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list | update_date
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sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.1414 | W. Prellier | M.P. Singh, C. Grygiel, W.C. Sheets, P. Boullay, M. Hervieu, W.
Prellier, B. Mercey, Ch. Simon and B. Raeau | Absence of long-range Ni/Mn ordering in ferromagnetic La2NiMnO6 thin
films | To be published in Applied Physics Letters | Appl. Phys. Lett. 91 (2007) 012503 | 10.1063/1.2753715 | null | cond-mat.mtrl-sci cond-mat.str-el | null | Epitaxial La2NiMnO6 thin films have been grown on (001)-oriented SrTiO3 using
the PLD technique. The thin films are semiconducting and FM with a TC close to
270K, a coercive field of 920Oe, and a saturation magnetization of 5muB per
f.u. TEM, conducted at RT, reveals a majority phase having "I-centered"
structure with a=c=1.4asub and b=2asub along with a minority phase-domains
having "P-type" structure (asub being the lattice parameter of the perovskite
structure). A discusion on the presence of Ni/Mn long-range ordering, in light
of recent literature on double perovskites La2NiMnO6 is presented.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:00:09 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Singh",
"M. P.",
""
],
[
"Grygiel",
"C.",
""
],
[
"Sheets",
"W. C.",
""
],
[
"Boullay",
"P.",
""
],
[
"Hervieu",
"M.",
""
],
[
"Prellier",
"W.",
""
],
[
"Mercey",
"B.",
""
],
[
"Simon",
"Ch.",
""
],
[
"Raeau",
"B.",
""
]
] |
0706.1415 | Teiko Heinonen | Paul Busch, Teiko Heinosaari | Approximate joint measurements of qubit observables | 20 pages, 2 figures, minor corrections | Quantum Inf. Comp. 8:0797-0818, (2008) | null | null | quant-ph | null | Joint measurements of qubit observables have recently been studied in
conjunction with quantum information processing tasks such as cloning.
Considerations of such joint measurements have until now been restricted to a
certain class of observables that can be characterized by a form of covariance.
Here we investigate conditions for the joint measurability of arbitrary pairs
of qubit observables. For pairs of noncommuting sharp qubit observables, a
notion of approximate joint measurement is introduced. Optimal approximate
joint measurements are shown to lie in the class of covariant joint
measurements. The marginal observables found to be optimal approximators are
generally not among the coarse-grainings of the observables to be approximated.
This yields scope for the improvement of existing joint measurement schemes.
Both the quality of the approximations and the intrinsic unsharpness of the
approximators are shown to be subject to Heisenberg-type uncertainty relations.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:21:35 GMT"
},
{
"version": "v2",
"created": "Thu, 3 Apr 2008 13:28:24 GMT"
}
] | 2008-06-10T00:00:00 | [
[
"Busch",
"Paul",
""
],
[
"Heinosaari",
"Teiko",
""
]
] |
0706.1416 | Michael Heller | Michael Heller, Zdzislaw Odrzygozdz, Leszek Pysiak, Wieslaw Sasin | Anatomy of Malicious Singularities | 16 pages in LaTex | null | 10.1063/1.2779955 | null | gr-qc | null | As well known, the b-boundaries of the closed Friedman world model and of
Schwarzschild solution consist of a single point. We study this phenomenon in a
broader context of differential and structured spaces. We show that it is an
equivalence relation $\rho $, defined on the Cauchy completed total space
$\bar{E}$ of the frame bundle over a given space-time, that is responsible for
this pathology. A singularity is called malicious if the equivalence class
$[p_0]$ related to the singularity remains in close contact with all other
equivalence classes, i.e., if $p_0 \in \mathrm{cl}[p]$ for every $p \in E$. We
formulate conditions for which such a situation occurs. The differential
structure of any space-time with malicious singularities consists only of
constant functions which means that, from the topological point of view,
everything collapses to a single point. It was noncommutative geometry that was
especially devised to deal with such situations. A noncommutative algebra on
$\bar{E}$, which turns out to be a von Neumann algebra of random operators,
allows us to study probabilistic properties (in a generalized sense) of
malicious singularities. Our main result is that, in the noncommutative regime,
even the strongest singularities are probabilistically irrelevant.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:42:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Heller",
"Michael",
""
],
[
"Odrzygozdz",
"Zdzislaw",
""
],
[
"Pysiak",
"Leszek",
""
],
[
"Sasin",
"Wieslaw",
""
]
] |
0706.1417 | Klaus Michael Indlekofer | K. M. Indlekofer, R. N\'emeth, and J. Knoch | Spatially resolved THz response as a characterization concept for
nanowire FETs | null | null | null | null | cond-mat.other | null | In this paper, we propose a THz probe technique to obtain spatially resolved
information about the electronic spectra inside nanowire-based FETs. This
spectroscopic approach employs a segmented multi-gate design for the local
detection of quantum transitions between few-electron states within the FET
channel. We simulate the intra-band THz response of such devices by means of a
many-body quantum approach, taking quantization and Coulomb interaction effects
into account. The obtained simulation results demonstrate the capabilities of
the proposed technique which go beyond the limitations of standard
characterization methods.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:44:21 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Indlekofer",
"K. M.",
""
],
[
"Németh",
"R.",
""
],
[
"Knoch",
"J.",
""
]
] |
0706.1418 | Rafi Mohd | Bernardo Lafuerza-Guillen and Mohd Rafi | Generalized Banach contraction in probabilistic metric/normed spaces | 13 pages | null | null | null | math.FA | null | In this paper, we present the generalization of B-contraction and
C-contraction due to Sehgal and Hicks respectively. We also study some
