Jena, Germany (3) Max
Planck Institute for Astronomy (MPIA), Heidelberg, Germany) | Carbonates in space - The challenge of low temperature data | 20 pages, 10 figures, accepted by ApJ, corrected typos | null | 10.1086/521390 | null | astro-ph | null | Carbonates have repeatedly been discussed as possible carriers of stardust
emission bands. However, the band assignments proposed so far were mainly based
on room temperature powder transmission spectra of the respective minerals.
Since very cold calcite grains have been claimed to be present in protostars
and in Planetary Nebulae such as NGC 6302, the changes of their dielectric
functions at low temperatures are relevant from an astronomical point of view.
We have derived the IR optical constants of calcite and dolomite from
reflectance spectra - measured at 300, 200, 100 and 10K - and calculated small
particle spectra for different grain shapes, with the following results: i) The
absorption efficiency factors both of calcite and dolomite are extremely
dependent on the particle shapes. This is due to the high peak values of the
optical constants of CaCO3 and CaMg[CO3]2. ii) The far infrared properties of
calcite and dolomite depend also very significantly on the temperature. Below
200K, a pronounced sharpening and increase in the band strengths of the FIR
resonances occurs. iii) In view of the intrinsic strength and sharpening of the
44 mum band of calcite at 200-100K, the absence of this band -- inferred from
Infrared Space Observatory data -- in PNe requires dust temperatures below 45K.
iv) Calcite grains at such low temperatures can account for the '92' mum band,
while our data rule out dolomite as the carrier of the 60-65 mum band. The
optical constants here presented are publicly available in the electronic
database http://www.astro.uni-jena.de/Laboratory/OCDB
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:42:51 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Jul 2007 12:42:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Posch",
"Th.",
""
],
[
"Baier",
"A.",
""
],
[
"Mutschke",
"H.",
""
],
[
"Henning",
"Th.",
""
]
] |
0706.3964 | Pavel Tumarkin | Anna Felikson, Pavel Tumarkin | Coxeter polytopes with a unique pair of non-intersecting facets | 28 pages, lots of figures; v2: Lemma 2.2.1 corrected (thanks to Ruth
Kellerhals for the correction!), further minor changes | J. Combin. Theory A 116 (2009), 875--902 | 10.1016/j.jcta.2008.10.008 | null | math.MG math.CO math.GR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider compact hyperbolic Coxeter polytopes whose Coxeter diagram
contains a unique dotted edge. We prove that such a polytope in d-dimensional
hyperbolic space has at most d+3 facets. In view of results of Lann\'er,
Kaplinskaja, Esselmann, and the second author, this implies that compact
hyperbolic Coxeter polytopes with a unique pair of non-intersecting facets are
completely classified. They do exist only up to dimension 6 and in dimension 8.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:33:26 GMT"
},
{
"version": "v2",
"created": "Sun, 11 Sep 2022 00:04:11 GMT"
}
] | 2022-09-13T00:00:00 | [
[
"Felikson",
"Anna",
""
],
[
"Tumarkin",
"Pavel",
""
]
] |
0706.3965 | Bradley A. Foreman | Lu Ding, Chunlei Yang, Hongtao He, Fengyi Jiang, Jiannong Wang, Zikang
Tang, Bradley A. Foreman, Weikun Ge | Unambiguous symmetry assignment for the top valence band of ZnO by
magneto-optical studies of the free A-exciton state | 5 pages, 4 figures | null | null | null | cond-mat.mtrl-sci | null | We studied the circular polarization and angular dependences of the
magneto-photoluminescence spectra of the free A-exciton 1S state in wurtzite
ZnO at T = 5 K. The circular polarization properties of the spectra clearly
indicate that the top valence band has Gamma_7 symmetry. The out-of-plane
component of the magnetic field, which is parallel to the sample's c axis,
leads to linear Zeeman splitting of both the dipole-allowed Gamma_5 exciton
state and the weakly allowed Gamma_1/Gamma_2 exciton states. The in-plane
field, which is perpendicular to the c axis, increases the oscillator strength
of the weak Gamma_1/Gamma_2 states by forming a mixed exciton state.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:00:45 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Ding",
"Lu",
""
],
[
"Yang",
"Chunlei",
""
],
[
"He",
"Hongtao",
""
],
[
"Jiang",
"Fengyi",
""
],
[
"Wang",
"Jiannong",
""
],
[
"Tang",
"Zikang",
""
],
[
"Foreman",
"Bradley A.",
""
],
[
"Ge",
"Weikun",
""
]
] |
0706.3966 | Howard M. Wiseman | R. Mir, J. S. Lundeen, M. W. Mitchell, A. M. Steinberg, J. L.
Garretson, H. M. Wiseman | A double-slit `which-way' experiment on the complementarity--uncertainty
debate | 13 pages, 4 figures | New J. Phys. 9 (2007) 287. | 10.1088/1367-2630/9/8/287 | null | quant-ph | null | A which-way measurement in Young's double-slit will destroy the interference
pattern. Bohr claimed this complementarity between wave- and particle behaviour
is enforced by Heisenberg's uncertainty principle: distinguishing two positions
a distance s apart transfers a random momentum q \sim \hbar/s to the particle.
This claim has been subject to debate: Scully et al. asserted that in some
situations interference can be destroyed with no momentum transfer, while
Storey et al. asserted that Bohr's stance is always valid. We address this
issue using the experimental technique of weak measurement. We measure a
distribution for q that spreads well beyond [-\hbar/s, \hbar/s], but
nevertheless has a variance consistent with zero. This weakvalued
momentum-transfer distribution P_{wv}(q) thus reflects both sides of the
debate.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:02:25 GMT"
},
{
"version": "v2",
"created": "Wed, 29 Aug 2007 18:22:57 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mir",
"R.",
""
],
[
"Lundeen",
"J. S.",
""
],
[
"Mitchell",
"M. W.",
""
],
[
"Steinberg",
"A. M.",
""
],
[
"Garretson",
"J. L.",
""
],
[
"Wiseman",
"H. M.",
""
]
] |
0706.3967 | Viktor Czinner | Viktor G. Czinner and Matyas Vasuth | Revisiting Rotational Perturbations and the Microwave Background | accepted for publication in Int. J. Mod. Phys. D | Int.J.Mod.Phys.D16:1715-1723,2007 | 10.1142/S0218271807011176 | null | astro-ph | null | We consider general-relativistic rotational perturbations in homogeneous and
isotropic Friedman - Robertson - Walker (FRW) cosmologies. Taking linear
perturbations of FRW models, the general solution of the field equations
contains tensorial, vectorial and scalar functions. The vectorial terms are in
connection with rotations in the given model and due to the Sachs - Wolfe
effect they produce contributions to the temperature fluctuations of the cosmic
microwave background radiation (CMBR). In present paper we obtain the analytic
time dependence of these contributions in a spatially flat, FRW model with
pressureless ideal fluid, in the presence and the absence of a cosmological
constant. We find that the solution can be separated into an integrable and a
non-integrable part as is the situation in the case of scalar perturbations.
Analyzing the solutions and using the results of present observations we
estimate the order of magnitude of the angular velocity corresponding to the
rotation tensor at the time of decoupling and today.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:03:48 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 07:30:41 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Czinner",
"Viktor G.",
""
],
[
"Vasuth",
"Matyas",
""
]
] |
0706.3968 | Lutz Duembgen | Lutz Duembgen, G\"unther Walther | Multiscale inference about a density | Version 2 is an extended version (Technical report 56, IMSV, Univ.
