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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.3014 | Christopher Gordon | Christopher Gordon and Roberto Trotta (Oxford) | Bayesian Calibrated Significance Levels Applied to the Spectral Tilt and
Hemispherical Asymmetry | 5 pages. V2: clarifying comments added in response to referee report.
Matches version to appear in MNRAS | Mon.Not.Roy.Astron.Soc.382:1859-1863,2007 | 10.1111/j.1365-2966.2007.12707.x | null | astro-ph gr-qc hep-ph hep-th | null | Bayesian model selection provides a formal method of determining the level of
support for new parameters in a model. However, if there is not a specific
enough underlying physical motivation for the new parameters it can be hard to
assign them meaningful priors, an essential ingredient of Bayesian model
selection. Here we look at methods maximizing the prior so as to work out what
is the maximum support the data could give for the new parameters. If the
maximum support is not high enough then one can confidently conclude that the
new parameters are unnecessary without needing to worry that some other prior
may make them significant. We discuss a computationally efficient means of
doing this which involves mapping p-values onto upper bounds of the Bayes
factor (or odds) for the new parameters. A p-value of 0.05 ($1.96\sigma$)
corresponds to odds less than or equal to 5:2 which is below the `weak' support
at best threshold. A p-value of 0.0003 ($3.6\sigma$) corresponds to odds of
less than or equal to 150:1 which is the `strong' support at best threshold.
Applying this method we find that the odds on the scalar spectral index being
different from one are 49:1 at best. We also find that the odds that there is
primordial hemispherical asymmetry in the cosmic microwave background are 9:1
at best.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 15:39:17 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 14:01:26 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Gordon",
"Christopher",
"",
"Oxford"
],
[
"Trotta",
"Roberto",
"",
"Oxford"
]
] |
0706.3015 | Manuel Bibes | Manuel Bibes and Agnes Barthelemy | Oxide spintronics | Invited review paper published in a Special Issue of IEEE
Transactions on Electron Devices on Spintronics | IEEE Trans. Electron. Devices 54, 1003 (2007) | 10.1109/TED.2007.894366 | null | cond-mat.mtrl-sci cond-mat.str-el | null | Concomitant with the development of metal-based spintronics in the late
1980's and 1990's, important advances were made on the growth of high-quality
oxide thin films and heterostructures. While this was at first motivated by the
discovery of high-temperature superconductivity in perovskite Cu oxides, this
technological breakthrough was soon applied to other transition metal oxides,
and notably mixed-valence manganites. The discovery of colossal
magnetoresistance in manganite films triggered an intense research activity on
these materials, but the first notable impact of magnetic oxides in the field
of spintronics was the use of such manganites as electrodes in magnetic tunnel
junctions, yielding tunnel magnetoresistance ratios one order of magnitude
larger than what had been obtained with transition metal electrodes. Since
then, the research on oxide spintronics has been intense with the latest
developments focused on diluted magnetic oxides and more recently on
multiferroics. In this paper, we will review the most important results on
oxide spintronics, emphasizing materials physics as well as spin-dependent
transport phenomena, and finally give some perspectives on how the flurry of
new magnetic oxides could be useful for next-generation spintronics devices.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:16:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bibes",
"Manuel",
""
],
[
"Barthelemy",
"Agnes",
""
]
] |
0706.3016 | Sergei Sharapov Dr | V.P. Gusynin, S.G. Sharapov, J.P. Carbotte | AC conductivity of graphene: from tight-binding model to 2+1-dimensional
quantum electrodynamics | 46 pages, ws-ijmpb, 7 EPS figures; final version published in IJMPB | Int.J.Mod.Phys.B21:4611-4658,2007 | 10.1142/S0217979207038022 | NSF-KITP-07-126 | cond-mat.mes-hall cond-mat.str-el hep-ph | null | We consider the relationship between the tight-binding Hamiltonian of the
two-dimensional honeycomb lattice of carbon atoms with nearest neighbor hopping
only and the 2+1 dimensional Hamiltonian of quantum electrodynamics which
follows in the continuum limit. We pay particular attention to the symmetries
of the free Dirac fermions including spatial inversion, time reversal, charge
conjugation and chirality. We illustrate the power of such a mapping by
considering the effect of the possible symmetry breaking which corresponds to
the creation of a finite Dirac mass, on various optical properties. In
particular, we consider the diagonal AC conductivity with emphasis on how the
finite Dirac mass might manifest itself in experiment. The optical sum rules
for the diagonal and Hall conductivities are discussed.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 15:58:56 GMT"
},
{
"version": "v2",
"created": "Tue, 27 Nov 2007 14:51:16 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gusynin",
"V. P.",
""
],
[
"Sharapov",
"S. G.",
""
],
[
"Carbotte",
"J. P.",
""
]
] |
0706.3017 | Jurij W Darewych | Mark Barham and Jurij W. Darewych | Relativistic Three-Fermion Wave Equations in Reformulated QED and
Relativistic Effects in Muonium Minus | 12 pages | null | null | null | physics.atom-ph physics.chem-ph | null | The variational method, within the Hamiltonian formalism of reformulated QED
is used to determine relativistic wave equations for a system of three fermions
of arbitrary mass interacting electromagnetically. The interaction kernels of
the equations are, in essence, the invariant $\mathcal{M}$ matrices in lowest
order. The equations are used to obtain relativistic $O(\alpha^2)$ corrections
to the non-relativistic ground state energy levels of the Muonium negative ion
($\mu^+ e^- e^-$) as well as of $\mathrm{Ps}^-$ and $\mathrm{H}^-$, using
approximate variational three-body wave functions. The results are compared
with other calculations, where available. The relativistic correction for
Mu$^-$ is found to be $-1.0773 \times 10^{-4}$ eV.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:02:51 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Barham",
"Mark",
""
],
[
"Darewych",
"Jurij W.",
""
]
] |
0706.3018 | Salvatore Capozziello | S. Capozziello, V.I. Man'ko, G. Marmo, C. Stornaiolo | Tomographic Representation of Minisuperspace Quantum Cosmology and
Noether Symmetries | 15 pages | Gen.Rel.Grav.40:2627-2647,2008 | 10.1007/s10714-008-0643-3 | null | gr-qc hep-th | null | The probability representation, in which cosmological quantum states are
described by a standard positive probability distribution, is constructed for
minisuperspace models selected by Noether symmetries. In such a case, the
tomographic probability distribution provides the classical evolution for the
models and can be considered an approach to select "observable" universes. Some
specific examples, derived from Extended Theories of Gravity, are worked out.
We discuss also how to connect tomograms, symmetries and cosmological
parameters.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:08:21 GMT"
},
{
"version": "v2",
"created": "Wed, 22 Aug 2007 14:10:58 GMT"
},
{
"version": "v3",
"created": "Wed, 2 Apr 2008 12:22:57 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Capozziello",
"S.",
""
],
[
"Man'ko",
"V. I.",
""
],
[
"Marmo",
"G.",
""
],
[
"Stornaiolo",
"C.",
""
]
] |
0706.3019 | Jocelyn Monroe | Jocelyn Monroe, Peter Fisher | Neutrino Backgrounds to Dark Matter Searches | 6 pages, 8 figures; publication version | Phys.Rev.D76:033007,2007 | 10.1103/PhysRevD.76.033007 | MIT/MKI-07-19 | astro-ph hep-ex nucl-ex | null | Neutrino coherent scattering cross sections can be as large as 10^{-39} cm^2,
while current dark matter experiments have sensitivities to WIMP coherent
scattering cross sections five orders of magnitude smaller; future experiments
plan to have sensitivities to cross sections as small as 10^{-48} cm^2. With
large target masses and few keV recoil energy detection thresholds, neutral
current coherent scattering of solar neutrinos becomes an irreducible
background in dark matter searches. In the current zero-background analysis
paradigm, neutrino coherent scattering will limit the achievable sensitivity to
dark matter scattering cross sections, at the level of 10^{-46} cm^2.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:08:52 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Jul 2007 16:23:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Monroe",
"Jocelyn",
""
],
[
"Fisher",
"Peter",
""
]
] |
0706.3020 | O. Stenull | Olaf Stenull and T. C. Lubensky | Unconventional elasticity in smectic-A elastomers | 12 pages, 6 figures | Phys. Rev. E 76, 011706 (2007) | 10.1103/PhysRevE.76.011706 | null | cond-mat.soft | null | We study two aspects of the elasticity of smectic-$A$ elastomers that make
these materials genuinely and qualitatively different from conventional
uniaxial rubbers. Under strain applied parallel to the layer normal, monodomain
smectic-$A$ elastomers exhibit a drastic change in Young's modulus above a
threshold strain value of about 3%, as has been measured in experiments by
Nishikawa and Finkelmann [Macromol. Chem. Phys. {\bf 200}, 312 (1999)]. Our
theory predicts that such strains induce a transition to a smectic-$C$-like
state and that it is this transition that causes the change in elastic modulus.
We calculate the stress-strain behavior as well as the tilt of the smectic
layers and the molecular orientation for strain along the layer normal, and we
compare our findings with the experimental data. We also study the
electroclinic effect in chiral smectic-$A^\ast$ elastomers. According to
experiments by Lehmann {\em et al}. [Nature {\bf 410}, 447 (2001)] and
K\"{o}hler {\em et al}. [Applied Physics A {\bf 80}, 381 (2003)], this effect
leads in smectic-$A^\ast$ elastomers to a giant or, respectively, at least very
large lateral electrostriction. Incorporating polarization into our theory, we
calculate the height change of smectic-$A^\ast$ elastomer films in response to
a lateral external electric field, and we compare this result to the
experimental findings.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:20:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Stenull",
"Olaf",
""
],
[
"Lubensky",
"T. C.",
""
]
] |
0706.3021 | Alexey Muranov | Eric Jaligot, Alexey Muranov, and Azadeh Neman | Independence property and hyperbolic groups | v3: 10 pages (11pt), a few typos corrected, minor rearrangements
(e.g. Fact 2.3 and Lemma 2.5); v2: 8 pages (10pt), a false statement in the
proof of Fact 2.4 is replaced with a true one; v1: 8 pages | null | 10.2178/bsl/1208358845 | null | math.LO math.GR | null | We prove that existentially closed $CSA$-groups have the independence
property. This is done by showing that there exist words having the
independence property relatively to the class of torsion-free hyperbolic
groups.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:35:08 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 17:20:20 GMT"
},
{
"version": "v3",
"created": "Fri, 23 Nov 2007 16:47:44 GMT"
}
] | 2022-03-28T00:00:00 | [
[
"Jaligot",
"Eric",
""
],
[
"Muranov",
"Alexey",
""
],
[
"Neman",
"Azadeh",
""
]
] |
0706.3022 | Ioana Serban | I. Serban and F.K. Wilhelm | Dynamical tunneling in macroscopic systems | 4 pages, 3 figures | Phys. Rev. Lett. 99, 137001 (2007) | 10.1103/PhysRevLett.99.137001 | null | cond-mat.supr-con | null | We investigate macroscopic dynamical quantum tunneling (MDQT) in the driven
Duffing oscillator, charateristic for Josephson junction physics and
nanomechanics. Under resonant conditions between stable coexisting states of
such systems we calculate the tunneling rate. In macroscopic systems coupled to
a heat bath, MDQT can be masked by driving-induced activation. We compare both
processes, identify conditions under which tunneling can be detected with
present day experimental means and suggest a protocol for its observation.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:43:22 GMT"
}
] | 2008-04-01T00:00:00 | [
[
"Serban",
"I.",
""
],
[
"Wilhelm",
"F. K.",
""
]
] |
0706.3023 | Cristina Volpe | A.B. Balantekin, C. Volpe, J. Welzel | Impact of the Neutrino Magnetic Moment on the Neutrino Fluxes and the
Electron Fraction in core-collapse Supernovae | 7 pages, 6 figures | JCAP0709:016,2007 | 10.1088/1475-7516/2007/09/016 | null | astro-ph | null | We explore the effect of the neutrino magnetic moment on neutrino scattering
with matter in a core-collapse Supernova. We study the impact both on the
neutrino fluxes and on the electron fraction. We find that sizeable
modifications require very large magnetic moments both for Dirac and Majorana
neutrinos.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:47:47 GMT"
},
{
"version": "v2",
"created": "Fri, 27 Jul 2007 16:13:06 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Balantekin",
"A. B.",
""
],
[
"Volpe",
"C.",
""
],
[
"Welzel",
"J.",
""
]
] |
0706.3024 | Michael Shapiro | Oliver Goodman and Michael Shapiro | On a generalization of Dehn's algorithm | 33 pages, 2 figures, credits Kambites and Otto, mentions new work in
progress | null | null | null | math.GR math.GT | null | Viewing Dehn's algorithm as a rewriting system, we generalise to allow an
alphabet containing letters which do not necessarily represent group elements.
This extends the class of groups for which the algorithm solves the word
problem to include nilpotent groups, many relatively hyperbolic groups
including geometrically finite groups and fundamental groups of certain
geometrically decomposable manifolds. The class has several nice closure
properties. We also show that if a group has an infinite subgroup and one of
exponential growth, and they commute, then it does not admit such an algorithm.
We dub these Cannon's algorithms.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:50:31 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 21:37:19 GMT"
},
{
"version": "v3",
"created": "Sat, 4 Aug 2007 21:14:10 GMT"
},
{
"version": "v4",
"created": "Tue, 15 Jan 2008 22:28:04 GMT"
}
] | 2008-01-16T00:00:00 | [
[
"Goodman",
"Oliver",
""
],
[
"Shapiro",
"Michael",
""
]
] |
0706.3025 | Thomas G. Rizzo | Thomas G. Rizzo | Contact Interactions and Resonance-Like Physics at Present and Future
Colliders from Unparticles | 20 pages, 10 figs; minor text changes, ref added; typos corrected | JHEP 0710:044,2007 | 10.1088/1126-6708/2007/10/044 | SLAC-PUB-12580 | hep-ph hep-ex hep-th | null | High scale conformal physics can lead to unusual unparticle stuff at our low
energies. In this paper we discuss how the exchange of unparticles between
Standard Model fields can lead to new contact interaction physics as well as a
pseudoresonance-like structure, an unresonance, that might be observable at the
Tevatron or LHC in, e.g., the Drell-Yan channel. The specific signatures of
this scenario are quite unique and can be used to easily identify this new
physics given sufficient integrated luminosity.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 16:53:54 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 14:57:49 GMT"
},
{
"version": "v3",
"created": "Tue, 11 Sep 2007 16:38:27 GMT"
},
{
"version": "v4",
"created": "Thu, 27 Sep 2007 14:34:38 GMT"
}
] | 2009-05-05T00:00:00 | [
[
"Rizzo",
"Thomas G.",
""
]
] |
0706.3026 | Silas Beane | Silas R. Beane, Thomas C. Luu, Kostas Orginos, Assumpta Parreno,
Martin J. Savage, Aaron Torok and Andre Walker-Loud | Precise Determination of the I=2 pipi Scattering Length from
Mixed-Action Lattice QCD | 20 pages, 7 figures | Phys.Rev.D77:014505,2008 | 10.1103/PhysRevD.77.014505 | null | hep-lat hep-ph | null | The I=2 pipi scattering length is calculated in fully-dynamical lattice QCD
with domain-wall valence quarks on the asqtad-improved coarse MILC
configurations (with fourth-rooted staggered sea quarks) at four light-quark
masses. Two- and three-flavor mixed-action chiral perturbation theory at
next-to-leading order is used to perform the chiral and continuum
extrapolations. At the physical charged pion mass, we find m_pi a_pipi(I=2) =
-0.04330 +- 0.00042, where the error bar combines the statistical and
systematic uncertainties in quadrature.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:01:45 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Beane",
"Silas R.",
""
],
[
"Luu",
"Thomas C.",
""
],
[
"Orginos",
"Kostas",
""
],
[
"Parreno",
"Assumpta",
""
],
[
"Savage",
"Martin J.",
""
],
[
"Torok",
"Aaron",
""
],
[
"Walker-Loud",
"Andre",
""
]
] |
0706.3027 | Olga Shekhovtsova | G. Pancheri, O.Shekhovtsova, G. Venanzoni | Final state radiation and a possibility to test a pion-photon
interaction model near two-pion threshold | 16 pages, 6 figures | J.Exp.Theor.Phys.106:470-480,2008 | 10.1134/S1063776108030072 | null | hep-ph | null | Final state radiation in the process $e^+e^-\to\pi^+\pi^-$ is considered for
the cuts used in the analysis of KLOE data at large angles. By means of a Monte
Carlo event generator FEVA, effects of non-pointlike behaviour of pions are
estimated in the framework of Resonance Perturbation Theory. An additional
complication related with the $\phi$ meson intermediate state is taken into
account and the corresponding contributions (the direct decay
$\phi\to\pi^+\pi^-\gamma$ and the double resonance decay
$\phi\to\rho^\pm\pi^\mp\to\pi^+\pi^-\gamma$) are added to FEVA. A method to
test effects of non-pointlike behaviour of pions in a model-independent way is
proposed.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:03:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pancheri",
"G.",
""
],
[
"Shekhovtsova",
"O.",
""
],
[
"Venanzoni",
"G.",
""
]
] |
0706.3028 | Moty Katzman | Mordechai Katzman, Gennady Lyubeznik, Wenliang Zhang | On the discreteness and rationality of F-jumping coefficients | null | null | null | null | math.AC math.AG | null | This paper studies the jumping coefficients of principal ideals of regular
local rings.