properties of C-contraction in probabilistic metric space.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:50:23 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Lafuerza-Guillen",
"Bernardo",
""
],
[
"Rafi",
"Mohd",
""
]
] |
0706.1419 | Florent Benaych-Georges | Serban Belinschi, Florent Benaych-Georges (PMA), Alice Guionnet
(UMPA-ENSL) | Regularization by free additive convolution, square and rectangular
cases | 43 pages, to appear in Complex Analysis and Operator Theory | null | null | null | math.PR | null | The free convolution is the binary operation on the set of probability
measures on the real line which allows to deduce, from the individual spectral
distributions, the spectral distribution of a sum of independent unitarily
invariant square random matrices or of a sum of free operators in a non
commutative probability space. In the same way, the rectangular free
convolution allows to deduce, from the individual singular distributions, the
singular distribution of a sum of independent unitarily invariant rectangular
random matrices. In this paper, we consider the regularization properties of
these free convolutions on the whole real line. More specifically, we try to
find continuous semigroups $(\mu_t)$ of probability measures such that $\mu_0$
is the Dirac mass at zero and such that for all positive $t$ and all
probability measure $\nu$, the free convolution of $\mu_t$ with $\nu$ (or, in
the rectangular context, the rectangular free convolution of $\mu_t$ with
$\nu$) is absolutely continuous with respect to the Lebesgue measure, with a
positive analytic density on the whole real line. In the square case, we prove
that in semigroups satisfying this property, no measure can have a finite
second moment, and we give a sufficient condition on semigroups to satisfy this
property, with examples. In the rectangular case, we prove that in most cases,
for $\mu$ in a continuous rectangular-convolution-semigroup, the rectangular
convolution of $\mu$ with $\nu$ either has an atom at the origin or doesn't put
any mass in a neighborhood of the origin, thus the expected property does not
hold. However, we give sufficient conditions for analyticity of the density of
the rectangular convolution of $\mu$ with $\nu$ except on a negligible set of
points, as well as existence and continuity of a density everywhere.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:52:32 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 2008 15:52:21 GMT"
}
] | 2008-06-05T00:00:00 | [
[
"Belinschi",
"Serban",
"",
"PMA"
],
[
"Benaych-Georges",
"Florent",
"",
"PMA"
],
[
"Guionnet",
"Alice",
"",
"UMPA-ENSL"
]
] |
0706.1420 | Arkadiy Baltenkov | A. S. Baltenkov | Asymptotic form of molecular continuum wave function for system of
non-overlapping atomic potentials | null | null | null | null | physics.atom-ph physics.atm-clus | null | The asymptotic behavior of the molecular continuum wave function has been
analyzed within a model of non-overlapping atomic potentials. It is been shown
that the representation of the wave function far from a molecule as a plane
wave and single spherical wave emitted by the molecular center cannot be
corrected. Because of the multicenter character of the problem, the asymptotic
form of the wave function must contain N spherical waves with centers at the
nuclei of the N atoms that form the molecule. A method of partial waves for a
spherically non-symmetrical target is considered for the simplest multicenter
target formed by two non-overlapping potentials. The results are compared with
those obtained within the single spherical wave approximation. It has been
shown that the use of this approximation results in significant mistakes in
differential and total cross sections of electron elastic scattering by a
target.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 08:53:48 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Baltenkov",
"A. S.",
""
]
] |
0706.1421 | Pierluigi Belli | R. Bernabei (1), P. Belli (1), F. Montecchia (1), F. Nozzoli (1), F.
Cappella (2), A. Incicchitti (2), D. Prosperi (2), R. Cerulli (3), C.J. Dai
(4), H.L. He (4), H.H. Kuang (4), J.M. Ma (4), X.D. Sheng (4), Z.P. Ye (4)
((1) Univ. and INFN Roma Tor Vergata, (2) Univ. and INFN Roma, (3) INFN LNGS,
(4) IHEP Beijing) | On electromagnetic contributions in WIMP quests | 14 pages, 6 figures, 2 tables, Int. J. Mod. Phys. A (in publication) | Int.J.Mod.Phys.A22:3155-3168,2007 | 10.1142/S0217751X07037093 | null | astro-ph | null | The effect pointed out by A. B. Migdal in the 40's (hereafter named Migdal
effect) has so far been usually neglected in the direct searches for WIMP Dark
Matter candidates. This effect consists in the ionization and the excitation of
bound atomic electrons induced by the recoiling atomic nucleus. In the present
paper the related theoretical arguments are developed and some consequences of
the proper accounting for this effect are discussed by some examples of
practical interest.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 09:01:01 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Bernabei",
"R.",
""
],
[
"Belli",
"P.",
""
],
[
"Montecchia",
"F.",
""
],
[
"Nozzoli",
"F.",
""
],
[
"Cappella",
"F.",
""
],
[
"Incicchitti",
"A.",
""
],
[
"Prosperi",
"D.",
""
],
[
"Cerulli",
"R.",
""
],
[
"Dai",
"C. J.",
""
],
[
"He",
"H. L.",
""
],
[
"Kuang",
"H. H.",
""
],
[
"Ma",
"J. M.",
""
],
[
"Sheng",
"X. D.",
""
],
[
"Ye",
"Z. P.",
""
]
] |
0706.1422 | Patricia Gaitan | Patricia Gaitan (LATP) | Inverse Conductivity Problem for a Parabolic Equation using a Carlemen
Estimate with one Observation | null | null | null | null | math.AP | null | For the heat equation in a bounded domain we give a stability result for a
smooth diffusion coefficient. The key ingredients are a global Carleman-type
estimate, a Poincar\'e-type estimate and an energy estimate with a single
observation acting on a part of the boundary.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 09:02:24 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Gaitan",
"Patricia",
"",
"LATP"
]
] |
0706.1423 | Florian Kaempfer | C. Br\"ugger, C.P. Hofmann, F. K\"ampfer, M. Moser, M. Pepe, U.-J.