Bern) which is referred to in version 3. Published in at
http://dx.doi.org/10.1214/07-AOS521 the Annals of Statistics
(http://www.imstat.org/aos/) by the Institute of Mathematical Statistics
(http://www.imstat.org) | Annals of Statistics 2008, Vol. 36, No. 4, 1758-1785 | 10.1214/07-AOS521 | IMS-AOS-AOS521 | math.ST stat.TH | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a multiscale test statistic based on local order statistics and
spacings that provides simultaneous confidence statements for the existence and
location of local increases and decreases of a density or a failure rate. The
procedure provides guaranteed finite-sample significance levels, is easy to
implement and possesses certain asymptotic optimality and adaptivity
properties.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:15:43 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 09:44:22 GMT"
},
{
"version": "v3",
"created": "Thu, 7 Aug 2008 11:28:12 GMT"
}
] | 2008-08-07T00:00:00 | [
[
"Duembgen",
"Lutz",
""
],
[
"Walther",
"Günther",
""
]
] |
0706.3969 | Debabrata Panja | Debabrata Panja and Gerard T. Barkema | Passage Times for Polymer Translocation Pulled through a Narrow Pore | 7 pages, 4 figures, 6 eps figure files, minor expressions changed,
references updated; to appear in Biophys. J | Biophys. J. 94, 1630-1637 (2008) | 10.1529/biophysj.107.116434 | null | cond-mat.soft cond-mat.stat-mech physics.bio-ph q-bio.BM | null | We study the passage times of a translocating polymer of length $N$ in three
dimensions, while it is pulled through a narrow pore with a constant force $F$
applied to one end of the polymer. At small to moderate forces, satisfying the
condition $FN^{\nu}/k_BT\lesssim1$, where $\nu\approx0.588$ is the Flory
exponent for the polymer, we find that $\tau_N$, the mean time the polymer
takes to leave the pore, scales as $N^{2+\nu}$ independent of $F$, in agreement
with our earlier result for F=0. At strong forces, i.e., for
$FN^{\nu}/k_BT\gg1$, the behaviour of the passage time crosses over to
$\tau_N\sim N^2/F$. We show here that these behaviours stem from the polymer
dynamics at the immediate vicinity of the pore -- in particular, the memory
effects in the polymer chain tension imbalance across the pore.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:41:21 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 13:10:46 GMT"
},
{
"version": "v3",
"created": "Thu, 16 Aug 2007 12:56:22 GMT"
}
] | 2008-02-14T00:00:00 | [
[
"Panja",
"Debabrata",
""
],
[
"Barkema",
"Gerard T.",
""
]
] |
0706.3970 | Georg Hein | Georg Hein | Raynaud vector bundles | 11 pages | null | null | null | math.AG | null | We construct vector bundles $R^r_\mu$ on a smooth projective curve $X$ having
the property that for all sheaves $E$ of slope $\mu$ and rank $r$ on $X$ we
have an equivalence: $E$ is a semistable vector bundle $\iff$
$Hom(R^r_\mu,E)=0$.
As a byproduct of our construction we obtain effective bounds on $r$ such
that the linear system $|R \cdot \Theta|$ has base points on the moduli space
$U_X(r,r(g-1))$.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:40:46 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Hein",
"Georg",
""
]
] |
0706.3971 | Romain Tessera | Romain Tessera | On the L^p-distorsion of finite quotients of amenable groups | 8 pages | null | null | null | math.MG | null | We study the L^p-distortion of finite quotients of amenable groups. In
particular, for every number p larger or equal than 2, we prove that the
l^p-distortion of the finite lamplighter group grows like (\log n)^{1/p}. We
also give the asymptotic behavior of the l^p-distortion of finite quotients of
certain metabelian polycyclic groups and of the solvable Baumslag-Solitar
groups BS(m,1). The proofs are short and elementary.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 17:59:14 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 15:35:57 GMT"
},
{
"version": "v3",
"created": "Tue, 30 Oct 2007 23:00:57 GMT"
}
] | 2007-10-31T00:00:00 | [
[
"Tessera",
"Romain",
""
]
] |
0706.3972 | Nicola La Palombara | N. La Palombara, S. Mereghetti (INAF/IASF-Milano) | XMM-Newton observation of the persistent Be/neutron-star system X Persei
at a high-luminosity level | 8 pages, 8 figures, 4 tables. Accepted for publication by Astronomy &
Astrophysics | null | 10.1051/0004-6361:20077970 | null | astro-ph | null | We report on the XMM-Newton observation of the HMXRB X Persei, the prototype
of the persistent and low-luminosity Be/neutron star pulsars, which was
performed on February 2003. The source was detected at a luminosity level of ~
1.4x10^35 erg/s, which is the highest level of the latest three decades. The
pulsation period has increased up to 839.3 s, thus confirming the overall
spin-down of the NS detected in the previous observations. The folded
light-curve has a complex structure, with features not observed at lower
luminosities, and shows a significant energy dependence. The spectral analysis
reveals the presence of a significant excess at low energies over the main
power-law spectral component, which can be described by a black-body spectrum
of high temperature (kT_BB ~ 1.5 keV) and small emitting region (R_BB ~ 340 m);
its properties are consistent with a polar-cap origin. Phase-resolved
spectroscopy shows that the emission spectrum varies along the pulse period,
but it is not possible to prove whether the thermal component is pulsed or not.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:45:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"La Palombara",
"N.",
"",
"INAF/IASF-Milano"
],
[
"Mereghetti",
"S.",
"",
"INAF/IASF-Milano"
]
] |
0706.3973 | Wolfgang Steimle | Wolfgang Steimle | Whitehead-Torsion und Faserungen | Diploma thesis written at the WWU Muenster, Germany, supervised by
Wolfgang Lueck. In German, 79 pages | null | null | null | math.GT | null | This work treats on the question whether a given map f: M -> B of smooth
closed manifolds is homotopic to a smooth fiber bundle. We define a first
obstruction in H^1(B;Wh(\pi_1(E))) and, provided that this obstruction vanishes
and one additional condition is verified, a second obstruction in Wh(\pi_1(E))
>. Both elements vanish if the answer to the above question is positive. In the
case where B is the 1-sphere and the dimension of M exceeds five, we show that
the converse is also true, using a relationship with two obstructions defined
by Farrell in this particular situation.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:52:03 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Steimle",
"Wolfgang",
""
]
] |
0706.3974 | Pierre-Henri Chavanis | Pierre-Henri Chavanis and Clement Sire | Kinetic and hydrodynamic models of chemotactic aggregation | In press | Physica A, 384, 199 (2007) | 10.1016/j.physa.2007.05.069 | null | physics.bio-ph | null | We derive general kinetic and hydrodynamic models of chemotactic aggregation
that describe certain features of the morphogenesis of biological colonies
(like bacteria, amoebae, endothelial cells or social insects). Starting from a
stochastic model defined in terms of N coupled Langevin equations, we derive a
nonlinear mean field Fokker-Planck equation governing the evolution of the
distribution function of the system in phase space. By taking the successive
moments of this kinetic equation and using a local thermodynamic equilibrium
condition, we derive a set of hydrodynamic equations involving a damping term.