Recently M. Blickle, M. Mustata and K. Smith showed that, when $R$ is of
essentially finite type over a field and $F$-finite, bounded intervals contain
finitely many jumping coefficients and that those are rational. In a later
paper they extended these results to principal ideals of $F$-finite complete
regular local rings. The aim of this paper is to extend these results on the
discreteness and rationality of jumping coefficients to principal ideals of
arbitrary (i.e. not necessarily $F$-finite) excellent regular local rings
containing fields of positive characteristic.
Our proof uses a very different method: we do not use $D$-modules and instead
we analyze the modules of nilpotents elements in the injective hull or $R$
under some non-standard Frobenius actions. This new method undoubtedly holds a
potential for more applications.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:27:46 GMT"
},
{
"version": "v2",
"created": "Wed, 30 Jan 2008 11:54:43 GMT"
}
] | 2008-01-30T00:00:00 | [
[
"Katzman",
"Mordechai",
""
],
[
"Lyubeznik",
"Gennady",
""
],
[
"Zhang",
"Wenliang",
""
]
] |
0706.3029 | David M. Bradley | David M. Bradley | Using integral transforms to estimate higher order derivatives | 10 pages AMSLaTeX, 1 table, 1 figure | The American Mathematical Monthly, Vol. 107, No. 10, December
2000, pp. 923--931. [MR 1807002] (2001m:26002) | null | null | math.NA math.HO | null | Integral transformations are used to estimate high order derivatives of
various special functions. Applications are given to numerical integration,
where estimates of high order derivatives of the integrand are needed to
achieve bounds on the error. The main idea is to find a suitable integral
representation of the function whose derivatives are to be estimated,
differentiate repeatedly under the integral sign, and estimate the resulting
integral.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:42:07 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Bradley",
"David M.",
""
]
] |
0706.3030 | Charles-Philippe Lajoie | C.-P. Lajoie and P. Bergeron | A Comparative Study of Optical and Ultraviolet Effective Temperatures
for DA White Dwarfs from the IUE Archive | Manuscript, 36 pages, 11 figures, accepted for publication in ApJ | null | 10.1086/520926 | null | astro-ph | null | We present a comparative study of effective temperatures determined from the
hydrogen Balmer lines and from the UV energy distribution for 140 DA white
dwarfs drawn from the IUE archive. Our results indicate that the optical and UV
temperatures of the majority of stars below T~40,000 K and within ~75 pc are in
fairly good agreement given the uncertainties. At higher temperatures and/or
larger distances, however, significant discrepancies are observed. Several
mechanisms are investigated to account for these discrepancies including the
effect of interstellar reddening, the presence of metals in the photosphere,
and the existence of unresolved binary white dwarfs. The results of our
analysis reveal that wavelength-dependent extinction is the most natural
explanation for the observed temperature differences. We also attempt to
predict the differences in optical and UV temperatures expected from unresolved
degenerate binaries by performing an exhaustive simulation of composite model
spectra. In light of these simulations, we then discuss some known double
degenerates and identify new binary candidates by restricting our analysis to
stars located within 75 pc where the effect of interstellar reddening is
significantly reduced.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:35:29 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lajoie",
"C. -P.",
""
],
[
"Bergeron",
"P.",
""
]
] |
0706.3031 | Ning Jia | Ning Jia and Ezra Miller | Duality of antidiagonals and pipe dreams | 6 pages, 4 figures; v3=v2 = online published version: edited
background exposition. (Why v3 = v2? Metadata issues.) | S\'eminaire Lotharingien de Combinatoire, Issue 58 (2008), Article
B58e. (electronic) | null | null | math.CO | null | Weighted enumeration of reduced pipe dreams (or rc-graphs) results in a
combinatorial expression for Schubert polynomials. The duality between the set
of reduced pipe dreams and certain antidiagonals has important geometric
implications [A. Knutson and E. Miller, Gr\"obner geometry of Schubert
polynomials, Ann. Math. 161, 1245-1318]. The original proof of the duality was
roundabout, relying on the algebra of certain monomial ideals and a recursive
characterization of reduced pipe dreams. This paper provides a direct
combinatorial proof.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:46:59 GMT"
},
{
"version": "v2",
"created": "Mon, 26 May 2008 18:45:16 GMT"
},
{
"version": "v3",
"created": "Mon, 26 May 2008 21:33:51 GMT"
}
] | 2008-05-27T00:00:00 | [
[
"Jia",
"Ning",
""
],
[
"Miller",
"Ezra",
""
]
] |
0706.3032 | Carlos Guillermo Gim\'enez de Castro | C. G. Gim\'enez de Castro (1), A. C. V. Saraiva (1,2), J. E. R. Costa
(2) and C. L. Selhorst (1,2) ((1) CRAAM/EE, S\~ao Paulo, Brazil, (2) INPE,
S\~ao Jos\'e dos Campos, Brazil) | The Solar Radius in the EUV during the Cycle XXIII | accepted for publication in Astronomy & Astrophysics minor changes
introduced during review process | null | 10.1051/0004-6361:20078118 | null | astro-ph | null | Aims. To determine the solar transition region and coronal radius at EUV
wavelengths and its time evolution during Solar Cycle XXIII.
Methods. We use daily 30.4 and 17.1 nm images obtained by the Extreme
Ultraviolet Imager (EIT) aboard the SoHO satellite and derive the solar radius
by fitting a circle to the limb brightness ring.
Results. The weighted mean of the temporal series gives (967''.56 +/- 0''.04)
and (969''.54 +/- 0''.02) at 30.4 and 17.1 nm respectively. No significant
correlation was found with the solar cycle at any of the two wavelengths.
Conclusions. Since the temperature formation of the 30.4 nm line is between
(60 - 80) 10^3 K (Transition Region), the obtained result is bigger than that
derived from present atmospheric models. On the contrary this height is
compatible with radio models.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:52:17 GMT"
},
{
"version": "v2",
"created": "Tue, 2 Oct 2007 20:23:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"de Castro",
"C. G. Giménez",
""
],
[
"Saraiva",
"A. C. V.",
""
],
[
"Costa",
"J. E. R.",
""
],
[
"Selhorst",
"C. L.",
""
]
] |
0706.3033 | Songxue Chi | Songxue Chi, F. Ye, Pengcheng Dai, J. A. Fernandez-Baca, Q. Huang, J.
W. Lynn, E. W. Plummer, R. Mathieu, Y. Kaneko, and Y. Tokura | Effect of antiferromagnetic spin correlations on lattice distortion and
charge ordering in Pr$_{0.5}$Ca$_{1.5}$MnO$_{4}$ | 7 pages, 5 figures | Proc. Natl. Acad. Sci. USA (PNAS) 104, 11796-11801 (2007) | 10.1073/pnas.0704303104 | null | cond-mat.str-el | null | We use neutron scattering to study the lattice and magnetic structure of the
layered half-doped manganite Pr$_{0.5}$Ca$_{1.5}$MnO$_4$. On cooling from high
temperature, the system first becomes charge- and orbital- ordered (CO/OO) near
$T_{CO}=300$ K and then develops checkerboard-like antiferromagnetic (AF) order
below $T_{N}=130$ K. At temperatures above $T_{N}$ but below $T_{CO}$
($T_N<T<T_{CO}$), the appearance of short-range AF spin correlations suppresses
the CO/OO induced orthorhombic strain, contrasting with other half-doped
manganites, where AF order has no observable effect on the lattice distortion.
These results suggest that a strong spin-lattice coupling and the competition
between AF exchange and CO/OO ordering ultimately determines the
low-temperature properties of the system.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:53:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Chi",
"Songxue",
""
],
[
"Ye",
"F.",
""
],
[
"Dai",
"Pengcheng",
""
],
[
"Fernandez-Baca",
"J. A.",
""
],
[
"Huang",
"Q.",
""
],
[
"Lynn",
"J. W.",
""
],
[
"Plummer",
"E. W.",
""
],
[
"Mathieu",
"R.",
""
],
[
"Kaneko",
"Y.",
""
],
[
"Tokura",
"Y.",
""
]
] |
0706.3034 | Brant M. Johnson | PHENIX Collaboration, S. Afanasiev, et al | Enhancement of the dielectron continuum in sqrt{s_NN} = 200 GeV Au+Au
collisions | 344 authors from 52 institutions, 7 pages, 4 figures. Submitted to
Physical Review Letters. Plain text data tables for the points plotted in
figures for this and previous PHENIX publications are (or will be) publicly
available at http://www.phenix.bnl.gov/papers.html | null | null | null | nucl-ex | null | The PHENIX experiment has measured the dielectron continuum in sqrt{s_NN} =
200 GeV Au+Au collisions. In minimum bias collisions the dielectron yield in
the mass range between 150 and 750 MeV/c^2 is enhanced by a factor of 3.4 +/-
0.2(stat.) +/- 1.3(syst.) +/- 0.7(model) compared to the expectation from our
model of hadron decays. The integrated yield increases faster with the
centrality of the collisions than the number of participating nucleons,
suggesting emission from scattering processes in the hot and dense medium. The
continuum yield between the masses of the phi and the J/psi mesons is
consistent with expectations from correlated c-cbar production, though other
mechanisms are not ruled out.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:46:05 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"PHENIX Collaboration",
"",
""
],
[
"Afanasiev",
"S.",
""
]
] |
0706.3035 | Diego Munoz | Diego J. Munoz, Diego Mardones, Guido Garay, David Rebolledo, Kate
Brooks and Sylvain Bontemps | Massive Clumps in the NGC 6334 Star Forming Region | 16 pages, 11 figures, 4 tables. To appear in the Astrophysical
Journal | null | 10.1086/521206 | null | astro-ph | null | We report observations of dust continuum emission at 1.2 mm toward the star
forming region NGC 6334 made with the SEST SIMBA bolometer array. The
observations cover an area of $\sim 2$ square degrees with approximately
uniform noise. We detected 181 clumps spanning almost three orders of magnitude
in mass (3\Msun$-6\times10^3$ \Msun) and with sizes in the range 0.1--1.0 pc.
We find that the clump mass function $dN/d\log M$ is well fit with a power law
of the mass with exponent -0.6 (or equivalently $dN/dM \propto M^{-1.6}$). The
derived exponent is similar to those obtained from molecular line emission
surveys and is significantly different from that of the stellar initial mass
function. We investigated changes in the mass spectrum by changing the
assumptions on the temperature distribution of the clumps and on the
contribution of free-free emission to the 1.2 mm emission, and found little
changes on the exponent. The Cumulative Mass Distribution Function is also
analyzed giving consistent results in a mass range excluding the high-mass end
where a power-law fit is no longer valid. The masses and sizes of the clumps
observed in NGC 6334 indicate that they are not direct progenitors of stars and
that the process of fragmentation determines the distribution of masses later
on or occurs at smaller spatial scales. The spatial distribution of the clumps
in NGC 6334 reveals clustering which is strikingly similar to that exhibited by
young stars in other star forming regions. A power law fit to the surface
density of companions gives $\Sigma\propto \theta^{-0.62}$.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 17:56:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Munoz",
"Diego J.",
""
],
[
"Mardones",
"Diego",
""
],
[
"Garay",
"Guido",
""
],
[
"Rebolledo",
"David",
""
],
[
"Brooks",
"Kate",
""
],
[
"Bontemps",
"Sylvain",
""
]
] |
0706.3036 | Evgeny Plekhanov | Adolfo Avella, Ferdinando Mancini | The Hubbard model: bosonic excitations and zero-frequency constants | null | Physica C 408, 287 (2004) | 10.1016/j.physc.2004.02.156 | null | cond-mat.str-el cond-mat.supr-con | null | A fully self-consistent calculation of the bosonic dynamics of the Hubbard
model is developed within the Composite Operator Method. From one side we
consider a basic set of fermionic composite operators (Hubbard fields) and
calculate the retarded propagators. On the other side we consider a basic set
of bosonic composite operators (charge, spin and pair) and calculate the causal
propagators. The equations for the Green's functions (GF) (retarded and
causal), studied in the polar approximation, are coupled and depend on a set of
parameters not determined by the dynamics. First, the pair sector is
self-consistently solved together with the fermionic one and the zero-frequency
constants (ZFC) are calculated not assuming the ergodic value, but fixing the
representation of the GF in such a way to maintain the constrains required by
the algebra of the composite fields. Then, the scheme to compute the charge and
spin sectors, ZFCs included, is given in terms of the fermionic and pair
correlators.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 18:03:37 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Avella",
"Adolfo",
""
],
[
"Mancini",
"Ferdinando",
""
]
] |
0706.3037 | Kerry Soileau | Kerry Michael Soileau | Implicit function density computation | I'm no longer satisfied with my treatment of this topic | null | null | null | math.GM | null | If two random variables X and A are functionally related via f(X)=A for some
strictly monotone continuously differentiable function f:R->R, the distribution
of X may easily be computed from the distribution of A.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 18:10:20 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 00:24:03 GMT"
},
{
"version": "v3",
"created": "Fri, 16 Nov 2018 16:51:16 GMT"
},
{
"version": "v4",
"created": "Sun, 14 Aug 2022 14:03:52 GMT"
}
] | 2022-08-16T00:00:00 | [
[
"Soileau",
"Kerry Michael",
""
]
] |
0706.3038 | Umesh Vijayashanker | R. Prabhu, A. R. Usha Devi and G. Padmanabha | Separability of a family of one parameter W and GHZ multiqubit states
using Abe-Rajagopal q-conditional entropy approach | 7 pages, 5 ps figures, RevteX, Accepted for publication in Physical
Review A | Phys. Rev. A 76, 042337 (2007) | 10.1103/PhysRevA.76.042337 | null | quant-ph | null | We employ conditional Tsallis q entropies to study the separability of
symmetric one parameter W and GHZ multiqubit mixed states. The strongest
limitation on separability is realized in the limit q-->infinity, and is found
to be much superior to the condition obtained using the von Neumann conditional
entropy (q=1 case). Except for the example of two qubit and three qubit
symmetric states of GHZ family, the $q$-conditional entropy method leads to
sufficient - but not necessary - conditions on separability.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 18:17:48 GMT"
},
{
"version": "v2",
"created": "Tue, 11 Sep 2007 17:27:03 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Prabhu",
"R.",
""
],
[
"Devi",
"A. R. Usha",
""
],
[
"Padmanabha",
"G.",
""
]
] |
0706.3039 | Alejandro Uribe | D. Burns, V. Guillemin, A. Uribe | The spectral density function of a toric variety | 16 pages | null | null | null | math.SP math-ph math.MP | null | For a Kahler manifold (X, \omega) with a holomorphic line bundle L and metric
h such that the Chern form of L is \omega, the spectral measures are the
measures \mu_N = \sum |s_{N,i}|^2 \nu, where \{s_{N,i}\}_i is an
L^2-orthonormal basis for H^0(X, L^{\otimes N}), and \nu is Liouville measure.