Wiese | Spiral phases and two-particle bound states from a systematic low-energy
effective theory for magnons, electrons, and holes in an antiferromagnet | 2 Pages; Proc. of SCES'07, Houston | Physica B 403 (2008) 1447 | 10.1016/j.physb.2007.10.168 | null | cond-mat.str-el | null | We have constructed a systematic low-energy effective theory for hole- and
electron-doped antiferromagnets, where holes reside in momentum space pockets
centered at $(\pm\frac{\pi}{2a},\pm\frac{\pi}{2a})$ and where electrons live in
pockets centered at $(\frac{\pi}{a},0)$ or $(0,\frac{\pi}{a})$. The effective
theory is used to investigate the magnon-mediated binding between two holes or
two electrons in an otherwise undoped system. We derive the one-magnon exchange
potential from the effective theory and then solve the corresponding
two-quasiparticle Schr\"odinger equation. As a result, we find bound state wave
functions that resemble $d_{x^2-y^2}$-like or $d_{xy}$-like symmetry. We also
study possible ground states of lightly doped antiferromagnets.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:45:23 GMT"
}
] | 2008-03-08T00:00:00 | [
[
"Brügger",
"C.",
""
],
[
"Hofmann",
"C. P.",
""
],
[
"Kämpfer",
"F.",
""
],
[
"Moser",
"M.",
""
],
[
"Pepe",
"M.",
""
],
[
"Wiese",
"U. -J.",
""
]
] |
0706.1424 | Goetz Seibold | G. Seibold, F. Becca and J. Lorenzana | Theory of antibound states in partially filled narrow band systems | 4 pages, 3 figures | Phys. Rev. Lett. 100, 016405 (2008) | 10.1103/PhysRevLett.100.016405 | null | cond-mat.str-el | null | We present a theory of the dynamical two-particle response function in the
Hubbard model based on the time-dependent Gutzwiller approximation. The results
are in excellent agreement with exact diagonalization on small clusters and
give reliable results even for high densities, where the usual ladder
approximation breaks down. We apply the theory to the computation of antibound
states relevant for Auger spectroscopy and cold atom physics. A special bonus
of the theory is its computational simplicity.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 09:40:49 GMT"
}
] | 2008-06-16T00:00:00 | [
[
"Seibold",
"G.",
""
],
[
"Becca",
"F.",
""
],
[
"Lorenzana",
"J.",
""
]
] |
0706.1425 | Sanjeev Kumar | Sanjeev Kumar, Arno P. Kampf | Combined Effect of Bond- and Potential-Disorder in Half-Doped Manganites | 4 pages, 3 figures, published version | Phys. Rev. Lett. 100, 076406 (2008) | 10.1103/PhysRevLett.100.076406 | null | cond-mat.str-el cond-mat.dis-nn | null | We analyze the effects of both bond- and potential-disorder in the vicinity
of a first-order metal insulator transition in a two-band model for manganites
using a real-space Monte Carlo method. Our results reveal a novel
charge-ordered state coexisting with spin-glass behavior. We provide the basis
for understanding the phase diagrams of half-doped manganites, and contrast the
effects of bond- and potential-disorder and the combination of both.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 09:54:32 GMT"
},
{
"version": "v2",
"created": "Fri, 23 May 2008 14:13:36 GMT"
}
] | 2008-05-23T00:00:00 | [
[
"Kumar",
"Sanjeev",
""
],
[
"Kampf",
"Arno P.",
""
]
] |
0706.1426 | Kazushige Machida | K. Machida, M. Ichioka | Is Sr2RuO4 a triplet superconductor? | null | null | null | null | cond-mat.supr-con | null | The field dependence of the specific heat \gamma(H) at lower temperatures in
Sr2RuO4 is analyzed by solving microscopic Eilenberger equation numerically. We
find that systematic \gamma(H) behaviors from a concaved \sqrt H to a convex
H^{\alpha} (\alpha>1) under H orientation change are understood by taking
account of the Pauli paramagnetic effect. The magnetizations are shown to be
consistent with it. This implies either a singlet pairing or a triplet one with
d-vector locked in the basal plane, which allows us to explain other mysteries
of this compound in a consistent way.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:03:24 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Machida",
"K.",
""
],
[
"Ichioka",
"M.",
""
]
] |
0706.1427 | Farvah Mahmoudi | M. R. Ahmady, F. Mahmoudi | Estimating the annihilation decay B_s -> rho gamma with factorization | 9 pages, 1 figure | Mod.Phys.Lett.A24:3173-3181,2009 | 10.1142/S0217732309032150 | MTA-PHYS-0704 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The branching ratio for the rare two-body B_s -> rho gamma decay is
calculated using the factorization assumption. This transition is dominated by
the annihilation diagrams and, in principle, prone to receiving substantial
contributions from new physics. We estimate Br(B_s -> rho gamma) = 1.6 x 10^-9
within the Standard Model and investigate the sensitivity of this decay mode to
the effects of two new physics scenarios: vector quark model and supersymmetry.
Our results indicate that the shift in branching ratio is at most around 10%
with the addition of vector quarks and is negligibly small in the constrained
minimal supersymmetric extension of the Standard Model.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:04:16 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Dec 2009 00:57:18 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Ahmady",
"M. R.",
""
],
[
"Mahmoudi",
"F.",
""
]
] |
0706.1428 | Patrick Weber | Patrick Weber | SILEM : a new gaseous detector with integrated x-y readout plane | 9 pages | null | null | null | physics.ins-det | null | This works reports on gaseous detectors developments made in the frame of the
EXO double-beta decay experiment. LEM (Large Electron Multiplication) are
electron amplification grids based on GEM. They were developed in Neuchatel and
showed remarquable resistance to sparks. The new SILEM grid combines the
properties of the standard LEM with a micropatterned x-y readout plane on one
of the grid side. It allows thus the amplification of the primary electrons and
their position determination in the x-y plane.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:10:01 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Weber",
"Patrick",
""
]
] |
0706.1429 | Stephen Clark | Stephen Clark (CEC M De Stael) | Q-Ball Condensation | null | null | null | null | hep-th hep-ph | null | Q-balls arise in particle theories with U(1) global symmetry. The coupling of
the corresponding scalar field to fermions leads to Q-ball evaporation. In this
paper we consider the oposite problem, the case where a Q-ball absorbs
particles to grow. In particular we shall use the exact quantum mechanical
description of fermions interacting with a Q-ball to solve the problem. Results
show that Q-ball condensation can be another mechanism for Q-ball creation.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:12:44 GMT"
},
{
"version": "v2",
"created": "Wed, 4 Jul 2007 14:09:03 GMT"
}
] | 2007-07-05T00:00:00 | [
[
"Clark",
"Stephen",
"",
"CEC M De Stael"
]
] |
0706.1430 | Tomoka Tosaki | T. Tosaki, R. Miura, T. Sawada, N. Kuno, K. Nakanishi, K. Kohno, S. K.