In the limit of small frictions, we obtain a hyperbolic model describing the
formation of network patterns (filaments) and in the limit of strong frictions
we obtain a parabolic model which is a generalization of the standard
Keller-Segel model describing the formation of clusters (clumps). Our approach
connects and generalizes several models introduced in the chemotactic
literature. We discuss the analogy between bacterial colonies and
self-gravitating systems and between the chemotactic collapse and the
gravitational collapse (Jeans instability). We also show that the basic
equations of chemotaxis are similar to nonlinear mean field Fokker-Planck
equations so that a notion of effective generalized thermodynamics can be
developed.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 07:53:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chavanis",
"Pierre-Henri",
""
],
[
"Sire",
"Clement",
""
]
] |
0706.3975 | Luciano da Fontoura Costa | Bruno A. N. Travencolo and Luciano da F. Costa | Hierarchical Spatial Organization of Geographical Networks | 3 page, 3 figures. A wokring manuscript: suggestions welcomed | null | 10.1088/1751-8113/41/22/224004 | null | physics.soc-ph | null | In this work we propose the use of a hirarchical extension of the
polygonality index as a means to characterize and model geographical networks:
each node is associated with the spatial position of the nodes, while the edges
of the network are defined by progressive connectivity adjacencies. Through the
analysis of such networks, while relating its topological and geometrical
properties, it is possible to obtain important indications about the
development dynamics of the networks under analysis. The potential of the
methodology is illustrated with respect to synthetic geographical networks.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:07:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Travencolo",
"Bruno A. N.",
""
],
[
"Costa",
"Luciano da F.",
""
]
] |
0706.3976 | Jasper van Wezel | Jasper van Wezel, Tjerk Oosterkamp and Jan Zaanen | Towards an Experimental Test of Gravity-induced Quantum State Reduction | 12 pages, 7 figures | Phil. Mag., 88, 1005 (2008) | 10.1080/14786430801941824 | null | cond-mat.str-el cond-mat.other quant-ph | null | According to the hypothesis of Penrose and Diosi, quantum state reduction is
a manifestation of the incompatibilty of general relativity and the unitary
time evolution of quantum physics. Dimensional analysis suggests that
Schrodinger cat type states should collapse on measurable time scales when
masses and lengths of the order of bacterial scales are involved. We analyze
this hypothesis in the context of modern developments in condensed matter and
cold atoms physics, aimed at realizing macroscopic quantum states. We first
consider 'micromechanical' quantum states, analyzing the capacity of an atomic
force microscopy based single spin detector to measure the gravitational state
reduction, but we conclude that it seems impossible to suppress environmental
decoherence to the required degree. We subsequently discuss 'split' cold atom
condensates to find out that these are at present lacking the required mass
scale by many orders of magnitude. We then extent Penrose's analysis to
superpositions of mass current carrying states, and we apply this to the flux
quantum bits realized in superconducting circuits. We find that the flux qubits
approach the scale where gravitational state reduction should become
measurable, but bridging the few remaining orders of magnitude appears to be
very difficult with present day technology.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:18:23 GMT"
}
] | 2010-04-29T00:00:00 | [
[
"van Wezel",
"Jasper",
""
],
[
"Oosterkamp",
"Tjerk",
""
],
[
"Zaanen",
"Jan",
""
]
] |
0706.3977 | Martin Oettel | A. Dominguez, D. Frydel and M. Oettel | Multipolar expansion of the electrostatic interaction between charged
colloids at interfaces | 6 pages, mathematical details added | Phys. Rev. E 77, 020401(R) (2008) | 10.1103/PhysRevE.77.020401 | null | cond-mat.soft | null | The general form of the electrostatic potential around an arbitrarily charged
colloid at an interface between a dielectric and a screening phase (such as air
and water, respectively) is analyzed in terms of a multipole expansion. The
leading term is isotropic in the interfacial plane and varies with $d^{-3}$
where $d$ is the in--plane distance from the colloid. The electrostatic
interaction potential between two arbitrarily charged colloids is likewise
isotropic and $\propto d^{-3}$, corresponding to the dipole--dipole interaction
first found for point charges at water interfaces. Anisotropic interaction
terms arise only for higher powers $d^{-n}$ with $n \ge 4$.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:17:53 GMT"
},
{
"version": "v2",
"created": "Tue, 23 Oct 2007 08:44:09 GMT"
}
] | 2008-07-11T00:00:00 | [
[
"Dominguez",
"A.",
""
],
[
"Frydel",
"D.",
""
],
[
"Oettel",
"M.",
""
]
] |
0706.3978 | Ingo Kirsch | Johanna Erdmenger, Kazuo Ghoroku, Ingo Kirsch | Holographic heavy-light mesons from non-Abelian DBI | 21 pages, 7 figures | JHEP0709:111,2007 | 10.1088/1126-6708/2007/09/111 | FIT HE-07-01, MPP-2007-74 | hep-th | null | In the context of gauge/gravity duals with flavor, we examine heavy-light
mesons which involve a heavy and a light quark. For this purpose we embed two
D7 brane probes at different positions into the gravity background. We
establish the non-Abelian Dirac-Born-Infeld (DBI) action for these probes, in
which the U(2) matrix describing the embedding is diagonal. The fluctuations of
the brane probes correspond to the mesons. In particular, the off-diagonal
elements of the U(2) fluctuation matrix correspond to the heavy-light mesons,
while the diagonal elements correspond to the light-light and heavy-heavy
mesons, respectively. The heavy-light mesons scale differently with the 't
Hooft coupling than the mesons involving quarks of equal mass. The model
describes both scalar and vector mesons. For different dilaton-deformed gravity
backgrounds, we also calculate the Wilson loop energy, and compare with the
meson masses.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 16:41:25 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 08:13:35 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Erdmenger",
"Johanna",
""
],
[
"Ghoroku",
"Kazuo",
""
],
[
"Kirsch",
"Ingo",
""
]
] |
0706.3979 | Sergey Shevchenko | S.V. Shevchenko and V.V. Tokarevsky | The informational model - possible tests | null | null | null | null | physics.gen-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In our previous arXiv papers (more systematically the informational
conception is presented in the paper "The Information as Absolute", 2010) it
was rigorously shown that Matter in our Universe - and Universe as a whole -
are some informational systems (structures), which exist as uninterruptedly
transforming [practically] infinitesimal sub-sets in the absolutely infinite
and fundamental set "Information". Such a conception allows to suggest a
reasonable physical model that is based on the conjecture that Matter is some
analogue of computer (more correct - of a [huge] number of mutually
comparatively independent automata). The conjecture, in turn, allows
introducing in the model the basic logical elements that constitute the
material structures and support the informational exchange - i.e. the forces -
between the structures. The model yet now makes more clear a number of basic
problems in special relativity, quantum mechanics, and, rather probably, in
[now - in Newtonian] gravity. In this paper some possible experiments for the
model testing are considered.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:32:13 GMT"
},
{
"version": "v2",
"created": "Sat, 6 Nov 2010 22:52:55 GMT"
},
{
"version": "v3",
"created": "Wed, 4 May 2011 08:52:43 GMT"
}
] | 2011-05-05T00:00:00 | [
[
"Shevchenko",
"S. V.",
""
],
[
"Tokarevsky",
"V. V.",
""
]
] |
0706.3980 | Boris Kerbikov | B.O.Kerbikov | Fluctuation Propagator and Heavy Quark Diffusion | Contribution to the proceedings of the Rencontres de Moriond on QCD
and Hadronic Interactions, La Thuile, Italy, March 2007 | null | null | null | hep-ph | null | The quark fluctuation propagator is evaluated. It defines the diffusion
coefficient in the vicinity of the phase transition and the gradient term in
the Ginzburg-Landau functional.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:33:27 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Kerbikov",
"B. O.",
""
]
] |
0706.3981 | Giovanni Forni | Giovanni Forni | On the Greenfield-Wallach and Katok conjectures | 19 pages | null | null | null | math.DS | null | We survey recent progress on the Greenfield-Wallach and Katok conjectures on
globally hypoelliptic and cohomology free vector fields and derive a proof of
the conjectures in dimension three. The argument is primarily based on recent
work of F. and J. Rodriguez Hertz which allows us to reduce the question to the
case of a Reeb flow for a contact form. The contact case is settled by invoking
the Weinstein conjecture (which has been recently announced by C. Taubes).