We study the asymptotics in N of \mu_N for (X, L) a Hamiltonian toric manifold,
and give a precise expansion in terms of powers 1/N^j and data on the moment
polytope \Delta of the Hamiltonian torus K acting on X. In addition, for an
infinitesimal character k of K and the unique unit eigensection s_{Nk} for the
character Nk of the torus action on H^0(X, L^N), we give a similar expansion
for the measures \mu_{Nk} = |s_{Nk}|^2 \nu. A final remark shows that the
eigenbasis \{s_{k}, k \in \Delta \cap \mathbb{Z}^{\dim K} \} is a
Bohr-Sommerfeld basis in the sense of Tyurin. Some of the present results are
related to work of Shiffman, Tate and Zelditch. The present paper uses no
microlocal analysis, but rather an Euler-Maclaurin formula for Delzant
polytopes.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:03:16 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Burns",
"D.",
""
],
[
"Guillemin",
"V.",
""
],
[
"Uribe",
"A.",
""
]
] |
0706.3040 | Frank Vollmer | Juraj Topolancik, Rob Ilic, and Frank Vollmer | Experimental observation of strong photon localization in disordered
photonic crystal waveguides | first submitted to PRL on April 20th, 2007; 16 pages, 4 figures | null | 10.1103/PhysRevLett.99.253901 | null | physics.optics physics.gen-ph | null | We demonstrate experimentally that structural perturbations imposed on
highly-dispersive photonic crystal-based waveguides give rise to spectral
features that bear signatures of Anderson localization. Sharp resonances with
the effective Qs of over 30,000 are found in scattering spectra of disordered
waveguides. The resonances are observed in a ~20-nm bandwidth centered at the
cutoff of slowly-guided Bloch-modes. Their origin can be explained with
interference of coherently scattered electromagnetic waves which results in the
formation of a narrow impurity (or localization) band populated with spectrally
distinct quasistates. Standard photon localization criteria are fulfilled in
the localization band.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:03:45 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Topolancik",
"Juraj",
""
],
[
"Ilic",
"Rob",
""
],
[
"Vollmer",
"Frank",
""
]
] |
0706.3041 | Peter Gonthier | Sarah A. Story, Peter L. Gonthier and Alice K. Harding | Population synthesis of radio and gamma-ray millisecond pulsars from the
Galactic disk | 38 pages, 10 figures, accepted in ApJ - new version | Astrophys.J.671:713-726,2007 | 10.1086/521016 | null | astro-ph | null | We present results of a population synthesis of millisecond pulsars from the
Galactic disk. Excluding globular clusters, we model the spatial distribution
of millisecond pulsars by assuming their birth in the Galactic disk with a
random kick velocity and evolve them to the present within the Galactic
potential. We assume that normal and millisecond pulsars are standard candles
described with a common radio luminosity model that invokes a new relationship
between radio core and cone emission suggested by recent studies. In modeling
the radio emission beams, we explore the relativistic effects of time delay,
aberration and sweepback of the open field lines. While these effects are
essential in understanding pulse profiles, the phase-averaged flux is
adequately described without a relativistic model. We use a polar cap
acceleration model for the gamma-ray emission. We present the preliminary
results of our recent study and the implications for observing millisecond
pulsars with GLAST and AGILE.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:24:31 GMT"
},
{
"version": "v2",
"created": "Fri, 24 Aug 2007 01:02:23 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Story",
"Sarah A.",
""
],
[
"Gonthier",
"Peter L.",
""
],
[
"Harding",
"Alice K.",
""
]
] |
0706.3042 | Mickael Bourgoin | Nauman M. Qureshi, Mickael Bourgoin, Christophe Baudet, Alain
Cartellier, Yves Gagne | Turbulent transport of material particles: An experimental study of
finite size effects | null | null | 10.1103/PhysRevLett.99.184502 | null | physics.flu-dyn | null | We use an acoustic Lagrangian tracking technique, particularly adapted to
measurements in open flows, and a versatile material particles generator (in
the form of soap bubbles with adjustable size and density) to characterize
Lagrangian statistics of finite sized, neutrally bouyant, particles transported
in an isotropic turbulent flow of air. We vary the size of the particles in a
range corresponding to turbulent inertial scales and explore how the turbulent
forcing experienced by the particles depends on their size. We show that, while
the global shape of the intermittent acceleration probability density function
does not depend significantly on particle size, the acceleration variance of
the particles decreases as they become larger in agreement with the classical
scaling for the spectrum of Eulerian pressure fluctuations in the carrier flow.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:11:16 GMT"
},
{
"version": "v2",
"created": "Wed, 11 Jul 2007 15:50:14 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Qureshi",
"Nauman M.",
""
],
[
"Bourgoin",
"Mickael",
""
],
[
"Baudet",
"Christophe",
""
],
[
"Cartellier",
"Alain",
""
],
[
"Gagne",
"Yves",
""
]
] |
0706.3043 | David Lai | David K. Lai (UCSC), Jennifer A. Johnson (OSU), Michael Bolte (UCSC),
Sara Lucatello (INAF-OAPD) | Carbon and Strontium Abundances of Metal-Poor Stars | ApJ, Accepted | null | 10.1086/520949 | null | astro-ph | null | We present carbon and strontium abundances for 100 metal-poor stars measured
from R$\sim $7000 spectra obtained with the Echellette Spectrograph and Imager
at the Keck Observatory. Using spectral synthesis of the G-band region, we have
derived carbon abundances for stars ranging from [Fe/H]$=-1.3$ to
[Fe/H]$=-3.8$. The formal errors are $\sim 0.2$ dex in [C/Fe]. The strontium
abundance in these stars was measured using spectral synthesis of the resonance
line at 4215 {\AA}. Using these two abundance measurments along with the barium
abundances from our previous study of these stars, we show it is possible to
identify neutron-capture-rich stars with our spectra. We find, as in other
studies, a large scatter in [C/Fe] below [Fe/H]$ = -2$. Of the stars with
[Fe/H]$<-2$, 9$\pm$4% can be classified as carbon-rich metal-poor stars. The Sr
and Ba abundances show that three of the carbon-rich stars are
neutron-capture-rich, while two have normal Ba and Sr. This fraction of carbon
enhanced stars is consistent with other studies that include this metallicity
range.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:48:02 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lai",
"David K.",
"",
"UCSC"
],
[
"Johnson",
"Jennifer A.",
"",
"OSU"
],
[
"Bolte",
"Michael",
"",
"UCSC"
],
[
"Lucatello",
"Sara",
"",
"INAF-OAPD"
]
] |
0706.3044 | Paul Vojta | Paul Vojta | On McQuillan's "tautological inequality" and the Weyl-Ahlfors theory of
associated curves | 27 pages, amstex | null | null | null | math.CV math.AG | null | In 1941, L. Ahlfors gave another proof of a 1933 theorem of H. Cartan on
approximation to hyperplanes of holomorphic curves in P^n. Ahlfors' proof built
on earlier work of H. and J. Weyl (1938), and proved Cartan's theorem by
studying the associated curves of the holomorphic curve. This work has
subsequently been reworked by H.-H. Wu in 1970, using differential geometry, M.
Cowen and P. A. Griffiths in 1976, further emphasizing curvature, and by Y.-T.
Siu in 1987 and 1990, emphasizing meromorphic connections. This paper gives
another variation of the proof, motivated by successive minima as in the proof
of Schmidt's Subspace Theorem, and using McQuillan's "tautological inequality."
In this proof, essentially all of the analysis is encapsulated within a
modified McQuillan-like inequality, so that most of the proof primarily uses
methods of algebraic geometry, in particular flag varieties. A diophantine
conjecture based on McQuillan's inequality is also posed.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:58:42 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Vojta",
"Paul",
""
]
] |
0706.3045 | Mukremin Kilic | Mukremin Kilic, K. Z. Stanek, and M. H. Pinsonneault (Ohio State) | The Future is Now: the Formation of Single Low Mass White Dwarfs in the
Solar Neighborhood | ApJ published version | ApJ, 2007, 671, 761 | 10.1086/522228 | null | astro-ph | null | Low mass helium-core white dwarfs (M < 0.45 Msun) can be produced from
interacting binary systems, and traditionally all of them have been attributed
to this channel. However, a low mass white dwarf could also result from a
single star that experiences severe mass loss on the first ascent giant branch.
A large population of low mass He-core white dwarfs has been discovered in the
old metal-rich cluster NGC 6791. There is therefore a mechanism in clusters to
produce low mass white dwarfs without requiring binary star interactions, and
we search for evidence of a similar population in field white dwarfs. We argue
that there is a significant field population (of order half of the detected
systems) that arises from old metal rich stars which truncate their evolution
prior to the helium flash from severe mass loss. There is a consistent absence
of evidence for nearby companions in a large fraction of low mass white dwarfs.
The number of old metal-rich field dwarfs is also comparable with the
apparently single low mass white dwarf population, and our revised estimate for
the space density of low mass white dwarfs produced from binary interactions is
also compatible with theoretical expectations. This indicates that this channel
of stellar evolution, hitherto thought hypothetical only, has been in operation
in our own Galaxy for many billions of years. One strong implication of our
model is that single low mass white dwarfs should be good targets for planet
searches because they are likely to arise from metal-rich progenitors. We also
discuss other observational tests and implications, including the potential
impact on SN Ia rates and the frequency of planetary nebulae.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 16:35:59 GMT"
},
{
"version": "v2",
"created": "Thu, 13 Dec 2007 19:36:41 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Kilic",
"Mukremin",
"",
"Ohio State"
],
[
"Stanek",
"K. Z.",
"",
"Ohio State"
],
[
"Pinsonneault",
"M. H.",
"",
"Ohio State"
]
] |
0706.3046 | Sarbani Basu | Chia-Hsien Lin (Yale University), H.M. Antia (Tata Institute, Mumbai),
Sarbani Basu (Yale University) | Seismic study of the chemical composition of the solar convection zone | Accepted for publication in ApJ | null | 10.1086/520916 | null | astro-ph | null | Recent downward revision of solar heavy-element abundances using
three-dimensional atmospheric model has introduced serious discrepancies
between standard solar models and helioseismic inferences about solar
structure. In this paper, we investigate the possibility of determining the
heavy-element abundances using helioseismic inversion techniques with the hope
of providing an independent estimate. We use the adiabatic index, Gamma_1
(logarithmic partial derivative of pressure with respect to density at constant
entropy) as a probe to examine the effects of the total heavy-element
abundance, as well as the effects due to the abundance of individual elements.
Our inversion results show that the new, lower, abundance increases the
discrepancy between the Sun and the solar models.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:00:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Lin",
"Chia-Hsien",
"",
"Yale University"
],
[
"Antia",
"H. M.",
"",
"Tata Institute, Mumbai"
],
[
"Basu",
"Sarbani",
"",
"Yale University"
]
] |
0706.3047 | Alicia Soderberg | Alicia M. Soderberg (Caltech) | The Radio Properties of Type Ibc Supernovae | 8 pages, Proceedings for "Supernova 1987A: 20 Years After: Supernovae
and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W. Weiler, and R.
McCray | AIPConf.Proc.937:492-499,2007 | 10.1063/1.2803613 | null | astro-ph | null | Over the past few years, long-duration gamma-ray bursts (GRBs), including the
subclass of X-ray flashes (XRFs), have been revealed to be a rare variety of
Type Ibc supernova (SN Ibc). While all these events result from the death of
massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those
of ordinary Type Ibc SNe by many orders of magnitude. The observed diversity of
stellar death corresponds to large variations in the energy, velocity, and
geometry of the explosion ejecta. Using multi-wavelength (radio, optical,
X-ray) observations of the nearest GRBs, XRFs, and SNe Ibc, I show that while
GRBs and XRFs couple at least 10^48 erg to relativistic material, SNe Ibc
typically couple less than 10^48 erg to their fastest (albeit non-relativistic)
outflows. Specifically, I find that less than 3% of local SNe Ibc show any
evidence for association with a GRB or XRF. Recently, a new class of GRBs and
XRFs has been revealed which are under-luminous in comparison with the
statistical sample of GRBs. Owing to their faint high-energy emission, these
sub-energetic bursts are only detectable nearby (z < 0.1) and are likely 10
times more common than cosmological GRBs. In comparison with local SNe Ibc and
typical GRBs/XRFs, these explosions are intermediate in terms of both
volumetric rate and energetics. Yet the essential physical process that causes
a dying star to produce a GRB, XRF, or sub-energetic burst, and not just a SN,
remains a crucial open question. Progress requires a detailed understanding of
ordinary SNe Ibc which will be facilitated with the launch of wide-field
optical surveys in the near future.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:00:48 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Soderberg",
"Alicia M.",
"",
"Caltech"
]
] |
0706.3048 | Andisheh Mahdavi | A. Mahdavi (UVic), H. Hoekstra (UVic), A. Babul (UVic), D. Balam
(UVic), P. Capak (Caltech) | A Dark Core in Abell 520 | 10 pages, 5 figures, accepted for publication in the Astrophysical
Journal, higher resolution version at http://visav.phys.uvic.ca/~amahdavi | null | 10.1086/521383 | null | astro-ph | null | The rich cluster Abell 520 (z=0.201) exhibits truly extreme and puzzling
multi-wavelength characteristics. It may best be described as a "cosmic train
wreck." It is a major merger showing abundant evidence for ram pressure
stripping, with a clear offset in the gas distribution compared to the galaxies
(as in the bullet cluster 1E 0657-558). However, the most striking feature is a
massive dark core (721 h_70 M_sun/L_sun) in our weak lensing mass
reconstruction. The core coincides with the central X-ray emission peak, but is
largely devoid of galaxies. An unusually low mass to light ratio region lies
500 kpc to the east, and coincides with a shock feature visible in radio
observations of the cluster. Although a displacement between the X-ray gas and
the galaxy/dark matter distributions may be expected in a merger, a mass peak
without galaxies cannot be easily explained within the current collisionless
dark matter paradigm. Interestingly, the integrated gas mass fraction (~0.15),
mass-to-light ratio (220 h_70 M_sun/L_sun), and position on the X-ray
luminosity-temperature and mass-temperature relations are unremarkable. Thus
gross properties and scaling relations are not always useful indicators of the
dynamical state of clusters.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 05:41:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mahdavi",
"A.",
"",
"UVic"
],
[
"Hoekstra",
"H.",
"",
"UVic"
],
[
"Babul",
"A.",
"",
"UVic"
],
[
"Balam",
"D.",
"",
"UVic"
],
[
"Capak",
"P.",
"",
"Caltech"
]
] |
0706.3049 | Giovanni Villadoro | Giovanni Villadoro and Fabio Zwirner | Beyond Twisted Tori | 12 pages | Phys.Lett.B652:118-123,2007 | 10.1016/j.physletb.2007.07.002 | DFPD-07/TH/09 | hep-th | null | Exploiting the fact that Kaluza-Klein monopoles and the associated
generalized orbifold planes are sources for geometrical fluxes, omega, we show
that the standard constraint omega.omega=0, valid for superstring
compactifications on twisted tori, can be consistently relaxed. This leads to
novel possibilities for constructing superstring models with fluxes and
localized sources, as well as for stabilizing moduli. This also explains the
ten-dimensional origin of a family of N=4 gauged supergravities, whose
interpretation in type-IIA orientifold compactifications was lacking.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:36:46 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Villadoro",
"Giovanni",
""
],
[
"Zwirner",
"Fabio",
""
]
] |
0706.3050 | T. R. Mongan | T. R. Mongan | Dark matter from "strong gravity" - consistent with CRESST, CoGeNT and
DAMA/LIBRA | Updated to show consistency of dark matter candidate with CRESST,
CoGeNT and DAMA/LIBRA results | null | null | null | gr-qc astro-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Kelso, Hooper and Buckley [arXiv:1110.5338] found CRESST, CoGeNT and
DAMA/LIBRA results are consistent with 10 - 15 GeV dark matter particles.