Okumura, R. Kawabe | Arc-like distribution of high CO(J=3-2)/CO(J=1-0) ratio gas surrounding
the central star cluster of the supergiant HII region NGC 604 | 4 pages, 4 figures. The Astrophysical Journal Letters, in press | Astrophys.J.664:L27-LL30, 2007 | 10.1086/520624 | null | astro-ph | null | We report the discovery of a high CO(J=3-2)/CO(J=1-0) ratio gas with an
arc-like distribution (``high-ratio gas arc'') surrounding the central star
cluster of the supergiant HII region NGC 604 in the nearby spiral galaxy M 33,
based on multi-J CO observations of a 5' $\times$ 5' region of NGC 604
conducted using the ASTE 10-m and NRO 45-m telescopes. The discovered
``high-ratio gas arc'' extends to the south-east to north-west direction with a
size of $\sim$ 200 pc. The western part of the high-ratio gas arc closely
coincides well with the shells of the HII regions traced by H$\alpha$ and radio
continuum peaks. The CO(J=3-2)/CO(J=1-0) ratio, R_{3-2/1-0}, ranges between 0.3
and 1.2 in the observed region, and the R_{3-2/1-0} values of the high-ratio
gas arc are around or higher than unity, indicating very warm (T_kin > 60 K)
and dense (n(H_2) > 10^{3-4} cm^{-3}) conditions of the high-ratio gas arc. We
suggest that the dense gas formation and second-generation star formation occur
in the surrounding gas compressed by the stellar wind and/or supernova of the
first-generation stars of NGC 604, i.e., the central star cluster of NGC 604.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:22:27 GMT"
}
] | 2011-06-21T00:00:00 | [
[
"Tosaki",
"T.",
""
],
[
"Miura",
"R.",
""
],
[
"Sawada",
"T.",
""
],
[
"Kuno",
"N.",
""
],
[
"Nakanishi",
"K.",
""
],
[
"Kohno",
"K.",
""
],
[
"Okumura",
"S. K.",
""
],
[
"Kawabe",
"R.",
""
]
] |
0706.1431 | Henning Vahlbruch | Henning Vahlbruch, Moritz Mehmet, Nico Lastzka, Boris Hage, Simon
Chelkowski, Alexander Franzen, Stefan Gossler, Karsten Danzmann and Roman
Schnabel | Observation of squeezed light with 10dB quantum noise reduction | 10 pages, 4 figures | PRL 100, 033602 (2008) | 10.1103/PhysRevLett.100.033602 | null | quant-ph | null | Squeezing of light's quantum noise requires temporal rearranging of photons.
This again corresponds to creation of quantum correlations between individual
photons. Squeezed light is a non-classical manifestation of light with great
potential in high-precision quantum measurements, for example in the detection
of gravitational waves. Equally promising applications have been proposed in
quantum communication. However, after 20 years of intensive research doubts
arose whether strong squeezing can ever be realized as required for eminent
applications. Here we show experimentally that strong squeezing of light's
quantum noise is possible. We reached a benchmark squeezing factor of 10 in
power (10dB). Thorough analysis reveals that even higher squeezing factors will
be feasible in our setup.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:15:11 GMT"
}
] | 2008-01-24T00:00:00 | [
[
"Vahlbruch",
"Henning",
""
],
[
"Mehmet",
"Moritz",
""
],
[
"Lastzka",
"Nico",
""
],
[
"Hage",
"Boris",
""
],
[
"Chelkowski",
"Simon",
""
],
[
"Franzen",
"Alexander",
""
],
[
"Gossler",
"Stefan",
""
],
[
"Danzmann",
"Karsten",
""
],
[
"Schnabel",
"Roman",
""
]
] |
0706.1432 | Zhang Chengwu | Chengwu Zhang, Lixin Xu, Yongli Ping and Hongya Liu | Reconstruction of 5D Cosmological Model From Recent Observations | 7 pages, 3 figs, Accept by IJMPD | Int.J.Mod.Phys.D16:1573-1579,2007 | 10.1142/S021827180701095X | null | astro-ph | null | We use a parameterized equation of state (EOS) of dark energy to a 5D
Ricci-flat cosmological solution and suppose the universe contains two major
components: dark matter and dark energy. Using the recent observational
datasets: the latest 182 type Ia Supernovae Gold data, the 3-year WMAP CMB
shift parameter and the SDSS baryon acoustic peak, we obtain the best fit
values of the EOS and two major components' evolution. We find that the best
fit EOS crossing -1 in the near past $z\simeq 0.07$, the present best fit value
of $w_x(0)<-1$ and for this model the universe experiences the acceleration at
about $z\simeq 0.5$.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:15:28 GMT"
}
] | 2009-06-23T00:00:00 | [
[
"Zhang",
"Chengwu",
""
],
[
"Xu",
"Lixin",
""
],
[
"Ping",
"Yongli",
""
],
[
"Liu",
"Hongya",
""
]
] |
0706.1433 | J. M. Bonnet-Bidaud | J.M. Bonnet-Bidaud, D. de Martino, M. Falanga, M. Mouchet and N.
Masetti | IGR J00234+6141 : a new INTEGRAL source identified as an Intermediate
polar | 6 pages, 7 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20077877 | null | astro-ph | null | Following an extensive survey of the galactic plane by the INTEGRAL
satellite, new hard X-ray sources are discovered with a significant fraction of
Cataclysmic Variables (CVs) among them. We report here the identification of
one of these hard X-ray sources, IGR J00234+6141, as an accreting magnetic
white dwarf of intermediate polar type. We analyse the high energy emission of
the INTEGRAL source using all available data and provide complementary optical
photometric and spectroscopic data obtained respectively in August and October
2006. Based on a refined INTEGRAL position, we confirm the proposed optical
identification. We clearly detect the presence of a 564 s periodic optical
modulation that we identify as the rotation of the white dwarf. The analysis of
the optical spectrum also demonstrates that the emission lines show a
modulation in radial velocity with an orbital period of Porb = (4.033 +/-
0.005) hr. The two periodicities indicate that IGR00234+6141 is a magnetic CV
of the intermediate polar type. This is one of the faintest and hardest sources
of this type detected by INTEGRAL. This confirms earlier conclusions that IPs
contribute significantly to the population of galactic X-ray sources and
represent a significant fraction of the high energy background.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:23:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bonnet-Bidaud",
"J. M.",
""
],
[
"de Martino",
"D.",
""
],
[
"Falanga",
"M.",
""
],
[
"Mouchet",
"M.",
""
],
[
"Masetti",
"N.",
""
]
] |
0706.1434 | Ascar Aringazin | V.D. Krevchik, T.V. Novikov, Yu. I. Dahnovsky, M.B. Semenov, E.V.