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:55:51 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Forni",
"Giovanni",
""
]
] |
0706.3982 | Shun'ya Mizoguchi | H. Kunitomo and S. Mizoguchi | Lorentz anomaly in the semi-light-cone gauge superstrings | 20 pages, version published in Progress of Theoretical Physics | Prog.Theor.Phys.118:559-576,2007 | 10.1143/PTP.118.559 | YITP-07-38, KEK-TH-1161 | hep-th | null | We study the Lorentz invariance of D=4 and 6 superstrings in the
double-spinor formalism, which are equivalent to the D=4 and 6 superstrings in
the pure-spinor formalism in the sense of the BRST cohomology. We first
re-examine how the conformal and Lorentz anomalies appear in the D=4 and 6
Green-Schwarz superstrings in the semi-light-cone gauge in the framework of
BRST quantization. We construct a set of BRST invariant Lorentz generators and
show that they do not form a closed algebra, even cohomologically. We then turn
to the construction of Lorentz generators in the D=4 and 6 double-spinor
superstrings, and show that the Lorentz invariance is again anomalous. We also
discuss the relation between the anomaly-free Lorentz generators in the
lower-dimensional pure-spinor formalisms and that obtained in this paper.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:36:47 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Sep 2007 08:32:01 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Sep 2007 03:07:33 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kunitomo",
"H.",
""
],
[
"Mizoguchi",
"S.",
""
]
] |
0706.3983 | Dietrich Stauffer | D. Stauffer | Social applications of two-dimensional Ising models | 10 pages including all figures, teaching preprint for Am. J. Phys | null | 10.1119/1.2779882 | null | physics.soc-ph | null | I review three socio-economic models of economic opinions, urban segregation,
and language change and show that the well known two-dimensional Ising model
gives about the same results in each case.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 08:44:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stauffer",
"D.",
""
]
] |
0706.3984 | Ali Mesbah | Engin Bozdag, Ali Mesbah, Arie van Deursen | A Comparison of Push and Pull Techniques for Ajax | Conference: WSE 2007 | null | null | null | cs.SE cs.PF | null | Ajax applications are designed to have high user interactivity and low
user-perceived latency. Real-time dynamic web data such as news headlines,
stock tickers, and auction updates need to be propagated to the users as soon
as possible. However, Ajax still suffers from the limitations of the Web's
request/response architecture which prevents servers from pushing real-time
dynamic web data. Such applications usually use a pull style to obtain the
latest updates, where the client actively requests the changes based on a
predefined interval. It is possible to overcome this limitation by adopting a
push style of interaction where the server broadcasts data when a change occurs
on the server side. Both these options have their own trade-offs. This paper
explores the fundamental limits of browser-based applications and analyzes push
solutions for Ajax technology. It also shows the results of an empirical study
comparing push and pull.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:14:40 GMT"
},
{
"version": "v2",
"created": "Thu, 16 Aug 2007 11:53:37 GMT"
}
] | 2007-08-16T00:00:00 | [
[
"Bozdag",
"Engin",
""
],
[
"Mesbah",
"Ali",
""
],
[
"van Deursen",
"Arie",
""
]
] |
0706.3985 | John Aston | John A. D. Aston, Donald E. K. Martin | Distributions associated with general runs and patterns in hidden Markov
models | Published in at http://dx.doi.org/10.1214/07-AOAS125 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org) | Annals of Applied Statistics 2007, Vol. 1, No. 2, 585-611 | 10.1214/07-AOAS125 | IMS-AOAS-AOAS125 | stat.ME stat.AP stat.CO | null | This paper gives a method for computing distributions associated with
patterns in the state sequence of a hidden Markov model, conditional on
observing all or part of the observation sequence. Probabilities are computed
for very general classes of patterns (competing patterns and generalized later
patterns), and thus, the theory includes as special cases results for a large
class of problems that have wide application. The unobserved state sequence is
assumed to be Markovian with a general order of dependence. An auxiliary Markov
chain is associated with the state sequence and is used to simplify the
computations. Two examples are given to illustrate the use of the methodology.
Whereas the first application is more to illustrate the basic steps in applying
the theory, the second is a more detailed application to DNA sequences, and
shows that the methods can be adapted to include restrictions related to
biological knowledge.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:15:55 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 14:49:46 GMT"
}
] | 2007-12-18T00:00:00 | [
[
"Aston",
"John A. D.",
""
],
[
"Martin",
"Donald E. K.",
""
]
] |
0706.3986 | Mireille Calvet | Khosrow Chadan | Positivity of Some Integral Transforms, and Generalization of Bochner's
Theorem on Functions of Positive Type | null | null | null | null | math-ph math.MP | null | Using the integral representations of the solutions of Schr\"odinger
equation, which are the essential ingredients of the Gel'fand-Levitan and
Marchenko integral equations of inverse scattering theory, we obtain a general
theorem on the positivity of some integral transforms, and extend the theorem
of Bochner on Fourier transforms of functions of positive type to more general
transforms. The present study is restricted to the positive half-axis. We then
obtain a theorem on the positivity of Fourier cosine transform of the
phase-shifts.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:20:22 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Chadan",
"Khosrow",
""
]
] |
0706.3987 | Cristina Manuel | Massimo Mannarelli and Cristina Manuel | Exciting the quark-gluon plasma with a relativistic jet | 2 pages, 2 figures. Presented at "Heavy Ion Collisions at the LHC:
Last Call for Predictions", CERN, Geneva, May-June 2007 | null | null | null | hep-ph | null | We discuss the properties of a system composed by a static plasma traversed
by a jet of particles. Assuming that both the jet and the plasma can be
described using a hydrodynamical approach, and in the conformal limit, we find
that unstable modes arise when the velocity of the jet is larger than the speed
of the sound of the plasma and only modes with momenta smaller than a certain
values are unstable. Moreover, for ultrarelativistic velocities of the jet the
most unstable modes correspond to relative angles between the velocity of the
jet and momentum of the collective mode ~ pi/4. Our results suggest an
alternative mechanism for the description of the jet quenching phenomenon,
where the jet crossing the plasma loses energy exciting colored unstable modes.