Hennawi and Ostriker [arXiv:astro-ph/0108203] analyzed supermassive black hole
formation in the centers of galaxies, finding a best fit for dark matter
(self-interaction cross-section)/mass ratio = 0.02 cm^{2}/g, with round-off
error of 25%. Combining the Hennawi/Ostriker result with the "strong gravity"
model for dark matter [arXiv:0706.3050] requires dark matter particles with
mass between 10.5 GeV and 17.5 GeV, overlapping the Kelso/Hooper/Buckley dark
matter particle mass range.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:01:57 GMT"
},
{
"version": "v2",
"created": "Wed, 18 Nov 2009 21:19:57 GMT"
},
{
"version": "v3",
"created": "Wed, 14 Dec 2011 21:01:08 GMT"
}
] | 2011-12-16T00:00:00 | [
[
"Mongan",
"T. R.",
""
]
] |
0706.3051 | Peter Rabl | P. Rabl and P. Zoller | Molecular Dipolar Crystals as High Fidelity Quantum Memory for Hybrid
Quantum Computing | null | Phys. Rev. A 76, 042308 (2007) | 10.1103/PhysRevA.76.042308 | null | quant-ph cond-mat.other | null | We study collective excitations of rotational and spin states of an ensemble
of polar molecules, which are prepared in a dipolar crystalline phase, as a
candidate for a high fidelity quantum memory. While dipolar crystals are formed
in the high density limit of cold clouds of polar molecules under 1D and 2D
trapping conditions, the crystalline structure protects the molecular qubits
from detrimental effects of short range collisions. We calculate the lifetime
of the quantum memory by identifying the dominant decoherence mechanisms, and
estimate their effects on gate operations, when a molecular ensemble qubit is
transferred to a superconducting strip line cavity (circuit QED). In the case
rotational excitations coupled by dipole-dipole interactions we identify
phonons as the main limitation of the life time of qubits. We study specific
setups and conditions, where the coupling to the phonon modes is minimized.
Detailed results are presented for a 1D dipolar chain.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:03:04 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rabl",
"P.",
""
],
[
"Zoller",
"P.",
""
]
] |
0706.3052 | Brad Hansen | Brad M. S. Hansen and Travis Barman | Two Classes of Hot Jupiters | 35 pages, 16 figures in Preprint format. Submitted to ApJ | Astrophys.J.671:861-871,2007 | 10.1086/523038 | null | astro-ph | null | We identify two classes of transiting planet, based on their equilibrium
temperatures and Safronov numbers. We examine various possible explanations for
the dichotomy. It may reflect the influence of planet or planetesimal
scattering in determining when planetary migration stops. Another possibility
is that some planets lose more mass to evaporation than others. If this
evaporation process preferentially removes Helium from the planet, the
consequent reduction in the mean molecular weight may explain why some planets
have anomalously large radii.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:03:35 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Hansen",
"Brad M. S.",
""
],
[
"Barman",
"Travis",
""
]
] |
0706.3053 | Jay Dunn Mr. | Jay P. Dunn, D. Michael Crenshaw, S. B. Kraemer, and J. R. Gabel | A Survey of Intrinsic Absorption in Active Galaxies using the Far
Ultraviolet Spectroscopic Explorer | A higher resolution copy of the paper can be found at:
http://www.chara.gsu.edu/~dunn/ms.ps | Astron.J.134:1061-1071,2007 | 10.1086/520644 | null | astro-ph | null | We present a survey of 72 Seyfert galaxies and quasars observed by the it Far
Ultraviolet Spectroscopic Explorer (FUSE). We have determined that 72 of 253
available active galactic nuclei (AGN) targets are viable targets for detection
of intrinsic absorption lines. We examined these spectra for signs of intrinsic
absorption in the O VI doublet (lambda 1031.9, 1037.6) and Lyman beta (lambda
1025.7). The fraction of Seyfert 1 galaxies and low-redshift quasars at z <
0.15 that show evidence of intrinsic UV absorption is ~50%, which is slightly
lower than Crenshaw et al. (1999) found (60%) based on a smaller sample of
Seyfert 1 galaxies observed with the Hubble Space Telescope (HST). With this
new fraction we find a global covering factor of the absorbing gas with respect
to the central nucleus of ~0.4. Our survey is to date the largest searching for
intrinsic UV absorption with high spectral resolution, and is the first step
toward a more comprehensive study of intrinsic absorption in low-redshift AGN.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:09:12 GMT"
}
] | 2019-08-19T00:00:00 | [
[
"Dunn",
"Jay P.",
""
],
[
"Crenshaw",
"D. Michael",
""
],
[
"Kraemer",
"S. B.",
""
],
[
"Gabel",
"J. R.",
""
]
] |
0706.3054 | Johannes Skaar | {\O}yvind Lind-Johansen, Kristian Seip, and Johannes Skaar | The perfect lens on a finite bandwidth | null | J. Math. Phys. 50, 012908 (2009) | 10.1063/1.3068751 | null | physics.optics | null | The resolution associated with the so-called perfect lens of thickness $d$ is
$-2\pi d/\ln(|\chi+2|/2)$. Here the susceptibility $\chi$ is a Hermitian
function in $H^2$ of the upper half-plane, i.e., a $H^2$ function satisfying
$\chi(-\omega)=\bar{\chi(\omega)}$. An additional requirement is that the
imaginary part of $\chi$ be nonnegative for nonnegative arguments. Given an
interval $I$ on the positive half-axis, we compute the distance in
$L^\infty(I)$ from a negative constant to this class of functions. This result
gives a surprisingly simple and explicit formula for the optimal resolution of
the perfect lens on a finite bandwidth.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:13:57 GMT"
}
] | 2009-03-24T00:00:00 | [
[
"Lind-Johansen",
"Øyvind",
""
],
[
"Seip",
"Kristian",
""
],
[
"Skaar",
"Johannes",
""
]
] |
0706.3055 | Virginie Charette | Thierry Barbot, Virginie Charette, Todd Drumm, William M. Goldman and
Karin Melnick | A primer on the (2+1) Einstein universe | 56 pages, 6 figures | in "Recent Developments in Pseudo-Riemannian Geometry", European
Mathematical Society, (2008), 179--230 | null | null | math.DG | null | The Einstein universe is the conformal compactification of Minkowski space.
It also arises as the ideal boundary of anti-de Sitter space. The purpose of
this article is to develop the synthetic geometry of the Einstein universe in
terms of its homogeneous submanifolds and causal structure, with particular
emphasis on dimension $2 + 1$, in which there is a rich interplay with
symplectic geometry.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:17:24 GMT"
}
] | 2011-07-12T00:00:00 | [
[
"Barbot",
"Thierry",
""
],
[
"Charette",
"Virginie",
""
],
[
"Drumm",
"Todd",
""
],
[
"Goldman",
"William M.",
""
],
[
"Melnick",
"Karin",
""
]
] |
0706.3056 | Hans-Thomas Janka | H.-Th. Janka, A. Marek, and F.-S. Kitaura (MPI for Astrophysics,
Garching) | Neutrino-driven explosions twenty years after SN1987A | 11 pages, 6 figures; review proceeding for "Supernova 1987A: 20 Years
After: Supernovae and Gamma-Ray Bursters" AIP, New York, eds. S. Immler, K.W.
Weiler, and R. McCray | AIPConf.Proc.937:144-154,2007 | 10.1063/1.2803554 | null | astro-ph | null | The neutrino-heating mechanism remains a viable possibility for the cause of
the explosion in a wide mass range of supernova progenitors. This is
demonstrated by recent two-dimensional hydrodynamic simulations with detailed,
energy-dependent neutrino transport. Neutrino-driven explosions were not only
found for stars in the range of 8-10 solar masses with ONeMg cores and in case
of the iron core collapse of a progenitor with 11 solar masses, but also for a
``typical'' progenitor model of 15 solar masses. For such more massive stars,
however, the explosion occurs significantly later than so far thought, and is
crucially supported by large-amplitude bipolar oscillations due to the
nonradial standing accretion shock instability (SASI), whose low (dipole and
quadrupole) modes can develop large growth rates in conditions where convective
instability is damped or even suppressed. The dominance of low-mode deformation
at the time of shock revival has been recognized as a possible explanation of
large pulsar kicks and of large-scale mixing phenomena observed in supernovae
like SN 1987A.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:21:43 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Janka",
"H. -Th.",
"",
"MPI for Astrophysics,\n Garching"
],
[
"Marek",
"A.",
"",
"MPI for Astrophysics,\n Garching"
],
[
"Kitaura",
"F. -S.",
"",
"MPI for Astrophysics,\n Garching"
]
] |
0706.3057 | Ashkan Nikeghbali | Paul Bourgade, Ashkan Nikeghbali and Alain Rouault | The characteristic polynomial on compact groups with Haar measure : some
equalities in law | null | null | null | null | math.PR math-ph math.MP | null | This note presents some equalities in law for $Z_N:=\det(\Id-G)$, where $G$
is an element of a subgroup of the set of unitary matrices of size $N$, endowed
with its unique probability Haar measure. Indeed, under some general
conditions, $Z_N$ can be decomposed as a product of independent random
variables, whose laws are explicitly known. Our results can be obtained in two
ways : either by a recursive decomposition of the Haar measure or by previous
results by Killip and Nenciu on orthogonal polynomials with respect to some
measure on the unit circle. This latter method leads naturally to a study of
determinants of a class of principal submatrices.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:37:40 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Bourgade",
"Paul",
""
],
[
"Nikeghbali",
"Ashkan",
""
],
[
"Rouault",
"Alain",
""
]
] |
0706.3058 | Pablo D. Esquinazi | J. C. Gonz\'alez, M. Mu\~noz, N. Garc\'ia, J. Barzola-Quiquia, D.
Spoddig, K. Schindler, P. Esquinazi | Size Effects in the Magnetoresistance of Graphite: Absence of
Magnetoresistance in Micrometer size Samples | 4 pages, 3 figures | Phys. Rev. Lett. 99, 216601 (2007) | 10.1103/PhysRevLett.99.216601 | null | cond-mat.mes-hall cond-mat.mtrl-sci | null | We present a study of the magnetoresistance of highly oriented pyrolytic
graphite (HOPG) as a function of the sample size. Our results show
unequivocally that the magnetoresistance reduces with the sample size even for
samples of hundreds of micrometers size. This sample size effect is due the
large mean free path and Fermi wavelength of carriers in graphite and may
explain the observed practically absence of magnetoresistance in micrometer
confined small graphene samples where quantum effects should be at hand. These
were not taken into account in the literature yet and ask for a revision of
experimental and theoretical work on graphite.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 20:53:29 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"González",
"J. C.",
""
],
[
"Muñoz",
"M.",
""
],
[
"García",
"N.",
""
],
[
"Barzola-Quiquia",
"J.",
""
],
[
"Spoddig",
"D.",
""
],
[
"Schindler",
"K.",
""
],
[
"Esquinazi",
"P.",
""
]
] |
0706.3059 | Boris Kopeliovich | B.Z. Kopeliovich, H.-J. Pirner, I.K. Potashnikova and Ivan Schmidt | Jet lag effect and leading hadron production | 11 pages, 5 figures | Phys.Lett.B662:117-122,2008 | 10.1016/j.physletb.2008.02.061 | USM-TH-213 | hep-ph nucl-th | null | We propose a solution for the long standing puzzle of a too steeply falling
fragmentation function for a quark fragmenting into a pion, calculated by
Berger [1] in the Born approximation. Contrary to the simple anticipation that
gluon resummation worsens the problem, we find good agreement with data. Higher
quark Fock states slow down the quark, an effect which we call jet lag. It can
be also expressed in terms of vacuum energy loss. As a result, the space-time
development of the jet shrinks and the $z$-dependence becomes flatter than in
the Born approximation. The space-time pattern is also of great importance for
in-medium hadronization.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:00:23 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kopeliovich",
"B. Z.",
""
],
[
"Pirner",
"H. -J.",
""
],
[
"Potashnikova",
"I. K.",
""
],
[
"Schmidt",
"Ivan",
""
]
] |
0706.3060 | Eric Darve | Erich Elsen, V. Vishal, Mike Houston, Vijay Pande, Pat Hanrahan, Eric
Darve | N-Body Simulations on GPUs | null | null | null | null | cs.CE cs.DC | null | Commercial graphics processors (GPUs) have high compute capacity at very low
cost, which makes them attractive for general purpose scientific computing. In
this paper we show how graphics processors can be used for N-body simulations
to obtain improvements in performance over current generation CPUs. We have
developed a highly optimized algorithm for performing the O(N^2) force
calculations that constitute the major part of stellar and molecular dynamics
simulations. In some of the calculations, we achieve sustained performance of
nearly 100 GFlops on an ATI X1900XTX. The performance on GPUs is comparable to
specialized processors such as GRAPE-6A and MDGRAPE-3, but at a fraction of the
cost. Furthermore, the wide availability of GPUs has significant implications
for cluster computing and distributed computing efforts like Folding@Home.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:02:14 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Elsen",
"Erich",
""
],
[
"Vishal",
"V.",
""
],
[
"Houston",
"Mike",
""
],
[
"Pande",
"Vijay",
""
],
[
"Hanrahan",
"Pat",
""
],
[
"Darve",
"Eric",
""
]
] |
0706.3061 | Ilya Shkrob | Ilya A. Shkrob (ANL), Ross E. Larsen, William J. Glover, Benjamin J.
Schwartz (UCLA) | Pump-probe polarized transient hole burning (PTHB) dynamics of hydrated
electron revisited | 10 pages + 3 figures + supplement, will be submitted shortly to Chem.
Phys. Lett | null | 10.1016/j.cplett.2008.11.004 | null | physics.chem-ph | null | Femtosecond PTHB spectroscopy was expected to demonstrate the existence of
distinct s-p absorption subbands originating from the three nondegenerate
p-like excited states of hydrated electron in anisotropic solvation cavity. Yet
no conclusive experimental evidence either for this subband structure or the
reorientation of the cavity on the picosecond time scale has been obtained. We
demonstrate that rapid reorientation of s-p transition dipole moments in
response to small scale motion of water molecules is the likely culprit. The
polarized bleach is shown to be too small and too short lived to be observed
reliably on the sub-picosecond time scale.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:07:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Shkrob",
"Ilya A.",
"",
"ANL"
],
[
"Larsen",
"Ross E.",
"",
"UCLA"
],
[
"Glover",
"William J.",
"",
"UCLA"
],
[
"Schwartz",
"Benjamin J.",
"",
"UCLA"
]
] |
0706.3062 | Nevin N. Weinberg | Nevin N. Weinberg (UC Berkeley), Lars Bildsten (KITP, UCSB) | Carbon Detonation and Shock-Triggered Helium Burning in Neutron Star
Superbursts | 11 pages, 11 figures, accepted to ApJ; discussion about onset of
detonation discussed in new detail, including a new figure | null | 10.1086/522111 | null | astro-ph | null | The strong degeneracy of the 12C ignition layer on an accreting neutron star
results in a hydrodynamic thermonuclear runaway, in which the nuclear heating
time becomes shorter than the local dynamical time. We model the resulting
combustion wave during these superbursts as an upward propagating detonation.
We solve the reactive fluid flow and show that the detonation propagates
through the deepest layers of fuel and drives a shock wave that steepens as it
travels upward into lower density material. The shock is sufficiently strong
upon reaching the freshly accreted H/He layer that it triggers unstable 4He
burning if the superburst occurs during the latter half of the regular Type I
bursting cycle; this is likely the origin of the bright Type I precursor bursts
observed at the onset of superbursts. The cooling of the outermost shock-heated
layers produces a bright, ~0.1s, flash that precedes the Type I burst by a few
seconds; this may be the origin of the spike seen at the burst onset in 4U
1820-30 and 4U 1636-54, the only two bursts observed with RXTE at high time
resolution. The dominant products of the 12C detonation are 28Si, 32S, and
36Ar. Gupta et al. showed that a crust composed of such intermediate mass
elements has a larger heat flux than one composed of iron-peak elements and
helps bring the superburst ignition depth into better agreement with values
inferred from observations.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 19:37:54 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Aug 2007 00:20:30 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Weinberg",
"Nevin N.",
"",
"UC Berkeley"
],
[
"Bildsten",
"Lars",
"",
"KITP, UCSB"
]
] |
0706.3063 | Mukund Vasudevan | Mukund Vasudevan, Amy Shen, Bamin Khomami, and Radhakrishna
Sureshkumar | Self-similar shear-thickening behavior in CTAB/NaSal surfactant
solutions | 27 pages, 17 figures | null | 10.1122/1.2833594 | null | physics.flu-dyn | null | The effect of salt concentration Cs on the critical shear rate required for
the onset of shear thickening and apparent relaxation time of the
shear-thickened phase, has been investigated systematically for dilute
CTAB/NaSal solutions. Experimental data suggest a self-similar behavior of the
critical shear rate and relaxation time as functions of Cs. Specifically, the
former ~ Cs^(-6) whereas the latter ~ Cs^(6) such that an effective Weissenberg
number for the onset of the shear thickened phase is only weakly dependent on
Cs. A procedure has been developed to collapse the apparent shear viscosity
versus shear rate data obtained for various values of Cs into a single master
curve. The effect of Cs on the elastic modulus and mesh size of the
shear-induced gel phase for different surfactant concentrations is discussed.