Shcherbakova, Kenji Yamamoto | Nonlinear Dynamics of Infectious Diseases Transfer with Possible
Applications for Tubercular Infection | 17 pages, 5 figures, PDF only | null | null | null | physics.med-ph physics.data-an | null | In this paper, we model a nonlinear dynamics of infectious diseases transfer.
Particularly, we study possible applications to tubercular infection in models
with different profiles (peak values) of the population density dependence on
spatial coordinates. Our approach is based on the well known method of
instantons which has been used by the authors to describe kinetics of adiabatic
chemical reactions as a function of the heat-bath temperature and other system
parameters. In our approach, we use "social temperature" T as one of the
controlling parameters. Increase of T leads to acceleration of the infectious
diseases transfer. The "blockage" effect for the infectious diseases transfer
has been demonstrated in the case when peak values (in the population density)
are equal to one and under condition that the "social temperature" is low.
Existence of such effect essentially depends from environment "activity"
(social and prophylactic). Results of our modeling qualitatively meet the
tuberculosis dynamic spread data in Penza region of Russia.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:25:47 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Krevchik",
"V. D.",
""
],
[
"Novikov",
"T. V.",
""
],
[
"Dahnovsky",
"Yu. I.",
""
],
[
"Semenov",
"M. B.",
""
],
[
"Shcherbakova",
"E. V.",
""
],
[
"Yamamoto",
"Kenji",
""
]
] |
0706.1435 | Gautam Bhattacharya Professor | J.S. Bhattacharyya and Gautam Bhattacharya | A Critical String Theory in 3+1 Dimensions | Reference and notes added to previous version | null | null | null | hep-th | null | Redefining the vacuum state of a free twofold N=1 covariant supersymmetric
string action as the one with all the world sheet fermionic excited states
occupied, makes the theory anomaly free in D=4 with Minkowski signature. The
theory thus describes a critical string in 3+1 dimensions as opposed to earlier
N=2 supersymmetric theories describing a 2+2 dimensional target space. While in
the NS sector the spectrum basically resembles the same for the standard N=1
superstring theory with one of the $N$ species in the background, in the R
sector both the species of fermions and superconformal ghosts are required to
describe the relevant spin operators to describe the fermion spectra. A crucial
difference from D=10 case is that the fermion states are Dirac particles
instead of Majorana-Weyl. Even though the full spectrum of the theory contains
both bosons and fermions of various spin, there is no space-time supersymmetry
due to obvious lack of triality.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:30:40 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Jun 2007 08:44:29 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Bhattacharyya",
"J. S.",
""
],
[
"Bhattacharya",
"Gautam",
""
]
] |
0706.1436 | George Lazarides | George Lazarides (Aristotle U., Thessaloniki) | Hybrid inflation followed by modular inflation | 13 pages including 3 figures, uses ws-ijmpa.cls, minor corrections
included, talk given at the CTP Symposium on Supersymmetry at LHC:
Theoretical and Experimental Perspectives, British University in Egypt (BUE),
Cairo, 11-14 March 2007 (to appear in the proceedings) | Int.J.Mod.Phys.A22:5747-5759,2007 | 10.1142/S0217751X07038980 | UT-STPD-3/07 | hep-ph astro-ph | null | Inflationary models with a superheavy scale F-term hybrid inflation followed
by an intermediate scale modular inflation are considered. The restrictions on
the power spectrum P_R of curvature perturbation and the spectral index n_s
from the recent data within the power-law cosmological model with cold dark
matter and a cosmological constant can be met provided that the number of
e-foldings N_HI* suffered by the pivot scale k_*=0.002/Mpc during hybrid
inflation is suitably restricted. The additional e-foldings needed for solving
the horizon and flatness problems are generated by modular inflation with a
string axion as inflaton. For central values of P_R and n_s, the grand
unification scale comes out, in the case of standard hybrid inflation, close to
its supersymmetric value M_GUT=2.86 x 10^16 GeV, the relevant coupling constant
is relatively large (0.005-0.14), and N_HI* is between 10 and 21.7. In the
shifted [smooth] hybrid inflation case, the grand unification scale can be
identified with M_GUT for N_HI*=21 [N_HI*=18].
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 10:39:18 GMT"
},
{
"version": "v2",
"created": "Fri, 21 Sep 2007 16:24:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Lazarides",
"George",
"",
"Aristotle U., Thessaloniki"
]
] |
0706.1437 | Ido Kanter | Michael Rosenbluh, Yaara Aviad, Elad Cohen, Lev Khaykovich, Wolfgang
Kinzel, Evi Kopelowitz, Pinhas Yoskovits and Ido Kanter | Spiking Optical Patterns and Synchronization | null | null | 10.1103/PhysRevE.76.046207 | null | physics.optics physics.bio-ph | null | We analyze the time resolved spike statistics of a solitary and two mutually
interacting chaotic semiconductor lasers whose chaos is characterized by
apparently random, short intensity spikes. Repulsion between two successive
spikes is observed, resulting in a refractory period which is largest at laser
threshold. For time intervals between spikes greater than the refractory
period, the distribution of the intervals follows a Poisson distribution. The
spiking pattern is highly periodic over time windows corresponding to the
optical length of the external cavity, with a slow change of the spiking
pattern as time increases. When zero-lag synchronization between the two lasers
is established, the statistics of the nearly perfectly matched spikes are not
altered. The similarity of these features to those found in complex interacting
neural networks, suggests the use of laser systems as simpler physical models
for neural networks.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:01:43 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rosenbluh",
"Michael",
""
],
[
"Aviad",
"Yaara",
""
],
[
"Cohen",
"Elad",
""
],
[
"Khaykovich",
"Lev",
""
],
[
"Kinzel",
"Wolfgang",
""
],
[
"Kopelowitz",
"Evi",
""
],
[
"Yoskovits",
"Pinhas",
""
],
[
"Kanter",
"Ido",
""
]
] |
0706.1438 | Antonio De Nicola | Beniamino Cappelletti Montano, Antonio De Nicola, Giulia Dileo | 3-quasi-Sasakian manifolds | 17 pages, minor modifications, references updated | Ann. Glob. Anal. Geom. 33 (2008), 397-409. | 10.1007/s10455-007-9093-5 | null | math.DG | null | In the present paper we carry on a systematic study of 3-quasi-Sasakian
manifolds. In particular we prove that the three Reeb vector fields generate an
involutive distribution determining a canonical totally geodesic and Riemannian
foliation. Locally, the leaves of this foliation turn out to be Lie groups:
either the orthogonal group or an abelian one. We show that 3-quasi-Sasakian
manifolds have a well-defined rank, obtaining a rank-based classification.