In LHC this effect should be seen with an enhanced production of hadrons for
some specific values of their momenta and in certain directions of momenta
space.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:20:35 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Mannarelli",
"Massimo",
""
],
[
"Manuel",
"Cristina",
""
]
] |
0706.3988 | Vladimir Ivashchuk | S. B. Fadeev and V. D. Ivashchuk | 5-dimensional solution with acceleration and small variation of G | 4 pages, Latex, prepared for Proc. of the Russian summer
school-seminar Modern theoretical problems of gravitation and cosmology,
September 9-16, 2007, TSHPU, Kazan-Yalchik, Russia | null | null | IGC-PFUR/2007-06-1fi | gr-qc astro-ph | null | A 5-dimensional cosmological solution in the model with two 2-forms and two
``phantom'' scalar fields is considered. The model contains two dilatonic
coupling vectors obeying certain restrictions. It is shown that there exists a
time interval where accelerating expansion of ``our'' 3-dimensional space is
compatible with a small value of effective gravitational ``constant''
variation.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:21:22 GMT"
}
] | 2008-04-17T00:00:00 | [
[
"Fadeev",
"S. B.",
""
],
[
"Ivashchuk",
"V. D.",
""
]
] |
0706.3989 | Salvatore Antoci | S. Antoci, D.-E. Liebscher | Hans-Juergen Treder and the discovery of confinement in Einstein's
unified field theory | 11 pages, LaTeX | null | null | null | physics.hist-ph gr-qc | null | In the year 1957, when interest in Einstein's unified field theory was fading
away for lack of understanding of its physical content, Treder performed a
momentous critical analysis of the possible definitions of the electric
four-current in the theory. As an outcome of this scrutiny he was able to prove
by the E.I.H. method that properly defined point charges, appended at the
right-hand side of the field equation $R_{[[\mu\nu],\lambda]}=0$, interact
mutually with Coulomb-like forces, provided that a mutual force independent of
distance is present too. This unwanted, but unavoidable addition, could not but
lay further disbelief on the efforts initiated by Einstein and Schroedinger one
decade earlier. However in 1980 Treder himself recalled that the potential
$\phi=a/r+cr$, found by him in 1957, was the one used by particle physicists to
account phenomenologically for the spectrum of bound quark systems like mesons.
Exact solutions have later confirmed beyond any doubt that Einstein's unified
field theory does account in a simple way, already in classical form, for the
confinement of pole charges defined by the four-current first availed of by
Treder. In the present paper it is proposed, ad memoriam, a thorough
recollection of the article published by Treder in 1957, showing the way kept
by him to find what would have been later recognized as confinement in
Einstein's unified field theory.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:30:37 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Antoci",
"S.",
""
],
[
"Liebscher",
"D. -E.",
""
]
] |
0706.3990 | Jan Harm van der Walt | Jan Harm van der Walt | The order completion method for systems of nonlinear PDEs:
Pseudo-topological perspectives | 18 pages | null | null | UPWT 2007/07 | math.GM | null | By setting up appropriate uniform convergence structures, we are able to
reformulate the Order Completion Method of Oberguggenberger and Rosinger in a
setting that more closely resembles the usual topological constructions for
solving PDEs. As an application, we obtain existence and uniqueness results for
the solutions of arbitrary continuous, nonlinear PDEs.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:43:43 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"van der Walt",
"Jan Harm",
""
]
] |
0706.3991 | Riccardo Argurio | Riccardo Argurio, Cyril Closset | A Quiver of Many Runaways | 20+12 pages, 3 figures | JHEP 0709:080,2007 | 10.1088/1126-6708/2007/09/080 | null | hep-th | null | We study the quantum corrections to the moduli space of the quiver gauge
theory corresponding to regular and fractional D3-branes at the dP_1
singularity. We find that besides the known runaway behavior at the lowest step
of the duality cascade, there is a runaway direction along a mesonic branch at
every higher step of the cascade. Moreover, the algebra of the chiral operators
which obtain the large expectation values is such that we reproduce Altmann's
first order deformation of the dP_1 cone.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 09:56:05 GMT"
}
] | 2009-11-18T00:00:00 | [
[
"Argurio",
"Riccardo",
""
],
[
"Closset",
"Cyril",
""
]
] |
0706.3992 | Gandalf Lechner | Harald Grosse, Gandalf Lechner | Wedge-Local Quantum Fields and Noncommutative Minkowski Space | Version to appear in JHEP, 27 pages | JHEP 0711:012,2007 | 10.1088/1126-6708/2007/11/012 | null | hep-th math-ph math.MP | null | Within the setting of a recently proposed model of quantum fields on
noncommutative Minkowski spacetime, the consequences of the consistent
application of the proper, untwisted Poincare group as the symmetry group are
investigated. The emergent model contains an infinite family of fields which
are labelled by different noncommutativity parameters, and related to each
other by Lorentz transformations. The relative localization properties of these
fields are investigated, and it is shown that to each field one can assign a
wedge-shaped localization region of Minkowski space. This assignment is
consistent with the principles of covariance and locality, i.e. fields
localized in spacelike separated wedges commute.
Regarding the model as a non-local, but wedge-local, quantum field theory on
ordinary (commutative) Minkowski spacetime, it is possible to determine
two-particle S-matrix elements, which turn out to be non-trivial. Some partial
negative results concerning the existence of observables with sharper
localization properties are also obtained.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 10:17:59 GMT"
},
{
"version": "v2",
"created": "Fri, 26 Oct 2007 16:24:02 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Grosse",
"Harald",
""
],
[
"Lechner",
"Gandalf",
""
]
] |
0706.3993 | Itzhack Dana | Itzhack Dana and Vladislav Roitberg | Quantum Resonances and Ratchets in Free-Falling Frames | To appear in Physical Review E (Rapid Communications) | Physical Review E 76, 015201(R) (2007). | 10.1103/PhysRevE.76.015201 | null | nlin.CD | null | Quantum resonance (QR) is defined in the free-falling frame of the quantum
kicked particle subjected to gravity. The general QR conditions are derived.