Experiments performed using different flow cells (Couette and cone-and-plate)
show that the critical shear rate, relaxation time and the maximum viscosity
attained are geometry-independent. The elastic modulus of the gel phase
inferred indirectly by employing simplified hydrodynamic instability analysis
of a sheared gel-fluid interface is in qualitative agreement with that
predicted for an entangled phase of living polymers. A qualitative mechanism
that combines the effect of Cs on average micelle length and Debye parameter
with shear-induced configurational changes of rod-like micelles is proposed to
rationalize the self-similarity of SIS formation.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:40:35 GMT"
},
{
"version": "v2",
"created": "Mon, 17 Dec 2007 22:55:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Vasudevan",
"Mukund",
""
],
[
"Shen",
"Amy",
""
],
[
"Khomami",
"Bamin",
""
],
[
"Sureshkumar",
"Radhakrishna",
""
]
] |
0706.3064 | Luca Amendola | Luca Amendola (INAF/OAR, Roma, Italy), Marco Baldi
(Max-Planck-Institut f. Astrophysics, Garching, Germany), Christof Wetterich
(Institute for Theoretical Physics, Heidelberg, Germany) | Growing Matter | 6 pages | Phys.Rev.D78:023015,2008 | 10.1103/PhysRevD.78.023015 | null | astro-ph hep-ph hep-th | null | We investigate quintessence cosmologies with a matter component consisting of
particles with an increasing mass. While negligible in early cosmology, the
appearance of a growing matter component has stopped the evolution of the
cosmon field at a redshift around six. In turn, this has triggered the
accelerated expansion of the Universe. We propose to associate growing matter
with neutrinos. Then the presently observed dark energy density and its
equation of state are determined by the neutrino mass.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 21:46:15 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Amendola",
"Luca",
"",
"INAF/OAR, Roma, Italy"
],
[
"Baldi",
"Marco",
"",
"Max-Planck-Institut f. Astrophysics, Garching, Germany"
],
[
"Wetterich",
"Christof",
"",
"Institute for Theoretical Physics, Heidelberg, Germany"
]
] |
0706.3065 | Marcos Rodriguez Cardoso | M. C. Rodriguez | Double Chargino Production in $e^{-}e^{-}$ scattering | 9 pages, 9 figures, Talk given at CTP symposium on Supersymmetry at
LHC: Theoretical and Experimental Perspectives, The British University in
Egypt, Cairo, Egypt, 11-14 March 2007 | Int.J.Mod.Phys.A22:6080-6088,2007 | 10.1142/S0217751X07039250 | null | hep-ph hep-ex | null | We point out the production of the charginos and neutralinos in
electron-electron process in several supersymmetric models, in order to show
that the International Linear Collider can discover double charged charginos if
these particles really exist in nature.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 22:04:02 GMT"
}
] | 2010-11-03T00:00:00 | [
[
"Rodriguez",
"M. C.",
""
]
] |
0706.3066 | John Scales | Nathan S. Greeney and John A. Scales | Dielectric microscopy with submillimeter resolution | null | Applied Physics Letters, 91, 222909 (2007) | 10.1063/1.2818674 | null | cond-mat.soft cond-mat.mtrl-sci | null | In analogy with optical near-field scanning methods, we use tapered
dielectric waveguides as probes for a millimeter wave vector network analyzer.
By scanning thin samples between two such probes we are able to map the
spatially varying dielectric properties of materials with sub-wavelength
resolution; using a 150 GHz probe in transmision mode we see spatial resolution
of around 500 microns. We have applied this method to a variety of highly
heterogeneous materials. Here we show dielectric maps of granite and oil shale.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 22:04:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Greeney",
"Nathan S.",
""
],
[
"Scales",
"John A.",
""
]
] |
0706.3067 | Evgeni Gabev E | E. E. Gabev (1), Evgeni B. Gabev (2), E. E. Gabev Jr. (1), M. V.
Bogoeva (3) ((1) Institute of Experimental Pathology and Parasitology,
Bulgarian Academy of Sciences (2) Medical University, Sofia, Bulgaria, (3)
Institute of Zoology, Bulgarian Academy of Sciences, Sofia, Bulgaria) | Fitting analysis provides further evidence for eradication of hiv/aids
infection under combined liposome drug delivery treatment | 3 pages, 1 figure. Available at: http://www.geocities.com/hivaidsbg/ | Drug Delivery Systems and Sciences (UK). 2003, volume 3, No 2, pp.
49-51 | null | null | q-bio.TO | null | It is now evident that the commonly accepted strategy for treatment of
HIV/AIDS by highly active antiretroviral therapy (HAART) will not lead to
eradication of HIV in a reasonable time. This is straightforward from the
typical exponential viral load decay upon treatment revealing initial
considerable but incomplete reduction of plasma HIV RNA with subsequent low
level HIV persistence even in patients on effective antiretroviral therapy.
Here we show that the viral load follows a simple zero trend linear regression
line under different treatment approach recently proposed by us. This
unambiguously indicates a whole body HIV eradication in reasonable time.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 22:09:58 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Gabev",
"E. E.",
""
],
[
"Gabev",
"Evgeni B.",
""
],
[
"Gabev",
"E. E.",
"Jr."
],
[
"Bogoeva",
"M. V.",
""
]
] |
0706.3068 | Nick Seymour | Nick Seymour (1,2), Brigitte Rocca-Volmerange (1,3), Valerie de
Lapparent (1) ((1) Institut d'Astrophysique de Paris, (2) Spitzer Science
Center, (3) Universite Paris-Sud) | A 12um ISOCAM Survey of the ESO-Sculptor Field: Data Reduction and
Analysis | 12 pages, 7 figures, figure 1 modified from journal version for size,
accepted for publication in A&A, includes psfig.sty | null | 10.1051/0004-6361:20065218 | null | astro-ph | null | We present a detailed reduction of a mid-infrared 12um (LW10 filter) ISOCAM
open time observation performed on the ESO-Sculptor Survey field (Arnouts et
al. 1997). A complete catalogue of 142 sources (120 galaxies and 22 stars),
detected with high significance (equivalent to 5sigma), is presented above an
integrated flux density of 0.24mJy. Star/galaxy separation is performed by a
detailed study of colour-colour diagrams. The catalogue is complete to 1mJy and
below this flux density the incompleteness is corrected using two independent
methods. The first method uses stars and the second uses optical counterparts
of the ISOCAM galaxies; these methods yield consistent results. We also apply
an empirical flux density calibration using stars in the field. For each star,
the 12um flux density is derived by fitting optical colours from a multi-band
chi^2 to stellar templates (BaSel-2.0) and using empirical optical-IR
colour-colour relations. This article is a companion analysis to
Rocca-Volmerange 2007 et al. where the 12um faint galaxy counts are presented
and analysed by galaxy type with the evolutionary code PEGASE.3.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 22:30:25 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Seymour",
"Nick",
""
],
[
"Rocca-Volmerange",
"Brigitte",
""
],
[
"de Lapparent",
"Valerie",
""
]
] |
0706.3069 | Fatihcan M. Atay | Fatihcan M. Atay, Turker Biyikoglu, Juergen Jost | Network synchronization: Spectral versus statistical properties | null | Physica D 224:35-41 (2006) | 10.1016/j.physd.2006.09.018 | null | cond-mat.dis-nn nlin.AO | null | We consider synchronization of weighted networks, possibly with asymmetrical
connections. We show that the synchronizability of the networks cannot be
directly inferred from their statistical properties. Small local changes in the
network structure can sensitively affect the eigenvalues relevant for
synchronization, while the gross statistical network properties remain
essentially unchanged. Consequently, commonly used statistical properties,
including the degree distribution, degree homogeneity, average degree, average
distance, degree correlation, and clustering coefficient, can fail to
characterize the synchronizability of networks.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 22:15:24 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Atay",
"Fatihcan M.",
""
],
[
"Biyikoglu",
"Turker",
""
],
[
"Jost",
"Juergen",
""
]
] |
0706.3070 | Boris Altshuler | Boris L. Altshuler | Potential for the slow-roll inflation, mass scale hierarchy and Dark
Energy from the Type IIA supergravity | 32 pages, Latex | JCAP0709:012,2007 | 10.1088/1475-7516/2007/09/012 | null | hep-th | null | The magnetic fluxbrane solution with a strongly warped throat is studied in
the Type IIA supergravity theory with co-dimension one local source which
surves as $Z_{2}$-symmetric UV boundary of the throat. Overall volume of extra
space is stabilized since introduction of the local source breaks the no-scale
structure of the theory and evades the no-go theorem. Radion field is defined
as the position of UV boundary "moved" from its stable value fixed by the
anisotropic Israel junction conditions. Analytical expression for the radion
effective potential is received. Potential decreases exponentially (exponent is
equal to 0,21 in Planck units) in the slow-roll region and apparently meets
other demands of the early inflation. Reissner-Nordstrom type deformation of
the elementary fluxbrane solution permits to construct the IR end of the throat
and results in tiny positive non-zero value of the radion potential in its
extremal point seen today as Dark Energy $\rho_{D.E.}$. Expressions for the
mass scale hierarchy and for the "acceleration hierarchy" received in the paper
give the physically interesting relation between two hierarchies: $\rho_{D.E.}
\sim G_{N}^{2}m^{8}$.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 23:06:40 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Altshuler",
"Boris L.",
""
]
] |
0706.3071 | Jorge Milhazes Freitas | Ana Cristina Moreira Freitas, Jorge Milhazes Freitas | Extreme values for Benedicks-Carleson quadratic maps | 18 pages | Ergodic Theory Dynam. Systems 28, 2008, no. 4, 1117-1133 | null | null | math.DS math.PR math.ST stat.TH | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider the quadratic family of maps given by $f_{a}(x)=1-a x^2$ with
$x\in [-1,1]$, where $a$ is a Benedicks-Carleson parameter. For each of these
chaotic dynamical systems we study the extreme value distribution of the
stationary stochastic processes $X_0,X_1,...$, given by $X_{n}=f_a^n$, for
every integer $n\geq0$, where each random variable $X_n$ is distributed
according to the unique absolutely continuous, invariant probability of $f_a$.
Using techniques developed by Benedicks and Carleson, we show that the limiting
distribution of $M_n=\max\{X_0,...,X_{n-1}\}$ is the same as that which would
apply if the sequence $X_0,X_1,...$ was independent and identically
distributed. This result allows us to conclude that the asymptotic distribution
of $M_n$ is of Type III (Weibull).
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 23:29:48 GMT"
},
{
"version": "v2",
"created": "Wed, 16 Jun 2010 17:44:19 GMT"
}
] | 2010-06-17T00:00:00 | [
[
"Freitas",
"Ana Cristina Moreira",
""
],
[
"Freitas",
"Jorge Milhazes",
""
]
] |
0706.3072 | Samansa Maenshi | Samansa Maneshi, Jalani F. Kanem, Chao Zhuang, Matt Partlow, and
Aephraim M. Steinberg | Efficient vibrational state coupling in an optical tilted-washboard
potential via multiple spatial translations and application to pulse echo | 13 pages, 18 figures | Phys. Rev. A 77, 022303 (2008) | 10.1103/PhysRevA.77.022303 | null | quant-ph | null | We measure the application of simple and compound pulses consisting of
time-dependent spatial translations to coupling vibrational states of ultracold
85Rb atoms in a far-detuned 1D optical lattice. The lattice wells are so
shallow as to support only two bound states, and we prepare the atoms in the
ground state. The lattice is oriented vertically, leading to a tilted-washboard
potential analogous to those encountered in condensed-matter systems.
Experimentally, we find that a square pulse consisting of lattice displacements
and a delay is more efficient than single-step and Gaussian pulses. This is
described as an example of coherent control. It is striking that contrary to
the intuition that soft pulses minimize loss, the Gaussian pulse is
outperformed by the square pulse. Numerical calculations are in strong
agreement with our experimental results and show the superiority of the square
pulse to the single-step pulse for all lattice depths and to the Gaussian pulse
for lattice depths greater than 7 lattice recoil energies. We also compare the
effectiveness of these pulses for reviving oscillations of atoms in vibrational
superposition states using the pulse-echo technique. We find that the square
and Gaussian pulses result in higher echo amplitudes than the single-step
pulse. These improved echo pulses allow us to probe coherence at longer times
than in the past, measuring a plateau which has yet to be explained. In
addition, we show numerically that the vibrational state coupling due to such
lattice manipulations is more efficient in shallow lattices than in deep
lattices.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 19:36:54 GMT"
},
{
"version": "v2",
"created": "Tue, 4 Dec 2007 21:59:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Maneshi",
"Samansa",
""
],
[
"Kanem",
"Jalani F.",
""
],
[
"Zhuang",
"Chao",
""
],
[
"Partlow",
"Matt",
""
],
[
"Steinberg",
"Aephraim M.",
""
]
] |
0706.3073 | Alexei Borodin | D. Arinkin and A. Borodin | Tau-function of discrete isomonodromy transformations and probability | 26 pages | Compositio Math. 145 (2009) 747-772 | 10.1112/S0010437X08003862 | null | math.AG math-ph math.MP math.PR | null | We introduce the tau-function of a rational d-connection and its isomonodromy
transformations. We show that in a continuous limit our tau-function agrees
with the Jimbo-Miwa-Ueno tau-function, compute the tau-function for the
isomonodromy transformations leading to difference Painleve V and difference
Painleve VI equations, and prove that the gap probability for a wide class of
discrete random matrix type models can be viewed as the tau-function for an
associated d-connection.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 01:23:13 GMT"
}
] | 2014-01-14T00:00:00 | [
[
"Arinkin",
"D.",
""
],
[
"Borodin",
"A.",
""
]
] |
0706.3074 | Andrew Sullivan | A.L. Sullivan | A review of wildland fire spread modelling, 1990-present, 1: Physical
and quasi-physical models | 31 pages + 8 pages references + 2 figures + 5 tables. Submitted to
International Journal of Wildland Fire | Sullivan, A. L. 2009. Wildland surface fire spread modelling,
1990-2007. 1: Physical and quasi-physical models. International Journal of
Wildland Fire 18, 349-368 | 10.1071/WF06143 | null | physics.geo-ph physics.ao-ph physics.flu-dyn | null | In recent years, advances in computational power and spatial data analysis
(GIS, remote sensing, etc) have led to an increase in attempts to model the
spread and behaviour of wildland fires across the landscape. This series of
review papers endeavours to critically and comprehensively review all types of
surface fire spread models developed since 1990. This paper reviews models of a
physical or quasi-physical nature. These models are based on the fundamental
chemistry and/or physics of combustion and fire spread. Other papers in the
series review models of an empirical or quasi-empirical nature, and
mathematical analogues and simulation models. Many models are extensions or
refinements of models developed before 1990. Where this is the case, these
models are also discussed but much less comprehensively.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 02:12:42 GMT"
}
] | 2010-07-28T00:00:00 | [
[
"Sullivan",
"A. L.",
""
]
] |
0706.3075 | Jen-Tsung Hsiang | Jen-Tsung Hsiang, Tai-Hung Wu, Da-Shin Lee | Stochastic Lorentz forces on a point charge moving near the conducting
plate | 33 pages, 2 figures | Phys.Rev.D77:105021,2008 | 10.1103/PhysRevD.77.105021 | null | hep-th quant-ph | null | The influence of quantized electromagnetic fields on a nonrelativistic
charged particle moving near a conducting plate is studied. We give a
field-theoretic derivation of the nonlinear, non-Markovian Langevin equation of
the particle by the method of Feynman-Vernon influence functional. This
stochastic approach incorporates not only the stochastic noise manifested from
electromagnetic vacuum fluctuations, but also dissipation backreaction on a
charge in the form of the retarded Lorentz forces. Since the imposition of the
boundary is expected to anisotropically modify the effects of the fields on the
evolution of the particle, we consider the motion of a charge undergoing
small-amplitude oscillations in the direction either parallel or normal to the
plane boundary. Under the dipole approximation for nonrelativistic motion,
velocity fluctuations of the charge are found to grow linearly with time in the
early stage of the evolution at the rather different rate, revealing strong
anisotropic behavior. They are then asymptotically saturated as a result of the
fluctuation-dissipation relation, and the same saturated value is found for the
motion in both directions. The observational consequences are discussed. plane
boundary. Velocity fluctuations of the charge are found to grow linearly with
time in the early stage of the evolution at the rate given by the relaxation
constant, which turns out to be smaller in the parallel case than in the
perpendicular one in a similar configuration. Then, they are asymptotically
saturated as a result of the fluctuation-dissipation relation. For the
electron, the same saturated value is obtained for motion in both directions,
and is mainly determined by its oscillatory motion. Possible observational
consequences are discussed.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 02:16:42 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 02:03:22 GMT"
},
{
"version": "v3",
"created": "Mon, 21 Apr 2008 06:32:20 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hsiang",
"Jen-Tsung",
""
],
[
"Wu",
"Tai-Hung",
""
],
[
"Lee",
"Da-Shin",
""
]
] |
0706.3076 | Shiguo Lian | Shiguo Lian, Zhongxuan Liu, Zhen Ren, Haila Wang | On the Performance of Joint Fingerprint Embedding and Decryption Scheme | 10 pages,9 figures. To be submitted | null | null | null | cs.MM cs.CR | null | Till now, few work has been done to analyze the performances of joint
fingerprint embedding and decryption schemes. In this paper, the security of
the joint fingerprint embedding and decryption scheme proposed by Kundur et al.