Furthermore, we prove a splitting theorem for these manifolds assuming the
integrability of one of the almost product structures. Finally, we show that
the vertical distribution is a minimum of the corrected energy.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:13:47 GMT"
},
{
"version": "v2",
"created": "Sat, 16 Jun 2007 23:01:52 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Sep 2007 14:44:40 GMT"
},
{
"version": "v4",
"created": "Mon, 8 Oct 2007 15:52:27 GMT"
},
{
"version": "v5",
"created": "Fri, 12 Oct 2007 17:35:08 GMT"
}
] | 2008-04-29T00:00:00 | [
[
"Montano",
"Beniamino Cappelletti",
""
],
[
"De Nicola",
"Antonio",
""
],
[
"Dileo",
"Giulia",
""
]
] |
0706.1439 | F. Javier Garcia de Abajo | Mark R. Dennis, Nikolay I. Zheludev, and F. Javier Garcia de Abajo | The plasmon Talbot effect | null | Optics Express 15, 9692-9700 (2007) | 10.1364/OE.15.009692 | null | cond-mat.other | null | The plasmon analog of the self-imaging Talbot effect is described and
theoretically analyzed. Rich plasmon carpets containing hot spots are shown to
be produced by a row of periodically-spaced surface features. A row of holes
drilled in a metal film and illuminated from the back side is discussed as a
realizable implementation of this concept. Self-images of the row are produced,
separated from the original one by distances up to several hundreds of
wavelengths in the examples under consideration. The size of the image focal
spots is close to half a wavelength and the spot positions can be controlled by
changing the incidence direction of external illumination, suggesting the
possibility of using this effect (and its extension to non-periodic surface
features) for far-field patterning and for long-distance plasmon-based
interconnects in plasmonic circuits, energy transfer, and related phenomena.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:27:53 GMT"
},
{
"version": "v2",
"created": "Mon, 23 Jul 2007 06:55:12 GMT"
}
] | 2012-11-13T00:00:00 | [
[
"Dennis",
"Mark R.",
""
],
[
"Zheludev",
"Nikolay I.",
""
],
[
"de Abajo",
"F. Javier Garcia",
""
]
] |
0706.1440 | John Gracey | J.A. Gracey | One loop renormalization of the non-local gauge invariant operator min_U
(A^U_mu)^2 in QCD | 8 latex pages | Phys.Lett.B651:253-256,2007 | 10.1016/j.physletb.2007.06.021 | LTH 745 | hep-th | null | We compute the one loop anomalous dimension of the gauge invariant dimension
two operator min_U (A^U_mu)^2, where U is an element of the gauge group, by
exploiting Zwanziger's expansion of the operator in terms of gauge invariant
non-local n leg operators. The computation is performed in an arbitrary linear
covariant gauge and the cancellation of the gauge parameter in the final
anomalous dimension is demonstrated explicitly. The result is equivalent to the
one loop anomalous dimension of the local dimension two operator (A^a_mu)^2 in
the Landau gauge.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:30:31 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gracey",
"J. A.",
""
]
] |
0706.1441 | Farzaneh Sheidaei | F. Sheidaei, M. Bahmanabadi, M. Khakian Ghomi, S.M. Mahdavi, J.
Samimi, A. Anvari | On Shadow of the Moon in Extensive Air Shower Data | null | null | null | null | astro-ph | null | A new technique has been devised for the analysis of extensive air shower
data in observing the effect of the moon on this data. In this technique the
number of EAS events with arrival directions falling in error circles centered
about the moving moon is compared to the mean number of events falling in error
circles with centers randomly chosen in the sky. For any assumed angular radius
of the error circle the deficit in EAS event count in the direction of moon
i.e., Nsky-Nmoon which is a moon-related effect is interpreted as the shadow of
the moon. A simple theoretical model has been developed to relate Nsky to the
angular radius of the error circle and has been applied to the counts from the
moon's direction in order to extract the physical parameters of the shadow of
the moon. The technique and the theoretical model has been used on 1.7 *10^5
EAS events recorded at Alborz observatory.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:41:00 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Feb 2008 15:36:45 GMT"
}
] | 2008-02-24T00:00:00 | [
[
"Sheidaei",
"F.",
""
],
[
"Bahmanabadi",
"M.",
""
],
[
"Ghomi",
"M. Khakian",
""
],
[
"Mahdavi",
"S. M.",
""
],
[
"Samimi",
"J.",
""
],
[
"Anvari",
"A.",
""
]
] |
0706.1442 | Jan Kisiel | J. Holeczek, J. Kisiel, J. Syska, M. Zralek | Searching for New Physics in Future Neutrino Factory Experiments | 15 pages, 2 figures | Eur.Phys.J.C52:905-917,2007 | 10.1140/epjc/s10052-007-0420-6 | null | hep-ph | null | An extension of the New Standard Model, by introducing a mixing of the low
mass ``active'' neutrinos with heavy ones, or by any model with lepton flavor
violation, is considered. This leads to non-orthogonal neutrino production and
detection states and to modifications of neutrino oscillations in both, vacuum
and matter. The possibility of the discovery of such effects in current and
future neutrino oscillation experiments is discussed. First order approximation
formulas for the flavor transition probabilities in constant density matter,
for all experimentally available channels, are given. Numerical calculations of
flavor transition probabilities for two sets of New Physics parameters
describing a single ``effective'' heavy neutrino state, both satisfying present
experimental constraints, have been performed. Two energy ranges and several
baselines, assuming both the current ($\pm2\sigma$) and the expected in future
($\pm3%$) errors of the neutrino oscillation parameters are considered, keeping
their present central values. It appears that the biggest potential of the
discovery of the possible presence of any New Physics is pronounced in
oscillation channels in which $\nu_{e}$, $\nu_{\bar{e}}$ are not involved at
all, especially for two baselines, $L=3000 km$ and $L=7500 km$, which for other