They imply the rationality of the gravity parameter $\eta$, the kicking-period
parameter $\tau /(2\pi)$, and the quasimomentum $\beta$. Exact results are
obtained concerning wave-packet evolution for arbitrary periodic kicking
potentials in the case of integer $\tau /(2\pi)$ (the main QRs). It is shown
that a quantum ratchet generally arises in this case for resonant $\beta$. The
noninertial nature of the free-falling frame affects the ratchet by effectively
changing the kicking potential to one depending on $(\beta ,\eta)$. For a
simple class of initial wave packets, it is explicitly shown that the ratchet
characteristics are determined to a large extent by symmetry properties and by
number-theoretical features of $\eta$.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 10:24:28 GMT"
}
] | 2007-07-17T00:00:00 | [
[
"Dana",
"Itzhack",
""
],
[
"Roitberg",
"Vladislav",
""
]
] |
0706.3994 | Vitaly Vanchurin | Jin U Kang, Vitaly Vanchurin, Sergei Winitzki | Attractor scenarios and superluminal signals in k-essence cosmology | 27 pages, RevTeX4. Minor cosmetic changes, references added | Phys.Rev.D76:083511,2007 | 10.1103/PhysRevD.76.083511 | null | gr-qc astro-ph hep-ph hep-th | null | Cosmological scenarios with k-essence are invoked in order to explain the
observed late-time acceleration of the universe. These scenarios avoid the need
for fine-tuned initial conditions (the "coincidence problem") because of the
attractor-like dynamics of the k-essence field \phi. It was recently shown that
all k-essence scenarios with Lagrangians p=L(X)/\phi^2, necessarily involve an
epoch where perturbations of \phi propagate faster than light (the "no-go
theorem"). We carry out a comprehensive study of attractor-like cosmological
solutions ("trackers") involving a k-essence scalar field \phi and another
matter component. The result of this study is a complete classification of
k-essence Lagrangians that admit asymptotically stable tracking solutions,
among all Lagrangians of the form p=K(\phi)L(X) . Using this classification, we
select the class of models that describe the late-time acceleration and avoid
the coincidence problem through the tracking mechanism. An analogous "no-go
theorem" still holds for this class of models, indicating the existence of a
superluminal epoch. In the context of k-essence cosmology, the superluminal
epoch does not lead to causality violations. We discuss the implications of
superluminal signal propagation for possible causality violations in
Lorentz-invariant field theories.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 19:00:57 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 13:39:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kang",
"Jin U",
""
],
[
"Vanchurin",
"Vitaly",
""
],
[
"Winitzki",
"Sergei",
""
]
] |
0706.3995 | Modugno Michele | G. Barontini and M. Modugno | Dynamical instability and dispersion management of an attractive
condensate in an optical lattice | 5 pages, 4 figures | null | 10.1103/PhysRevA.76.041601 | null | cond-mat.other | null | We investigate the stability of an attractive Bose-Einstein condensate in a
moving 1D optical lattice in the presence of transverse confinement. By means
of a Bogoliubov linear stability analysis we find that the system is
dynamically unstable for low quasimomenta and becomes stable near the band
edge, in a specular fashion with respect to the repulsive case. For low
interactions the instability occurs via long wavelength excitations that are
not sufficient for spoiling the condensate coherence, producing instead an
oscillating density pattern both in real and momentum space. This behaviour is
illustrated by simulations for the expansion of the condensate in a moving
lattice.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:04:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Barontini",
"G.",
""
],
[
"Modugno",
"M.",
""
]
] |
0706.3996 | Tanay Dey Kumar | Tanay K. Dey, Sudipta Mukherji, Subir Mukhopadhyay, Swarnendu Sarkar | Phase transitions in higher derivative gravity and gauge theory:
R-charged black holes | 36 pages, 16 figures; v2: typos corrected, references added | JHEP 0709:026,2007 | 10.1088/1126-6708/2007/09/026 | null | hep-th | null | This is a continuation of our earlier work where we constructed a
phenomenologically motivated effective action of the boundary gauge theory at
finite temperature and finite gauge coupling on $S^3 \times S^1$. In this
paper, we argue that this effective action qualitatively reproduces the gauge
theory representing various bulk phases of R-charged black hole with
Gauss-Bonnet correction. We analyze the system both in canonical and grand
canonical ensemble.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 10:55:28 GMT"
},
{
"version": "v2",
"created": "Thu, 27 Sep 2007 16:52:27 GMT"
}
] | 2009-04-17T00:00:00 | [
[
"Dey",
"Tanay K.",
""
],
[
"Mukherji",
"Sudipta",
""
],
[
"Mukhopadhyay",
"Subir",
""
],
[
"Sarkar",
"Swarnendu",
""
]
] |
0706.3997 | L\'aszl\'o Borda | M. Sindel, L. Borda, J. Martinek, R. Bulla, J. Koenig, G. Schoen, S.
Maekawa, and J. von Delft | Kondo quantum dot coupled to ferromagnetic leads: Numerical
renormalization group study | 18 pages, 18 figures, accepted for publication in PRB | Phys. Rev. B 76, 045321 (2007) | 10.1103/PhysRevB.76.045321 | null | cond-mat.mes-hall cond-mat.str-el | null | We systematically study the influence of ferromagnetic leads on the Kondo
resonance in a quantum dot tuned to the local moment regime. We employ Wilson's
numerical renormalization group method, extended to handle leads with a spin
asymmetric density of states, to identify the effects of (i) a finite spin
polarization in the leads (at the Fermi-surface), (ii) a Stoner splitting in
the bands (governed by the band edges) and (iii) an arbitrary shape of the
leads density of states. For a generic lead density of states the quantum dot
favors being occupied by a particular spin-species due to exchange interaction
with ferromagnetic leads leading to a suppression and splitting of the Kondo
resonance. The application of a magnetic field can compensate this asymmetry
restoring the Kondo effect. We study both the gate-voltage dependence (for a
fixed band structure in the leads) and the spin polarization dependence (for
fixed gate voltage) of this compensation field for various types of bands.
Interestingly, we find that the full recovery of the Kondo resonance of a
quantum dot in presence of leads with an energy dependent density of states is
not only possible by an appropriately tuned external magnetic field but also
via an appropriately tuned gate voltage. For flat bands simple formulas for the
splitting of the local level as a function of the spin polarization and gate
voltage are given.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:03:57 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Sindel",
"M.",
""
],
[
"Borda",
"L.",
""
],
[
"Martinek",
"J.",
""
],
[
"Bulla",
"R.",
""
],
[
"Koenig",
"J.",
""
],
[
"Schoen",
"G.",
""
],
[
"Maekawa",
"S.",
""
],
[
"von Delft",
"J.",
""
]
] |
0706.3998 | Arif Shoshi | Misha Kozlov, Arif I. Shoshi and Bo-Wen Xiao | Fluctuation Effects on R_pA at High Energy | To appear in the proceedings of the Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 June,
2007 | null | null | BI-TP-2007-13, CU-TP-1179 | hep-ph | null | We discuss a new physical phenomenon for R_pA in the fixed coupling case, the
total gluon shadowing, which arises due to the effect of gluon number
fluctuations.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:17:01 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Kozlov",
"Misha",
""
],
[
"Shoshi",
"Arif I.",
""
],
[
"Xiao",
"Bo-Wen",
""
]
] |
0706.3999 | Eugenio R. Bezerra de Mello | R. de Lima Rodrigues, A. F. de Lima, E. R. Bezerra de Mello, V. B.
Bezerra | On Matrix Superpotential and Three-Component Normal Modes | 17 pages, no figure. Paper accepted for publication in Journal of
Physics A: Mathematical and Theoretical | J.Phys.A41:025401,2008 | 10.1088/1751-8113/41/2/025401 | null | hep-th | null | We consider the supersymmetric quantum mechanics (SUSY QM) with three-
component normal modes for the Bogomol'nyi-Prasad-Sommerfield (BPS) states. An
explicit form of the SUSY QM matrix superpotential is presented and the
corresponding three-component bosonic zero-mode eigenfunction is investigated.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:23:41 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Nov 2007 11:28:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Rodrigues",
"R. de Lima",
""
],
[
"de Lima",
"A. F.",
""
],
[
"de Mello",
"E. R. Bezerra",
""
],
[
"Bezerra",
"V. B.",
""
]
] |
0706.4000 | Boris Krippa | Boris Krippa | Effective field theory and cold Fermi gases near unitary limit | 13 pages, 3 figures, version accepted for publication | Phys.Rev.A75:053622,2007 | 10.1103/PhysRevA.75.053622 | null | cond-mat.supr-con nucl-th | null | We study a dynamics of ultracold Fermi-gases near the unitary limit in the
framework of Effective Field Theory. It is shown that, while one can obtain a
reasonable description of the universal proportionality constant both in the
narrow and the broad Feshbach resonance limits, the reguirement of the
reparametrisation invariance leads to appearance of the three body forces
needed to cancel the otherwise arising off-shell uncertainties. The size of the
unsertainties is estimated.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:31:30 GMT"
},
{
"version": "v2",
"created": "Wed, 14 Nov 2007 15:46:32 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Krippa",
"Boris",
""
]
] |
0706.4001 | Hideaki Maebashi | Hideaki Maebashi and Yasutami Takada | Pseudo-Quantum Criticality in Electron Liquids Exhibited in Expanded
Alkali Metals | 4 pages, 4 figures | null | null | null | cond-mat.other cond-mat.mtrl-sci | null | With paying special attention to the divergence in the compressibility
$\kappa$, we study the Coulombic screening in alkali metals to find singular
long-range fluctuations in the electronic polarization originating from this
divergence. As a consequence of this singularity, we predict the decrease of
the equilibration distance between ions against the increase of $r_s$ the
Wigner-Seitz radius of valence electrons, provided that the condition of $2r_c
< r_s < 4r_c$ is satisfied with $r_c$ the ion-core radius. This prediction is
in good quantitative agreement with the recent experiment on liquid Rb.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:43:00 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Maebashi",
"Hideaki",
""
],
[
"Takada",
"Yasutami",
""
]
] |
0706.4002 | Miles Simon | Miles Simon | Local results for flows whose speed or height satisfies a bound of the
form $\frac c t$ | This paper is chapter 7 of the author's Habilitation Thesis:"Ricci
flow of almost non-negatively curved three manifolds", Nov. 2006, University
of Freiburg, Germany | null | null | null | math.DG | null | In this paper we prove local results for solutions to the Ricci flow (heat
flow) whose speed (height) is bounded by $\frac c t$ for some time interval $ t
\in (0,T)$. These results are contained in chapter 7 of the author's
habilitation thesis, University of Freiburg, Germany, 2006.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 14:41:20 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Simon",
"Miles",
""
]
] |
0706.4003 | Anatoly Golub | A. Golub | Shot noise in the interacting resonance level model | 4 pages, 2 figures | null | 10.1103/PhysRevB.76.193307 | null | cond-mat.str-el | null | The shot noise power and the Fano factor of a spinless resonant level model
is calculated. The Coulomb interaction which in this model acts between the
lead electron and the impurity is considered in the first order approximation.