is analyzed and improved. The analyses include the security against
unauthorized customer, the security against authorized customer, the
relationship between security and robustness, the relationship between
secu-rity and imperceptibility and the perceptual security. Based these
analyses, some means are proposed to strengthen the system, such as multi-key
encryp-tion and DC coefficient encryption. The method can be used to analyze
other JFD schemes. It is expected to provide valuable information to design JFD
schemes.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 02:44:44 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Lian",
"Shiguo",
""
],
[
"Liu",
"Zhongxuan",
""
],
[
"Ren",
"Zhen",
""
],
[
"Wang",
"Haila",
""
]
] |
0706.3077 | Sergey Sergeev | Vladimir V. Bazhanov, Vladimir V. Mangazeev, Sergey M. Sergeev | Exact solution of the Faddeev-Volkov model | 4 pages | Phys.Lett.A372:1547-1550,2008 | 10.1016/j.physleta.2007.10.053 | null | cond-mat.stat-mech hep-th math-ph math.MP | null | The Faddeev-Volkov model is an Ising-type lattice model with positive
Boltzmann weights where the spin variables take continuous values on the real
line. It serves as a lattice analog of the sinh-Gordon and Liouville models and
intimately connected with the modular double of the quantum group U_q(sl_2).
The free energy of the model is exactly calculated in the thermodynamic limit.
In the quasi-classical limit c->infinity the model describes quantum
fluctuations of discrete conformal transformations connected with the
Thurston's discrete analogue of the Riemann mappings theorem. In the
strongly-coupled limit c->1 the model turns into a discrete version of the D=2
Zamolodchikov's ``fishing-net'' model.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 03:26:45 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 03:21:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bazhanov",
"Vladimir V.",
""
],
[
"Mangazeev",
"Vladimir V.",
""
],
[
"Sergeev",
"Sergey M.",
""
]
] |
0706.3078 | Hajime Aoki | Hajime Aoki | Index Theorem in Finite Noncommutative Geometry | Latex 4 pages, uses ptptex.cls, Based on talk given at 21st
Nishinomiya-Yukawa Memorial Symposium on Theoretical Physics: Noncommutative
Geometry and Quantum Spacetime in Physics, Japan, 11-15 Nov 2006 | Prog.Theor.Phys.Suppl. 171 (2007) 228 | 10.1143/PTPS.171.228 | SAGA-HE-235 | hep-th hep-lat | null | Index theorem is formulated in noncommutative geometry with finite degrees of
freedom by using Ginsparg-Wilson relation. It is extended to the case where the
gauge symmetry is spontaneously broken. Dynamical analysis about topological
aspects in gauge theory is also shown.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 06:08:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Aoki",
"Hajime",
""
]
] |
0706.3079 | Shao-Ming Wang | Wang Shao-Ming, Han Liang, Ma Wen-Gan, Zhang Ren-You, and Jiang Yi | Revisiting the QCD corrections to the R-parity violating processes
$p\bar{p}/pp \to e\mu+X$ | 9 pages, 8 figures | Chin.Phys.Lett.25:58,2008 | 10.1088/0256-307X/25/1/017 | null | hep-ph | null | We present the theoretical predictions up to QCD NLO for the cross section of
high-mass electron-muon pair production at the Tevatron and the LHC,
considering only the dominant contributions from the third-generation
sneutrino. The dependence of the renormalization and factorization scales on
the total cross section, and the effects on the K-factor due to the uncertainty
of parton distribution function(PDF) have been carefully investigated. By
considering soft-gluon resummation effects to all order in $\alpha_s$ of
leading logarithm, we present the transverse momentum distributions of the
final $e\mu$ pair.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 03:45:46 GMT"
},
{
"version": "v2",
"created": "Tue, 13 Nov 2007 09:14:33 GMT"
},
{
"version": "v3",
"created": "Tue, 20 Nov 2007 07:15:41 GMT"
}
] | 2011-08-31T00:00:00 | [
[
"Shao-Ming",
"Wang",
""
],
[
"Liang",
"Han",
""
],
[
"Wen-Gan",
"Ma",
""
],
[
"Ren-You",
"Zhang",
""
],
[
"Yi",
"Jiang",
""
]
] |
0706.3080 | Kohkichi Konno | Kohkichi Konno, Toyoki Matsuyama, Satoshi Tanda | Does a black hole rotate in Chern-Simons modified gravity? | 4 pages, Accepted for publication in Phys. Rev. D | Phys.Rev.D76:024009,2007 | 10.1103/PhysRevD.76.024009 | null | gr-qc | null | Rotating black hole solutions in the (3+1)-dimensional Chern-Simons modified
gravity theory are discussed by taking account of perturbation around the
Schwarzschild solution. The zenith-angle dependence of a metric function
related to the frame-dragging effect is determined from a constraint equation
independently of a choice of the embedding coordinate. We find that at least
within the framework of the first-order perturbation method, the black hole
cannot rotate for finite black hole mass if the embedding coordinate is taken
to be a timelike vector. However, the rotation can be permitted in the limit of
$M/r \to 0$ (where $M$ is the black hole mass and $r$ is the radius). For a
spacelike vector, the rotation can also be permitted for any value of the black
hole mass.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 04:04:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Konno",
"Kohkichi",
""
],
[
"Matsuyama",
"Toyoki",
""
],
[
"Tanda",
"Satoshi",
""
]
] |
0706.3081 | Xi-Ping Zhu | Bing-Long Chen | Strong Uniqueness of the Ricci Flow | 21 pages | Journal of Differential Geometry 82 (2009) 363-382 | null | null | math.DG math.AP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this paper, we derive some local a priori estimates for Ricci flow. This
gives rise to some strong uniqueness theorems. As a corollary, let $g(t)$ be a
smooth complete solution to the Ricci flow on $\mathbb{R}^{3}$, with the
canonical Euclidean metric $E$ as initial data, then $g(t)$ is trivial, i.e.
$g(t)\equiv E$.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 04:11:10 GMT"
},
{
"version": "v2",
"created": "Tue, 5 Oct 2010 05:24:18 GMT"
}
] | 2010-10-06T00:00:00 | [
[
"Chen",
"Bing-Long",
""
]
] |
0706.3082 | Scott Kominers | Scott D. Kominers | Configurations of Extremal Even Unimodular Lattices | 8 pages. To appear, International Journal of Number Theory | International Journal of Number Theory 5(3), (2009), 457-464 | 10.1142/S179304210900216X | null | math.NT | null | We extend the results of Ozeki on the configurations of extremal even
unimodular lattices. Specifically, we show that if L is such a lattice of rank
56, 72, or 96, then L is generated by its minimal-norm vectors.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 04:41:43 GMT"
},
{
"version": "v2",
"created": "Mon, 10 Dec 2007 17:23:54 GMT"
}
] | 2011-11-11T00:00:00 | [
[
"Kominers",
"Scott D.",
""
]
] |
0706.3083 | Hiroshi Suzuki | Hiroshi Suzuki | Perturbative spectrum of a Yukawa-Higgs model with Ginsparg-Wilson
fermions | 10 pages | null | null | RIKEN-TH-107 | hep-lat hep-th | null | A Yukawa-Higgs model with Ginsparg-Wilson (GW) fermions, proposed recently by
Bhattacharya, Martin and Poppitz as a possible lattice formulation of chiral
gauge theories, is studied. A simple argument shows that the gauge boson always
acquires mass by the St\"uckelberg (or, in a broad sense, Higgs) mechanism,
regardless of strength of interactions. The gauge symmetry is spontaneously
broken. When the gauge coupling constant is small, the physical spectrum of the
model consists of massless fermions, massive fermions and \emph{massive} vector
bosons.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 04:46:25 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 02:00:14 GMT"
}
] | 2007-06-28T00:00:00 | [
[
"Suzuki",
"Hiroshi",
""
]
] |
0706.3084 | Carlos A. Rodriguez-Rico | C. A. Rodriguez-Rico (1), W. M. Goss (2), J. L. Turner (3), Y. Gomez
(4) ((1) Departamento de Astronomia, Universidad de Guanajuato, (2) NRAO, (3)
Department of Physics and Astronomy, UCLA, (4) CRyA, UNAM) | VLA H53alpha observations of the central region of the Super Star
Cluster Galaxy NGC 5253 | Accepted in Astrophysical Journal 7 figures | null | 10.1086/520709 | null | astro-ph | null | We present observations in the H53alpha line and radio continuum at 43 GHz
carried out with the VLA in the D array (2'' angular resolution) toward the
starburst galaxy NGC 5253. VLA archival data have been reprocessed to produce a
uniform set of 2, 1.3 and 0.7 cm high angular (0.''2 X 0.''1) radio continuum
images. The RRL H53alpha, a previously reported measurement of the H92alpha RRL
flux density and the reprocessed high angular resolution radio continuum flux
densities have been modeled using a collection of HII regions. Based on the
models, the ionized gas in the nuclear source has an electron density of ~6 X
10^4 cm^-3 and an volume filling factor of 0.05. A Lyman continuum photon
production rate of 2 X 10^52 s^-1 is necessary to sustain the ionization in the
nuclear region. The number of required O7 stars in the central 1.5 pc of the
supernebula is ~ 2000. The H53alpha velocity gradient 10 km s^-1 arcsec^-1)
implies a dynamical mass of ~3X10^5 Msun; this mass suggests the supernebula is
confined by gravity.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 05:05:54 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rodriguez-Rico",
"C. A.",
""
],
[
"Goss",
"W. M.",
""
],
[
"Turner",
"J. L.",
""
],
[
"Gomez",
"Y.",
""
]
] |
0706.3085 | Valentina Klochkova | Tonu Kipper (1) and Valentina Klochkova (2) ((1) - Tartu Observatory,
Toravere, Estonia; (2) - Special Astrophysical Observatory RAS, Nizhnij
Arkhyz, Russia) | The optical spectrum of R Coronae Borealis close to 2003 decline | 14 pages, 8 figures, baltlat2.sty | BalticAstron.15:521-530,2007 | null | null | astro-ph | null | Two sets of high-resolution spectra of R CrB obtained during the 2003 light
decline are described. The first set was obtained on the descending branch of
the light curve when V ~12.0 and the second one in the recovery phase with V
~7.5. The usual sharp and broad emissions are described and the lines radial
velocities measured. C_2 Swan system (0,0) band was found to be in emission for
the first set. The other C_2 bands were in absorption. Few CN red system (5,1)
band rotational lines and low excitation FeI lines were in absorption. A table
with measured radial velocities of various spectral features is presented.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 05:39:46 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kipper",
"Tonu",
""
],
[
"Klochkova",
"Valentina",
""
]
] |
0706.3086 | Kei Funano | Kei Funano | Estimates of Gromov's box distance | 11pages | null | null | null | math.MG | null | In 1999, M. Gromov introduced the box distance function $\sikaku$ on the
space of all mm-spaces. In this paper, by using the method of T. H. Colding
(cf. \cite[Lemma 5.10]{Colding}), we estimate
$\sikaku(\mathbb{S}^n,\mathbb{S}^m)$ and $\sikaku (\mathbb{C}P^n,
\mathbb{C}P^m)$, where $\mathbb{S}^n$ is the $n$-dimensional unit sphere in
$\mathbb{R}^{n+1}$ and $\mathbb{C}P^n$ is the $n$-dimensional complex
projective space equipped with the Fubini-Study metric. In paticular, we give
the complete answer to an Exercise of Gromov's Green book (cf. \cite[Section
$3{1/2}.18$]{gromov}). We also estimate $\sikaku \big(SO(n), SO(m)\big)$ from
below, where SO(n) is the special orthogonal group.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 05:49:29 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Funano",
"Kei",
""
]
] |
0706.3087 | Kazim Buyukboduk | Kazim Buyukboduk | Stark units and main conjectures for totally real fields | 33 pages | Compositio Math. 145 (2009) 1163-1195 | 10.1112/S0010437X09004163 | null | math.NT | null | Main theorem of [Buyukboduk, arXiv:0706.0377v1] suggests that it should be
possible to lift the Kolyvagin systems of Stark units constructed in
[Buyukboduk, arXiv:math/0703426v1] to a Kolyvagin system over the cyclotomic
Iwasawa algebra. This is what we prove in this paper. This construction gives
the first example towards a more systematic study of Kolyvagin system theory
over an Iwasawa algebra when the core Selmer rank is greater than one. As a
result of this construction, we reduce the main conjectures of Iwasawa theory
for totally real fields to a statement of local Iwasawa theory. This statement,
however, turns out to be interesting in its own right as it suggests a relation
between solutions to $p$-adic and complex Stark conjectures.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 06:04:10 GMT"
}
] | 2019-02-20T00:00:00 | [
[
"Buyukboduk",
"Kazim",
""
]
] |
0706.3088 | Avinash Singh | Sudhakar Pandey and Avinash Singh | Quantum and thermal fluctuations in a two-dimensional correlated band
ferromagnet -- Goldstone-mode preserving investigation with self-energy and
vertex corrections | 9 pages, 7 figures | Phys. Rev. B 76, 104437 (2007) | 10.1103/PhysRevB.76.104437 | null | cond-mat.str-el | null | Ferromagnetism in the t-t' Hubbard model is investigated on a square lattice.
Correlation effects in the form of self-energy and vertex corrections are
systematically incorporated within a spin-rotationally-symmetric scheme which
explicitly preserves the Goldstone mode and is therefore in accord with the
Mermin-Wagner theorem. Interplay of band dispersion and correlation effects on
ferromagnetic-state stability are highlighted with respect to both long- and
short-wavelength fluctuations, which are shown to have substantially different
behaviour. Our approach provides a novel understanding of the enhancement of
ferromagnetism near van Hove filling for t'~0.5 in terms of strongly suppressed
saddle-point contribution to the destabilizing exchange part of spin stiffness.
Finite-temperature electron spin dynamics is investigated directly in terms of
spectral-weight transfer across the Fermi energy due to electron-magnon
coupling. Relevant in the context of recent magnetization measurements on
ultrathin films, the role of strong thermal spin fluctuations in low dimensions
is highlighted, in the anisotropy-stabilized ordered state, by determining the
thermal decay of magnetization and T_c within a renormalized spin-fluctuation
theory.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 06:19:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pandey",
"Sudhakar",
""
],
[
"Singh",
"Avinash",
""
]
] |
0706.3089 | Ryan Hickox | Ryan C. Hickox and Maxim Markevitch (Harvard-Smithsonian Center for
Astrophysics) | Can Chandra resolve the remaining cosmic X-ray background? | 9 emulateapj pages, 8 figures, v3: matches version to appear in ApJ
(note correction to approximation of Poisson errors) | Astrophys.J. 671 (2007) 1523-1531 | 10.1086/522918 | null | astro-ph | null | The deepest extragalactic X-ray observation, the 2 Ms Chandra Deep Field
North (CDF-N), resolves ~80% of the total extragalactic cosmic X-ray background
(CXB) in the 1-2 keV band. Recent work has shown that 70% of the remaining CXB
flux is associated with sources detected by the Hubble Space Telescope (HST).