reasons are also called ``magic'' for future $Neutrino Factory$ experiments.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:18:29 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Holeczek",
"J.",
""
],
[
"Kisiel",
"J.",
""
],
[
"Syska",
"J.",
""
],
[
"Zralek",
"M.",
""
]
] |
0706.1443 | Plamen Bozhilov | P. Bozhilov | Spin chain from membrane and the Neumann-Rosochatius integrable system | LaTeX, 16 pages, no figures; v2: 17 pages, title changed,
explanations and references added; v3: more explanations added; v4: typos
fixed, to appear in Phys. Rev. D | Phys.Rev.D76:106003,2007 | 10.1103/PhysRevD.76.106003 | null | hep-th nlin.SI | null | We find membrane configurations in AdS_4 x S^7, which correspond to the
continuous limit of the SU(2) integrable spin chain, considered as a limit of
the SU(3) spin chain, arising in N=4 SYM in four dimensions, dual to strings in
AdS_5 x S^5. We also discuss the relationship with the Neumann-Rosochatius
integrable system at the level of Lagrangians, comparing the string and
membrane cases.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:41:37 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 17:46:38 GMT"
},
{
"version": "v3",
"created": "Sun, 29 Jul 2007 20:28:14 GMT"
},
{
"version": "v4",
"created": "Thu, 20 Sep 2007 07:08:56 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bozhilov",
"P.",
""
]
] |
0706.1444 | Guanglian Zhang | Zongzhu Lin, Jie Xiao and Guanglian Zhang | Representations of tame quivers and affine canonical bases | 44 pages | null | null | null | math.QA | null | An integral PBW-basis of type $A_1^{(1)}$ has been constructed by Zhang [Z]
and Chen [C] using the Auslander-Reiten quiver of the Kronecker quiver. We
associate a geometric order to elements in this basis following an idea of
Lusztig [L1] in the case of finite type. This leads to an algebraic realization
of a bar-invariant basis of $\uq2$. For any affine symmetric type, we obtain an
integral PBW-basis of the generic composition algebra, by using an algebraic
construction of the integral basis for a tube in [DDX], an embedding of the
module category of the Kronecker quiver into the module category of the tame
quiver, and a list of the root vectors of indecomposable modules according to
the preprojective, regular, and preinjective components of the Auslander-Reiten
quiver of the tame quiver. When the basis elements are ordered to be compatible
with the geometric order given by the dimensions of the orbit varieties and the
extension varieties, we can show that the transition matrix between the
PBW-basis and a monomial basis is triangular with diagonal entries equal to 1.
Therefore we obtain a bar-invariant basis. By a orthogonalization for the
PBW-basis with the inner product, we finally give an algebraic way to realize
the canonical bases of the quantized enveloping algebras of all symmetric
affine Kac-Moody Lie algebras.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:42:46 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 15:11:39 GMT"
},
{
"version": "v3",
"created": "Mon, 9 Jul 2007 02:53:51 GMT"
}
] | 2007-07-09T00:00:00 | [
[
"Lin",
"Zongzhu",
""
],
[
"Xiao",
"Jie",
""
],
[
"Zhang",
"Guanglian",
""
]
] |
0706.1445 | Gabor Takacs | B. Pozsgay and G. Takacs | Form factors in finite volume I: form factor bootstrap and truncated
conformal space | 43 pages, 31 eps figures, LaTeX2e file. v2: main theoretical argument
substantially expanded and clarified, typos and references corrected | Nucl.Phys.B788:167-208,2008 | 10.1016/j.nuclphysb.2007.06.027 | ITP-Budapest Report No. 634 | hep-th cond-mat.other hep-lat | null | We describe the volume dependence of matrix elements of local fields to all
orders in inverse powers of the volume (i.e. only neglecting contributions that
decay exponentially with volume). Using the scaling Lee-Yang model and the
Ising model in a magnetic field as testing ground, we compare them to matrix
elements extracted in finite volume using truncated conformal space approach to
exact form factors obtained using the bootstrap method. We obtain solid
confirmation for the form factor bootstrap, which is different from all
previously available tests in that it is a non-perturbative and direct
comparison of exact form factors to multi-particle matrix elements of local
operators, computed from the Hamiltonian formulation of the quantum field
theory. We also demonstrate that combining form factor bootstrap and truncated
conformal space is an effective method for evaluating finite volume form
factors in integrable field theories over the whole range in volume.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:55:15 GMT"
},
{
"version": "v2",
"created": "Mon, 2 Jul 2007 11:04:27 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Pozsgay",
"B.",
""
],
[
"Takacs",
"G.",
""
]
] |
0706.1446 | Robi Peschanski | Robi Peschanski, Cyrille Marquet and Gregory Soyez | Non-forward Balitsky-Kovchegov equation and Vector Mesons | 4 pages,5 figures, Invited talk given at the DIS 2007 Conference,
Munich, Germany, April 2007 | null | null | null | hep-ph | null | Considering the Balitsky-Kovchegov QCD evolution equation in full momentum
space, we derive the travelling wave solutions expressing the nonlinear
saturation constraints on the dipole scattering amplitude at non-zero momentum
transfer. A phenomenological application to elastic vector meson production
shows the compatibility of data with the QCD prediction: an enhanced saturation
scale at intermediate momentum transfer.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 11:50:03 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Peschanski",
"Robi",
""
],
[
"Marquet",
"Cyrille",
""
],
[
"Soyez",
"Gregory",
""
]
] |
0706.1447 | Thomas Maschberger | Th. Maschberger and P. Kroupa | Star clusters as diaries of galaxies | 2 pages, 2 figures, To be published in the proceedings of "Pathways
Through an Eclectic Universe", Tenerife, April 23-27, 2007, ed. T. Mahoney,
A. Vazdekis, and J. Knapen | null | null | null | astro-ph | null | Most if not all stars form in star clusters. Thus the distribution of star
clusters preserves the information on the star formation history of a galaxy.