The logarithmic divergencies which appeared in the expressions for shot noise
and the transport current are removed by renormalization group analysis. It is
shown that Keldysh technique gives an adequate description of perturbation
theory results. By passing to the bosonized form of the resonance model it is
proven that in the strong interaction limit the tunnelling becomes irrelevant
and decreases.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:49:16 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 06:44:53 GMT"
}
] | 2013-05-29T00:00:00 | [
[
"Golub",
"A.",
""
]
] |
0706.4004 | Ahmed Ait Ali | Ahmed Ait Ali (CRAN), Fabien Michaut (CRAN), Francis Lepage (CRAN) | End-to-End Available Bandwidth Measurement Tools : A Comparative
Evaluation of Performances | null | IPS-MoMe 2006 IEEE /ACM International workshop on Internet
Performance, Simulation, Monitoring and Measurement, Autriche (27/02/2005) 13 | null | null | cs.NI | null | In recent years, there has been a strong interest in measuring the available
bandwidth of network paths. Several methods and techniques have been proposed
and various measurement tools have been developed and evaluated. However, there
have been few comparative studies with regards to the actual performance of
these tools. This paper presents a study of available bandwidth measurement
techniques and undertakes a comparative analysis in terms of accuracy,
intrusiveness and response time of active probing tools. Finally, measurement
errors and the uncertainty of the tools are analysed and overall conclusions
made.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:51:36 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Ali",
"Ahmed Ait",
"",
"CRAN"
],
[
"Michaut",
"Fabien",
"",
"CRAN"
],
[
"Lepage",
"Francis",
"",
"CRAN"
]
] |
0706.4005 | Anne Amy | Andrei Goncharov (LPL, ILP), Olivier Lopez (LPL), Anne Amy (LPL),
Fr\'ed\'eric Du Burck (LPL) | Absolute frequency measurements for hyperfine structure determination of
the R(26) 62-0 transition at 501.7 nm in molecular iodine | null | null | 10.1088/0026-1394/44/5/003 | null | physics.atom-ph | null | The absolute frequencies of the hyperfine components of the R(26) 62-0
transition in molecular iodine at 501.7 nm are measured for the first time with
an optical clockwork based on a femtosecond laser frequency comb generator. The
set-up is composed of an Ar+ laser locked to a hyperfine component of the R(26)
62-0 transition detected in a continuously pumped low-pressure cell (0.33 Pa).
The detected resonances show a linewidth of 45 kHz (half-width at
half-maximum). The uncertainty of the frequency measurement is estimated to be
250 Hz.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:57:16 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Goncharov",
"Andrei",
"",
"LPL, ILP"
],
[
"Lopez",
"Olivier",
"",
"LPL"
],
[
"Amy",
"Anne",
"",
"LPL"
],
[
"Burck",
"Frédéric Du",
"",
"LPL"
]
] |
0706.4006 | Dennis D. Dietrich | Dennis D. Dietrich and Gerald V. Dunne | Gutzwiller's Trace Formula and Vacuum Pair Production | 7 pages | J.Phys.A40:F825-F830,2007 | 10.1088/1751-8113/40/34/F01 | null | hep-th | null | We propose a new application of the Gutzwiller trace formula formalism, to
give a compact expression for the semiclassical vacuum pair production rate in
quantum electrodynamics, for general inhomogeneous electromagnetic background
fields.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 11:58:10 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Dietrich",
"Dennis D.",
""
],
[
"Dunne",
"Gerald V.",
""
]
] |
0706.4007 | emilien Azema | \'Emilien Azema (LMGC), F. Radja\"I (LMGC), R. Peyroux (LMGC), G.
Saussine (R&D - SNCF) | Transmission des forces dans un milieu compos\'e de grains non
sph\'eriques | null | null | null | null | physics.class-ph | null | We perform a detailed analysis of the contact force network in a dense
confined packing of pentagonal particles simulated by means of the contact
dynamics method. The effect of particle shape is evidenced by comparing the
data from pentagon packing and from a packing with identical characteristics
except for the circular shape of the particles. A counterintuitive finding of
this work is that, under steady shearing, the pentagon packing develops a lower
structural anisotropy than the disk packing. We show that this weakness is
compensated by a higher force anisotropy, leading to enhanced shear strength of
the pentagon packing. We revisit "strong" and "weak" force networks in the
pentagon packing, but our simulation data provide also evidence for a large
class of "very weak" forces carried mainly by vertex-to-edge contacts. The
strong force chains are mostly composed of edge-to-edge contacts with a marked
zig-zag aspect and a decreasing exponential probability distribution as in a
disk packing.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:03:41 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Azema",
"Émilien",
"",
"LMGC"
],
[
"RadjaÏ",
"F.",
"",
"LMGC"
],
[
"Peyroux",
"R.",
"",
"LMGC"
],
[
"Saussine",
"G.",
"",
"R&D - SNCF"
]
] |
0706.4008 | Ingemar Eriksson | Ingemar Eriksson | Conserved Matter Superenergy Currents for Orthogonally Transitive
Abelian G2 Isometry Groups | 15 pages | Class.Quant.Grav.24:4955-4968,2007 | 10.1088/0264-9381/24/20/004 | null | gr-qc | null | In a previous paper we showed that the electromagnetic superenergy tensor,
the Chevreton tensor, gives rise to a conserved current when there is a
hypersurface orthogonal Killing vector present. In addition, the current is
proportional to the Killing vector. The aim of this paper is to extend this
result to the case when we have a two-parameter Abelian isometry group that
acts orthogonally transitive on non-null surfaces. It is shown that for
four-dimensional Einstein-Maxwell theory with a source-free electromagnetic
field, the corresponding superenergy currents lie in the orbits of the group
and are conserved. A similar result is also shown to hold for the trace of the
Chevreton tensor and for the Bach tensor, and also in Einstein-Klein-Gordon
theory for the superenergy of the scalar field. This links up well with the
fact that the Bel tensor has these properties and the possibility of
constructing conserved mixed currents between the gravitational field and the
matter fields.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:07:22 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Eriksson",
"Ingemar",
""
]
] |
0706.4009 | Veronika Rehn-Sonigo | Anne Benoit (INRIA Rh\^one-Alpes, LIP), Veronika Rehn-Sonigo (INRIA
Rh\^one-Alpes, LIP), Yves Robert (INRIA Rh\^one-Alpes, LIP) | Multi-criteria scheduling of pipeline workflows | null | null | null | null | cs.DC | null | Mapping workflow applications onto parallel platforms is a challenging
problem, even for simple application patterns such as pipeline graphs. Several
antagonist criteria should be optimized, such as throughput and latency (or a
combination). In this paper, we study the complexity of the bi-criteria mapping
problem for pipeline graphs on communication homogeneous platforms. In