This paper uses the existing CDF-N data to constrain the X-ray flux
distribution of these X-ray undetected HST sources, by comparing the number of
0.5-2 keV X-ray counts at the HST positions to those expected for model flux
distributions. In the simple case where all the undetected HST X-ray sources
have the same 0.5-2 keV flux, the data are best fit by 1.5-3 counts per source
in 2 Ms, compared to a detection limit (at 10% completeness) of 9 counts.
Assuming a more realistic power-law logN-logS distribution [N(>S) S^-alpha],
the data favor a relatively steep flux distribution, with alpha=1.1^+0.5_-0.3
(limits are 99% confidence). This slope is very similar to that previously
found for faint normal and starburst galaxies in the CDF-N. These results
suggest deeper Chandra observations will detect a new population of faint X-ray
sources, but extremely deep exposures are needed to resolve the remainder of
the soft CXB. In the most optimistic scenario, when the HST sources have the
flattest allowed flux distribution and all the sources without HST counterparts
are detected, observations 5 times more sensitive than the existing ones would
resolve at most ~60% of the remaining soft CXB.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 19:37:49 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 20:10:04 GMT"
},
{
"version": "v3",
"created": "Tue, 27 Nov 2007 17:58:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hickox",
"Ryan C.",
"",
"Harvard-Smithsonian Center for\n Astrophysics"
],
[
"Markevitch",
"Maxim",
"",
"Harvard-Smithsonian Center for\n Astrophysics"
]
] |
0706.3090 | Sergei Mukhin I | I.N. Krivonos and S.I. Mukhin | Flexible-to-semiflexible chain crossover on the pressure-area isotherm
of lipid bilayer | 31 pages; 7 figures; submitted to JETP | null | 10.1007/s11447-008-1011-6 | null | q-bio.QM q-bio.BM | null | We found theoretically that competition between ~Kq^4 and ~Qq^2 terms in the
Fourier transformed conformational energy of a single lipid chain, in
combination with inter-chain entropic repulsion in the hydrophobic part of the
lipid (bi)layer, may cause a crossover on the bilayer pressure-area isotherm
P(A)~(A-A_0)^{-n}. The crossover manifests itself in the transition from n=5/3
to n=3. Our microscopic model represents a single lipid molecule as a worm-like
chain with finite irreducible cross-section area A_0, flexural rigidity K and
stretching modulus Q in a parabolic potential with self-consistent curvature
B(A) formed by entropic interactions between hydrocarbon chains in the lipid
layer. The crossover area per lipid A* obeys relation Q^2/(KB(A*))~1 . We
predict a peculiar possibility to deduce effective elastic moduli K and Q of
the individual hydrocarbon chain from the analysis of the isotherm possessing
such crossover. Also calculated is crossover-related behavior of the area
compressibility modulus K_a, equilibrium area per lipid A_t, and chain order
parameter S.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 06:43:32 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Krivonos",
"I. N.",
""
],
[
"Mukhin",
"S. I.",
""
]
] |
0706.3091 | Ruying Xue | Ruying Xue | On the well-posedness of the Cauchy problem for the generalized
Korteweg-de Vries-Burgers equation | 20 pages | null | null | null | math.AP | null | Considered is the generalized Korteweg-de Vries-Burgers equation $$
u_{t}+u_{xxx}+uu_{x}+|D_{x}|^{2\alpha}u=0,\quad t\in \mathbb{R}^{+}, x\in
\mathbb{R}, $$ with $0\leq \alpha\le 1$. We prove a sharp results on the
associated Cauchy problem in the Sobolev space $ {H}^s(\mathbb{R})$. For
$s>-\min\{\frac {3+2\alpha}4, 1\}$ we give the well-posedness of solutions of
the Cauchy problem, while for $\frac 12\le\alpha\le 1$ and for $s<-\min\{\frac
{3+2\alpha}4, 1\}$ we show some ill-posedness issues.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 07:18:32 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Xue",
"Ruying",
""
]
] |
0706.3092 | M.-L. Labbi | Labbi M.-L | On $(2k)$-Minimal Submanifolds | 18 pages | null | null | null | math.DG | null | Recall that a submanifold of a Riemannian manifold is said to be minimal if
its mean curvature is zero. It is classical that minimal submanifolds are the
critical points of the volume function. In this paper, we examine the critical
points of the total $(2k)$-th Gauss-Bonnet curvature function, called
$(2k)$-minimal submanifolds. We prove that they are characterized by the
vanishing of a higher mean curvature, namely the $(2k+1)$-Gauss-Bonnet
curvature. Furthermore, we show that several properties of usual minimal
submanifolds can be naturally generalized to $(2k)$-minimal submanifolds.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 07:39:18 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"-L",
"Labbi M.",
""
]
] |
0706.3093 | Sergei Stishov | S. M. Stishov, A.E. Petrova, S. Khasanov, G. Kh. Panova, A.A.Shikov,
J. C. Lashley, D. Wu, and T. A. Lograsso | Addendum: "On the nature of the phase transition in the itinerant
helimagnet MnSi", arXiv:cond-mat/0702460v1 [cond-mat.str-el] | null | null | null | null | cond-mat.str-el | null | New high resolution data for heat capacity, heat capacity under applied
magnetic fields and resistivity of high quality single crystal of MnSi are
reported. Striking mirror symmetry between temperature derivative of
resistivity and thermal expansion coefficient of MnSi is displayed. Close
similarity between variation of the heat capacity and the temperature
derivative of resistivity through the phase transition is observed. It is shown
that the heat capacity and thermal expansion coefficient of the helical phase
are not influenced by moderate magnetic field.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 13:19:19 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Stishov",
"S. M.",
""
],
[
"Petrova",
"A. E.",
""
],
[
"Khasanov",
"S.",
""
],
[
"Panova",
"G. Kh.",
""
],
[
"Shikov",
"A. A.",
""
],
[
"Lashley",
"J. C.",
""
],
[
"Wu",
"D.",
""
],
[
"Lograsso",
"T. A.",
""
]
] |
0706.3094 | X. L. Lei | X. L. Lei | Direct-current control of radiation-induced differential
magnetoresistance oscillations in two-dimensional electron systems | 4 pages, 2 figues, published version | Applied Physics Letters 91, 112104 (2007) | 10.1063/1.2783260 | null | cond-mat.mes-hall | null | Magnetoresistance oscillations in two-dimensional electron systems driven
simultaneously by a strong direct current and a microwave irradiation, are
analyzed within a unified microscopic scheme treating both excitations on an
equal footing. The microwave-induced resistance oscillations are described by a
parameter $\epsilon_\omega$ proportional to the radiation frequency, while the
dc-induced resistance oscillations are governed by a parameter $\epsilon_j$
proportional to the current density. In the presence of both a microwave
radiation and a strong dc, the combined parameter $\epsilon_\omega+\epsilon_j$
is shown to control the main resistance oscillations, in agreement with the
recent measurement [Zhang {\it et al.} Phys. Rev. Lett. {\bf 98}, 106804
(2007)]
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 07:54:39 GMT"
},
{
"version": "v2",
"created": "Wed, 19 Sep 2007 03:48:16 GMT"
}
] | 2007-09-19T00:00:00 | [
[
"Lei",
"X. L.",
""
]
] |
0706.3095 | Edward M. Drobyshevski | E. M. Drobyshevski | Channeling Effect and Improvement of the Efficiency of Charged Particle
Registration with Crystal Scintillators | 10 pages | Mod.Phys.Lett.A23:3077-3085,2008 | 10.1142/S0217732308028430 | null | physics.ins-det hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The importance is emphasized of taking into account the channeling along the
low index crystallographic axes and planes of a part of low-energy (1-10 keV)
recoil ions in measurements of their parameters with crystal scintillators of
the type of NaI(Tl) etc. Because the nucleus stopping power in channels is low
as compared with electronic stopping power, the light yield of the scintillator
must be, accordingly, higher in the given case than that for ions having higher
energy (tens keV and more), which lose most part of their energy via nuclear
collisions outside channels. Hence, in particular, it follows that the DAMA/NaI
observations in Gran Sasso of the annual modulation of the signal frequency in
a narrow range of scintillations with an amplitude of 2-6 keV electron
equivalent may be due to incidence onto the Earth of exceedingly massive
particles (of the type of Planckian objects) from elongated Earth-crossing
heliocentric orbits at a velocity of 30-50 km/s. In NaI(Tl), these particles
create the iodine recoil ions with just the energy of 2-6 keV.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 13:38:24 GMT"
},
{
"version": "v2",
"created": "Tue, 15 Jul 2008 09:01:27 GMT"
}
] | 2008-12-25T00:00:00 | [
[
"Drobyshevski",
"E. M.",
""
]
] |
0706.3096 | Wuming Yang | W. M. Yang and S. L. Bi | The frequency separations of stellar p-modes | Accepted for Publication in A&A, 8 pages, 5 figures | A&A 472, 571-576 (2007) | 10.1051/0004-6361:20077082 | null | gr-qc | null | Aims. The purpose of this work is to investigate a new frequency separation
of stellar p-modes and its characteristics. Methods. Frequency separations are
deduced from the asymptotic formula of stellar p-modes. Then, using the
theoretical adiabatic frequencies of stellar model, we compute the frequency
separations. Results. A new separation $\sigma_{l-1 l+1}(n)$, which is similar
to the scaled small separation $d_{l l+2}(n)/(2l+3)$, is obtained from the
asymptotic formula of stellar p-modes. The separations $\sigma_{l-1 l+1}(n)$
and $d_{l l+2}(n)/(2l+3)$ have the same order. And like the small separation,
$\sigma_{l-1 l+1}(n)$ is mainly sensitive to the conditions in the stellar
core. However, with the decrease of the central hydrogen abundance of stars,
the $\sigma_{02}$ and $\sigma_{13}$ more and more deviate from the scaled small
separation. This characteristic could be used to extract the information on the
central hydrogen abundance of stars.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:06:18 GMT"
},
{
"version": "v2",
"created": "Mon, 3 Sep 2007 16:13:38 GMT"
}
] | 2007-09-03T00:00:00 | [
[
"Yang",
"W. M.",
""
],
[
"Bi",
"S. L.",
""
]
] |
0706.3097 | Stefan Czesla | S. Czesla, J.H.H.M. Schmitt | The nature of the fluorescent iron line in V 1486 Ori | 4 pages, letter, accepted for publication in A&A | null | 10.1051/0004-6361:20077741 | null | astro-ph | null | The fluorescent 6.4 keV iron line provides information on cool material in
the vicinity of hard X-ray sources as well as on the characteristics of the
X-ray sources themselves. First discovered in the X-ray spectra of the flaring
Sun, X-ray binaries and active galactic nuclei (AGN), the fluorescent line was
also observed in a number of stellar X-ray sources. The young stellar object
(YSO) V1486 Ori was observed in the framework of the Chandra Ultra Deep Project
(COUP) as the source COUP 331. We investigate its spectrum, with emphasis on
the strength and time variability of the fluorescent iron K-alpha line, derive
and analyze the light curve of COUP 331 and proceed with a time-resolved
spectral analysis of the observation. The light curve of V 1486 Ori shows two
major flares, the first one lasting for (approx) 20 ks with a peak X-ray
luminosity of 2.6*10^{32} erg/s (dereddened in the 1-10 keV band) and the
second one -- only partially observed -- for >60 ks with an average X-ray
luminosity of 2.4*10^{31} erg/s (dereddened). The spectrum of the first flare
is very well described by an absorbed thermal model at high temperature, with a
pronounced 6.7 keV iron line complex, but without any fluorescent K-alpha line.
The X-ray spectrum of the second flare is characterized by even higher
temperatures (>= 10 keV) without any detectable 6.7 keV Fe XXV feature, but
with a very strong fluorescent iron K-alpha line appearing predominantly in the
20 ks rise phase of the flare. Preliminary model calculations indicate that
photoionization is unlikely to account for the entire fluorescent emission
during the rise phase.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:18:47 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Czesla",
"S.",
""
],
[
"Schmitt",
"J. H. H. M.",
""
]
] |
0706.3098 | Antonio C. C. Guimar\~aes | Antonio C. C. Guimar\~aes and Laerte Sodr\'e Jr. (IAG-USP) | Bayesian analysis of joint strong gravitational lensing and dynamic
galactic mass in SLACS: evidence of line-of-sight contamination | 11 pages, 3 figures, submitted to ApJ | null | null | null | astro-ph | null | We readdress the calculation of the mass of early-type galaxies using strong
gravitational lensing and stellar dynamics. Our sample comprises 27 galaxies in
the Sloan Lens ACS (SLACS) Survey. Comparing the mass estimates from these two
independent methods in a Bayesian framework, we find evidence of significant
line-of-sight mass contamination. Assuming a power-law mass distribution, the
best fit density profile is given by $\rho \propto r^{-1.69\pm0.05}$. We show
that neglecting the line-of-sight mass contamination produces an overestimate
of the mass attributed to the lens-galaxy by the lensing method, which
introduces a bias in favor of a SIS profile when using the joint lensing and
dynamic analysis to determine the slope of the density profile. We suggest that
the line-of-sight contamination could also be important for other astrophysical
and cosmological uses of joint lensing and dynamical measurements.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 13:40:45 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Guimarães",
"Antonio C. C.",
"",
"IAG-USP"
],
[
"Sodré",
"Laerte",
"Jr.",
"IAG-USP"
]
] |
0706.3099 | Adam Micolich | A.P. Micolich, L.L. Bell, and A.R. Hamilton | An Improved Process for Fabricating High-Mobility Organic Molecular
Crystal Field-Effect Transistors | 18 pages, 5 figures | null | 10.1063/1.2802284 | null | cond-mat.soft cond-mat.mtrl-sci | null | In this paper we present an improved process for producing elastomer
transistor stamps and high-mobility organic field-effect transistors (FETs)
based on semiconducting acene molecular crystals. In particular, we have
removed the need to use a silanized Si wafer for curing the stamps and to
handle a fragile micron-thickness polydimethylsiloxane (PDMS) insulating film
and laminate it, bubble free, against the PDMS transistor stamp. We find that
despite the altered design, rougher PDMS surface, and lamination and
measurement of the device in air, we still achieve electrical mobilities of
order 10 cm^2/Vs, comparable to the current state of the art in organic FETs.
Our device shows hole conduction with a threshold voltage of order -9V, which
corresponds to a trap density of 1.4 x 10^10 cm^-2.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:21:49 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Micolich",
"A. P.",
""
],
[
"Bell",
"L. L.",
""
],
[
"Hamilton",
"A. R.",
""
]
] |
0706.3100 | Xue Fei | Fei Xue, Y. D. Wang, Yu-xi Liu, Franco Nori | Cooling a Micromechanical Beam by Coupling it to a Transmission Line | 6 pages, 4 figures | PHYSICAL REVIEW B 76, 205302 (2007) | 10.1103/PhysRevB.76.205302 | null | cond-mat.mes-hall cond-mat.supr-con | null | We study a method to cool down the vibration mode of a micro-mechanical beam
using a capacitively-coupled superconducting transmission line. The Coulomb
force between the transmission line and the beam is determined by the driving
microwave on the transmission line and the displacement of the beam. When the
frequency of the driving microwave is smaller than that of the transmission
line resonator, the Coulomb force can oppose the velocity of the beam. Thus,
the beam can be cooled. This mechanism, which may enable to prepare the beam in
its quantum ground state of vibration, is feasible under current experimental
conditions.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:21:52 GMT"
},
{
"version": "v2",
"created": "Thu, 28 Jun 2007 12:05:43 GMT"
},
{
"version": "v3",
"created": "Fri, 2 Nov 2007 01:30:11 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Xue",
"Fei",
""
],
[
"Wang",
"Y. D.",
""
],
[
"Liu",
"Yu-xi",
""
],
[
"Nori",
"Franco",
""
]
] |
0706.3101 | Dietrich Stauffer | D. Stauffer | The Penna Model of Biological Aging | 16-page invited review submitted to Bioinformatics and Biology
Insights | null | null | null | q-bio.PE | null | This review deals with computer simulation of biological ageing, particularly
with the Penna model of 1995.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:22:44 GMT"
}
] | 2007-06-22T00:00:00 | [
[
"Stauffer",
"D.",
""
]
] |
0706.3102 | Domenico Ditto | A.Orefice, R.Giovanelli, D.Ditto | Complete Hamiltonian description of wave-like features in classical and
quantum physics | The scientific content is unchanged. Abstract, Introduction and
Conclusions were improved. The new version is given in 7 pages and double
column and includes 6 figures | null | null | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The analysis of the Helmholtz equation is shown to lead to an exact
Hamiltonian system of equations describing in terms of ray trajectories a very
wide family of wave-like phenomena (including diffraction and interference)
going much beyond the limits of the ordinary geometrical optics approximation,
which is contained as a simple limiting case. Due to the fact that the time
independent Schroedinger equation is itself a Helmoltz-like equation, the same
mathematical solutions holding for a classical optical beam turn out to apply
to a quantum particle beam, leading to a complete system of Hamiltonian
equations which provide a set of particle trajectories and motion laws
containing as a limiting case the ones encountered in classical Mechanics.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 13:43:05 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Nov 2007 15:08:38 GMT"
},
{
"version": "v3",
"created": "Thu, 13 Mar 2008 13:42:06 GMT"
},
{
"version": "v4",
"created": "Fri, 6 Jun 2008 13:02:13 GMT"
},
{
"version": "v5",
"created": "Tue, 16 Sep 2008 14:39:12 GMT"
}
] | 2008-09-16T00:00:00 | [
[
"Orefice",
"A.",
""
],
[
"Giovanelli",
"R.",
""
],
[
"Ditto",
"D.",
""
]
] |
0706.3103 | Michael Kuchiev | M. Yu. Kuchiev | Production of high energy particles in laser and Coulomb fields and
e^+e^- antenna | 4 pages | Phys.Rev.Lett.99:130404,2007 | 10.1103/PhysRevLett.99.130404 | null | physics.atom-ph | null | A strong laser field and the Coulomb field of a nucleus can produce
e^{+}e^{-} pairs. It is shown for the first time that there is a large
probability that electrons and positrons created in this process collide after
one or several oscillations of the laser field. These collisions can take place
at high energy resulting in several phenomena. The quasielastic collision
e^{+}e^{-} -> e^{+}e^{-} allows acceleration of leptons in the laser field to
higher energies. The inelastic collisions allow production of high energy
photons e^{+}e^{-}-> 2 gamma and muons, e^{+}e^{-} -> mu^{+}mu^{-}. The yield
of high-energy photons and muons produced via this mechanism exceeds
exponentially their production through conventional direct creation in laser
and Coulomb fields. A relation of the phenomena considered with the
antenna-mechanism of multiphoton absorption in atoms is discussed.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:45:26 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Kuchiev",
"M. Yu.",
""
]
] |
0706.3104 | Cristina Toninelli | Marc Mezard, Cristina Toninelli | Group Testing with Random Pools: optimal two-stage algorithms | 12 pages | null | null | null | cs.DS cond-mat.dis-nn cond-mat.stat-mech cs.IT math.IT | null | We study Probabilistic Group Testing of a set of N items each of which is
defective with probability p. We focus on the double limit of small defect
probability, p<<1, and large number of variables, N>>1, taking either p->0
after $N\to\infty$ or $p=1/N^{\beta}$ with $\beta\in(0,1/2)$. In both settings
the optimal number of tests which are required to identify with certainty the
defectives via a two-stage procedure, $\bar T(N,p)$, is known to scale as
$Np|\log p|$. Here we determine the sharp asymptotic value of $\bar
T(N,p)/(Np|\log p|)$ and construct a class of two-stage algorithms over which
this optimal value is attained. This is done by choosing a proper bipartite
regular graph (of tests and variable nodes) for the first stage of the
detection. Furthermore we prove that this optimal value is also attained on
average over a random bipartite graph where all variables have the same degree,
while the tests have Poisson-distributed degrees. Finally, we improve the
existing upper and lower bound for the optimal number of tests in the case
$p=1/N^{\beta}$ with $\beta\in[1/2,1)$.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:57:44 GMT"
}
] | 2007-11-14T00:00:00 | [
[
"Mezard",
"Marc",
""
],
[
"Toninelli",
"Cristina",
""
]
] |
0706.3105 | Giulia Zanderighi | Duncan Brown, Daniel Traynor, Alexander Savin and Giulia Zanderighi | Hadronic Final States | 15 pages, summary of the QCD and Hadronic Final State Working Group
of the 15th International Workshop on Deep-Inelastic Scattering and Related
Subjects (DIS2007), Munich, Germany, 16-20 Apr 2007 | null | null | CERN-PH-TH-07-095 | hep-ph | null | In this summary we give a concise overview of the experimental and
theoretical results, which were presented during the QCD and Hadronic Final
State Working Group sessions at the DIS 2007 workshop.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 08:55:52 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 15:38:46 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Brown",
"Duncan",
""
],
[
"Traynor",
"Daniel",
""
],
[
"Savin",
"Alexander",
""
],
[
"Zanderighi",
"Giulia",
""
]
] |
0706.3106 | Salia Cherifi | S. Cherifi, R. Hertel, A. Locatelli, Y. Watanabe, G. Potdevin, A.
Ballestrazzi, M. Balboni and S. Heun | Tuning the domain wall orientation in thin magnetic strips by induced
anisotropy | null | Appl. Phys. Lett. 91, 092502 (2007) | 10.1063/1.2778466 | null | cond-mat.other | null | We report on a method to tune the orientation of in-plane magnetic domains
and domain walls in thin ferromagnetic strips by manipulating the magnetic
anisotropy. Uniaxial in-plane anisotropy is induced in a controlled way by
oblique evaporation of magnetic thin strips. A direct correlation between the
magnetization direction and the domain wall orientation is found experimentally
and confirmed by micromagnetic simulations. The domain walls in the strips are
always oriented along the oblique evaporation-induced easy axis, in spite of
the shape anisotropy. The controlled manipulation of domain wall orientations
could open new possibilities for novel devices based on domain-wall
propagation.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:03:48 GMT"
}
] | 2007-09-17T00:00:00 | [
[
"Cherifi",
"S.",
""
],
[
"Hertel",
"R.",
""
],
[
"Locatelli",
"A.",
""
],
[
"Watanabe",
"Y.",
""
],
[
"Potdevin",
"G.",
""
],
[
"Ballestrazzi",
"A.",
""
],
[
"Balboni",
"M.",
""
],
[
"Heun",
"S.",
""
]
] |
0706.3107 | Julien Roth | Julien Roth (IECN) | Spinorial Characterization of Surfaces into 3-dimensional homogeneous
Manifolds | 35 pages | Journal of Geometry and Physics 60, 6-8 (2010) 1045-1061 | 10.1016/j.geomphys.2010.03.007 | null | math.DG | null | We give a spinorial characterization of isometrically immersed surfaces into
3-dimensional homogeneous manifolds with 4-dimensional isometry group in terms
of the existence of a particular spinor, called generalized Killing spinor.
This generalizes results by T. Friedrich for $\R^3$ and B. Morel for $\Ss^3$
and $\HH^3$. The main argument is the interpretation of the energy-momentum
tensor of a genralized Killing spinor as the second fondamental form up to a
tensor depending on the structure of the ambient space
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:04:57 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Roth",
"Julien",
"",
"IECN"
]
] |
0706.3108 | Adrian Alexandrescu | Adrian Alexandrescu, Alfonso Bueno-Orovio, Jose R. Salgueiro, Victor
M. Perez-Garcia | Mapped Chebyshev pseudospectral method to study multiple scale phenomena | siamltex documentclass; submitted for publication | null | null | null | physics.comp-ph physics.optics | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the framework of mapped pseudospectral methods, we introduce a new
polynomial-type mapping function in order to describe accurately the dynamics
of systems developing almost singular structures. Using error criteria related
to the spectral interpolation error, the new polynomial-type mapping is
compared against previously proposed mappings for the study of collapse and
shock wave phenomena. As a physical application, we study the dynamics of two
coupled beams, described by coupled nonlinear Schr\"odinger equations and
modeling beam propagation in an atomic coherent media, whose spatial sizes
differs up to several orders of magnitude. It is demonstrated, also by
numerical simulations, that the accuracy properties of the new polynomial-type
mapping outperforms in orders of magnitude the ones of the other studied
mapping functions.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:11:47 GMT"
},
{
"version": "v2",
"created": "Tue, 21 Oct 2008 08:07:41 GMT"
}
] | 2008-10-21T00:00:00 | [
[
"Alexandrescu",
"Adrian",
""
],
[
"Bueno-Orovio",
"Alfonso",
""
],
[
"Salgueiro",
"Jose R.",
""
],
[
"Perez-Garcia",
"Victor M.",
""
]
] |
0706.3109 | Shiro Sakai | Shiro Sakai, Ryotaro Arita, and Hideo Aoki | Itinerant ferromagnetism in the multiorbital Hubbard model: a dynamical
mean-field study | 4 pages, 5 figures | Phys. Rev. Lett. 99, 216402 (2007) | 10.1103/PhysRevLett.99.216402 | null | cond-mat.str-el | null | In order to resolve the long-standing issue of how the itinerant
ferromagnetism is affected by the lattice structure and Hund's coupling, we
have compared various three-dimensional lattice structures in the single- and
multiorbital Hubbard models with the dynamical mean-field theory with an
improved quantum Monte Carlo algorithm that preserves the spin-SU(2) symmetry.
The result indicates that {\it both} the lattice structure and the d-orbital
degeneracy are essential for the ferromagnetism in the parameter region
representing a transition metal. Specifically, (a) Hund's coupling, despite the
common belief, is important, which is here identified to come from
particle-hole scatterings, and (b) the ferromagnetism is a correlation effect
(outside the Stoner picture) as indicated from the band-filling dependence.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:33:00 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sakai",
"Shiro",
""
],
[
"Arita",
"Ryotaro",
""
],
[
"Aoki",
"Hideo",
""
]
] |
0706.3110 | Harald Krueger | Harald Krueger, Markus Landgraf, Nicolas Altobelli, Eberhard Gruen | Interstellar Dust in the Solar System | 8 pages, 4 figures. Space Science Reviews, in press | null | 10.1007/s11214-007-9181-7 | null | astro-ph | null | The Ulysses spacecraft has been orbiting the Sun on a highly inclined ellipse
almost perpendicular to the ecliptic plane (inclination 79 deg, perihelion
distance 1.3 AU, aphelion distance 5.4 AU) since it encountered Jupiter in
1992. The in-situ dust detector on board continuously measured interstellar
dust grains with masses up to 10^-13 kg, penetrating deep into the solar
system. The flow direction is close to the mean apex of the Sun's motion
through the solar system and the grains act as tracers of the physical
conditions in the local interstellar cloud (LIC). While Ulysses monitored the
interstellar dust stream at high ecliptic latitudes between 3 and 5 AU,
interstellar impactors were also measured with the in-situ dust detectors on
board Cassini, Galileo and Helios, covering a heliocentric distance range
between 0.3 and 3 AU in the ecliptic plane. The interstellar dust stream in the
inner solar system is altered by the solar radiation pressure force,
gravitational focussing and interaction of charged grains with the time varying
interplanetary magnetic field. We review the results from in-situ interstellar
dust measurements in the solar system and present Ulysses' latest interstellar
dust data. These data indicate a 30 deg shift in the impact direction of
interstellar grains w.r.t. the interstellar helium flow direction, the reason
of which is presently unknown.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:56:33 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Krueger",
"Harald",
""
],
[
"Landgraf",
"Markus",
""
],
[
"Altobelli",
"Nicolas",
""
],
[
"Gruen",
"Eberhard",
""
]
] |
0706.3111 | Cheng-ping Huang | Yi-qiang Qin, Chao Zhang, and Yong-yuan Zhu | Wave-front engineering by Huygens-Fresnel principle for nonlinear
optical interactions in domain engineered structures | 15 pages, 3 figures | Phys.Rev.Lett. 100, 063902 (2008) | 10.1103/PhysRevLett.100.063902 | null | physics.optics | null | The wave-front engineering for nonlinear optical interactions was discussed.
Using Huygens-Fresnel principle we developed a general theory and technique for
domain engineering with conventional quasi-phase-matching structures being the
special cases. By Fourier analysis we put forward the concept of local
quasi-phase matching, which suggests that the quasi-phase matching is fulfilled
only locally not globally. Experiments on focal effect of second-harmonic wave
agreed well with the theoretical prediction. The proposed scheme combines three
optical functions: generation, focusing and beam splitting of second-harmonic
wave, thus making the device more compact. Further the proposed scheme can be
used to perform the integration of multi-functional optical properties in
nonlinear photonics, as well as expand the use of nonlinear optical devices.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:44:07 GMT"
}
] | 2009-04-06T00:00:00 | [
[
"Qin",
"Yi-qiang",
""
],
[
"Zhang",
"Chao",
""
],
[
"Zhu",
"Yong-yuan",
""
]
] |
0706.3112 | Christoph A. Stephan | Romain Squellari, Christoph A. Stephan | Almost-Commutative Geometries Beyond the Standard Model III: Vector
Doublets | null | J.Phys.A40:10685-10698,2007 | 10.1088/1751-8113/40/34/020 | null | hep-th | null | We will present a new extension of the standard model of particle physics in
its almostcommutative formulation. This extension has as its basis the algebra
of the standard model with four summands [11], and enlarges only the particle
content by an arbitrary number of generations of left-right symmetric doublets
which couple vectorially to the U(1)_YxSU(2)_w subgroup of the standard model.
As in the model presented in [8], which introduced particles with a new colour,
grand unification is no longer required by the spectral action. The new model
may also possess a candidate for dark matter in the hundred TeV mass range with
neutrino-like cross section.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 09:44:30 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Squellari",
"Romain",
""
],
[
"Stephan",
"Christoph A.",
""
]
] |
0706.3113 | Vivienne Wild | Vivienne Wild (1), Guinevere Kauffmann (1), Tim Heckman (2),
St\'ephane Charlot (3), Gerard Lemson (4), Jarle Brinchmann (5), Tim Reichard
(2), Anna Pasquali (6) ((1) MPA-Garching, (2) JHU, (3) IAP-Paris, (4) MPE,
(5) Porto, (6) MPIA) | Bursty stellar populations and obscured AGN in galaxy bulges | 27 pages, submitted to MNRAS. Due to astro-ph size restrictions 6
figures in appendix are available as separate files. Full version, with full
resolution figures available at
http://www.mpa-garching.mpg.de/~vwild/HDelta/Hd_PCAmethod.pdf | null | 10.1111/j.1365-2966.2007.12256.x | null | astro-ph | null | [Abridged] We investigate trends between the recent star formation history
and black hole growth in galaxy bulges in the Sloan Digital Sky Survey (SDSS).
The galaxies lie at 0.01<z<0.07 where the fibre aperture covers only the
central 0.6-4.0kpc diameter of the galaxy. We find strong trends between black
hole growth, as measured by dust-attenuation-corrected OIII luminosity, and the
recent star formation history of the bulges. We conclude that our results
support the popular hypothesis for black hole growth occurring through gas
inflow into the central regions of galaxies, followed by a starburst and
triggering of the AGN. However, while this is a significant pathway for the
growth of black holes, it is not the dominant one in the present-day Universe.
More unspectacular processes are apparently responsible for the majority of
this growth.
In order to arrive at these conclusions we have developed a set of new high
signal-to-noise ratio (SNR) optical spectral indicators, designed to allow a
detailed study of stellar populations which have undergone recent enhanced star
formation. Working in the rest-frame wavelength range 3750-4150AA, ideally
suited to many recent and ongoing spectroscopic surveys at low and high
redshift, the first two indices are equivalent to the previously well studied
4000AA break strength and Hdelta equivalent width. The primary advantage of
this new method is a greatly improved SNR for the latter index, allowing the
present study to use spectra with SNR-per-pixel as low as 8.
| [
{
"version": "v1",
"created": "Thu, 21 Jun 2007 10:07:38 GMT"
}
] | 2016-08-14T00:00:00 | [
[
"Wild",
"Vivienne",
""
],
[
"Kauffmann",
"Guinevere",
""
],
[
"Heckman",
"Tim",
""
],
[
"Charlot",
"Stéphane",
""
],
[
"Lemson",
"Gerard",
""
],
[
"Brinchmann",
"Jarle",
""
],
[
"Reichard",
"Tim",
""
],
[
"Pasquali",
"Anna",
""
]
] |
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