particular, we assess the complexity of the well-known chains-to-chains problem
for different-speed processors, which turns out to be NP-hard. We provide
several efficient polynomial bi-criteria heuristics, and their relative
performance is evaluated through extensive simulations.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 13:43:16 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 15:20:26 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Benoit",
"Anne",
"",
"INRIA Rhône-Alpes, LIP"
],
[
"Rehn-Sonigo",
"Veronika",
"",
"INRIA\n Rhône-Alpes, LIP"
],
[
"Robert",
"Yves",
"",
"INRIA Rhône-Alpes, LIP"
]
] |
0706.4010 | Ralf Schutzhold | Clovis Maia and Ralf Sch\"utzhold | Quantum toy model for black-hole back-reaction | 4 pages | Phys.Rev.D76:101502,2007 | 10.1103/PhysRevD.76.101502 | null | gr-qc | null | We propose a simple quantum field theoretical toy model for black hole
evaporation and study the back-reaction of Hawking radiation onto the classical
background. It turns out that the horizon is also ``pushed back'' in this
situation (i.e., the interior region shrinks) but this back-reaction is not
caused by energy conservation but by momentum balance. The effective heat
capacity and the induced entropy variation can have both signs -- depending on
the parameters of the model. PACS: 04.62.+v, 04.70.Dy.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:15:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Maia",
"Clovis",
""
],
[
"Schützhold",
"Ralf",
""
]
] |
0706.4011 | Marco Belan | Marco Belan, Sergio De Ponte, Daniela Tordella | Determination of density and concentration from fluorescent images of a
gas flow | New figures in portable .eps format | null | 10.1007/s00348-008-0493-5 | null | physics.flu-dyn | null | A fluorescent image analysis procedure to determine the distribution of
species concentration and density in a gas flow is proposed. The fluorescent
emission is due to the excitation of atoms/molecules of a gas that is
intercepted by an electron blade. The intensity of the fluorescent light is
proportional to the local number density of the gas. When the gas flow is a
mixture of different species, this proportionality can be exploited to extract
the contribution associated to the species from the spectral superposition
acquired by a digital camera. This yields a method that simultaneously reveals
species concentrations and mass density of the mixture. The procedure is
applied to two under-expanded sonic jets discharged into a different gas
ambient - Helium into Argon and Argon into Helium - to measure the
concentration and density distribution along the jet axis and across it. A
comparison with experimental and numerical results obtained by other authors
when observing under-expanded jets at different Mach numbers is made with the
density distribution along the axis of the jet. This density distribution
appears to be self-similar.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:32:30 GMT"
},
{
"version": "v2",
"created": "Tue, 3 Jul 2007 15:39:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Belan",
"Marco",
""
],
[
"De Ponte",
"Sergio",
""
],
[
"Tordella",
"Daniela",
""
]
] |
0706.4012 | Buisseret Fabien Mr | F. Brau, F. Buisseret | Existence of mesons after deconfinement | 14 pages, 3 figures; only the case T>T_c is discussed in v2 | Phys. Rev. C 76, 065212 (2007) | 10.1103/PhysRevC.76.065212 | null | hep-ph | null | We investigate the possibility for a quark-antiquark pair to form a bound
state at temperatures higher than the critical one ($T>T_c$), thus after
deconfinement. Our main goal is to find analytical criteria constraining the
existence of such mesons. Our formalism relies on a Schr\"{o}dinger equation
for which we study the physical consequences of both using the free energy and
the internal energy as potential term, assuming a widely accepted
temperature-dependent Yukawa form for the free energy and a recently proposed
nonperturbative form for the screening mass. We show that using the free energy
only allows for the 1S bottomonium to be bound above $T_c$, with a dissociation
temperature around $1.5\times T_c$. The situation is very different with the
internal energy, where we show that no bound states at all can exist in the
deconfined phase. But, in this last case, quasi-bound states could be present
at higher temperatures because of a positive barrier appearing in the
potential.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:26:21 GMT"
},
{
"version": "v2",
"created": "Wed, 24 Oct 2007 08:37:22 GMT"
}
] | 2008-01-07T00:00:00 | [
[
"Brau",
"F.",
""
],
[
"Buisseret",
"F.",
""
]
] |
0706.4013 | Ralph Kraft | R. P. Kraft, P. E. J. Nulsen, M. Birkinshaw, D. M. Worrall, R. F.
Penna, W. R. Forman, M. J. Hardcastle, C. Jones, and S. S. Murray | A Chandra Study of the Lobe/ISM Interactions Around the Inner Radio
Lobes of Centaurus A: Constraints on the Temperature Structure and Transport
Processes | 29 pages, 9 figures, 2 tables - accepted for publication in the
Astrophysical Journal | null | 10.1086/519830 | null | astro-ph | null | We present results from deeper {\em Chandra} observations of the southwest
radio lobe of Centaurus A, first described by Kraft et al. (2003). We find that
the sharp X-ray surface brightness discontinuity extends around $\sim$75% of
the periphery of the radio lobe, and detect significant temperature jumps in
the brightest regions of this discontinuity nearest to the nucleus. This
demonstrates that this discontinuity is indeed a strong shock which is the
result of an overpressure which has built up in the entire lobe over time.
Additionally, we demonstrate that if the mean free path for ions to transfer
energy and momentum to the electrons behind the shock is as large as the
Spitzer value, the electron and proton temperatures will not have equilibrated
along the SW boundary of the radio lobe where the shock is strongest. Thus the
proton temperature of the shocked gas could be considerably larger than the
observed electron temperature, and the total energy of the outburst
correspondingly larger as well. We investigate this using a simple
one-dimensional shock model for a two-fluid (proton/electron) plasma. We find
that for the thermodynamic parameters of the Cen A shock the electron
temperature rises rapidly from $\sim$0.29 keV (the temperature of the ambient
ISM) to $\sim$3.5 keV at which point heating from the protons is balanced by
adiabatic losses. The proton and electron temperatures do not equilibrate in a
timescale less than the age of the lobe. We note that the measured electron
temperature of similar features in other nearby powerful radio galaxies in poor
environments may considerably underestimate the strength and velocity of the
shock.
| [
{
"version": "v1",
"created": "Wed, 27 Jun 2007 12:28:28 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kraft",
"R. P.",
""
],
[
"Nulsen",
"P. E. J.",
""
],
[
"Birkinshaw",
"M.",
""
],
[
"Worrall",
"D. M.",
""
],
[
"Penna",
"R. F.",
""
],
[
"Forman",
"W. R.",
""
],
[
"Hardcastle",
"M. J.",
""
],
[
"Jones",
"C.",
""
],
[
"Murray",
"S. S.",
""
]
] |
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