Massive clusters form only during episodes of high star formation activity
whereas periods of low star formation activity cannot produce them. We present
here the method of Maschberger & Kroupa (2007) to derive the star formation
history of a galaxy from its star-cluster content.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:03:45 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Maschberger",
"Th.",
""
],
[
"Kroupa",
"P.",
""
]
] |
0706.1448 | Maciej Ulas | Maciej Ulas | Rational points on certain hyperelliptic curves over finite fields | Revised version will appear in Bull. Polish Acad. Sci. Math | null | null | null | math.NT | null | Let $K$ be a field, $a, b\in K$ and $ab\neq 0$. Let us consider the
polynomials $g_{1}(x)=x^n+ax+b, g_{2}(x)=x^n+ax^2+bx$, where $n$ is a fixed
positive integer. In this paper we show that for each $k\geq 2$ the
hypersurface given by the equation \begin{equation*} S_{k}^{i}:
u^2=\prod_{j=1}^{k}g_{i}(x_{j}),\quad i=1, 2. \end{equation*} contains a
rational curve. Using the above and Woestijne's recent results \cite{Woe} we
show how one can construct a rational point different from the point at
infinity on the curves $C_{i}:y^2=g_{i}(x), (i=1, 2)$ defined over a finite
field, in polynomial time.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:03:50 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Ulas",
"Maciej",
""
]
] |
0706.1449 | Daniel Rogers | Daniel J. Rogers, Joshua C. Bienfang, Anastase Nakassis, Hai Xu and
Charles W. Clark | Detector dead-time effects and paralyzability in high-speed quantum key
distribution | null | null | 10.1088/1367-2630/9/9/319 | null | quant-ph | null | Recent advances in quantum key distribution (QKD) have given rise to systems
that operate at transmission periods significantly shorter than the dead times
of their component single-photon detectors. As systems continue to increase in
transmission rate, security concerns associated with detector dead times can
limit the production rate of sifted bits. We present a model of high-speed QKD
in this limit that identifies an optimum transmission rate for a system with
given link loss and detector response characteristics.
| [
{
"version": "v1",
"created": "Fri, 8 Jun 2007 22:08:21 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Rogers",
"Daniel J.",
""
],
[
"Bienfang",
"Joshua C.",
""
],
[
"Nakassis",
"Anastase",
""
],
[
"Xu",
"Hai",
""
],
[
"Clark",
"Charles W.",
""
]
] |
0706.1450 | Thomas Buervenich | Thomas J. Buervenich, Igor N. Mishustin, Walter Greiner | Nuclei embedded in an electron gas | 35 pages, latex+eps | Phys.Rev.C76:034310,2007 | 10.1103/PhysRevC.76.034310 | null | nucl-th | null | The properties of nuclei embedded in an electron gas are studied within the
relativistic mean-field approach. These studies are relevant for nuclear
properties in astrophysical environments such as neutron-star crusts and
supernova explosions. The electron gas is treated as a constant background in
the Wigner-Seitz cell approximation. We investigate the stability of nuclei
with respect to alpha and beta decay. Furthermore, the influence of the
electronic background on spontaneous fission of heavy and superheavy nuclei is
analyzed. We find that the presence of the electrons leads to stabilizing
effects for both $\alpha$ decay and spontaneous fission for high electron
densities. Furthermore, the screening effect shifts the proton dripline to more
proton-rich nuclei, and the stability line with respect to beta decay is
shifted to more neutron-rich nuclei. Implications for the creation and survival
of very heavy nuclear systems are discussed.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:13:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Buervenich",
"Thomas J.",
""
],
[
"Mishustin",
"Igor N.",
""
],
[
"Greiner",
"Walter",
""
]
] |
0706.1451 | Masashi Shiraishi | Megumi Ohishi, Masashi Shiraishi, Ryo Nouchi, Takayuki Nozaki, Teruya
Shinjo and Yoshishige Suzuki | Spin Injection into a Graphene Thin Film at Room Temperature | 12 pages, 3 figures | Japanese Journal of Applied Physics 46, L605-L607(Express Letters)
(2007). | 10.1143/JJAP.46.L605 | null | cond-mat.mtrl-sci | null | We demonstrate spin injection into a graphene thin film with high reliability
by using non-local magnetoresistance (MR) measurements, in which the electric
current path is completely separated from the spin current path. Using these
non-local measurements, an obvious MR effect was observed at room temperature;
and the MR effect was ascribed to magnetization reversal of ferromagnetic
electrodes. This result is a direct demonstration of spin injection into a
graphene thin film. Furthermore, this is the first report of spin injection
into molecules at room temperature.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:08:20 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ohishi",
"Megumi",
""
],
[
"Shiraishi",
"Masashi",
""
],
[
"Nouchi",
"Ryo",
""
],
[
"Nozaki",
"Takayuki",
""
],
[
"Shinjo",
"Teruya",
""
],
[
"Suzuki",
"Yoshishige",
""
]
] |
0706.1452 | Anders S. Mouritzen | Anders S. Mouritzen, Olga Smirnova, Stefanie Grafe, Rune Lausten and
Albert Stolow | Reconstructing vibrational states in warm molecules using four-wave
mixing with femtosecond laser pulses | 12 pages, 5 figures | null | null | null | quant-ph | null | We propose a method to reconstruct the vibrational quantum state of molecules
excited by a general excitation laser pulse. Unlike existing methods, we do not
require the molecules before excitation to be in a pure state, allowing us to
treat the important case of initially thermally excited molecules. Even if only
a single initial level is appreciably populated, initial levels with small
populations can still give major contributions to the unknown vibrational
state, making it essential to take them into account. In addition to the
excitation pulse, the method uses two incident, short laser pulses in a
non-co-linear geometry to create four-wave mixing in the molecules. The
measurements used in the reconstruction are spectra of the outgoing four-wave
mixing pulse at different time delays of the excitation laser pulse. An
important point is that the method does not require detailed knowledge of
molecular transition moments between excited states nor of any of the incoming
laser pulses, but circumvents this requirement by using one or more calibration
laser pulses in a separate experiment either before or after the main data are
recorded. The only requirements for the calibration laser pulses are that the
constant parts of their spectrums should together cover the spectral range of
the excitation laser pulse, and the constant part of each should have
sufficient spectral overlap with one other calibration pulse to populate two of
the same levels. Finally, we discuss the extension of the reconstruction method
in this paper to more general situations, hereby presenting the new idea of
quantum state reconstruction through perturbations with calibration.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:58:17 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Mouritzen",
"Anders S.",
""
],
[
"Smirnova",
"Olga",
""
],
[
"Grafe",
"Stefanie",
""
],
[
"Lausten",
"Rune",
""
],
[
"Stolow",
"Albert",
""
]
] |
0706.1453 | Marie-Bernadette Lepetit | Sylvain Landron (CRISMAT), Marie-Bernadette Lepetit (CRISMAT) | The crucial importance of the $t_{2g}$--$e_g$ hybridization in
transition metal oxides | null | null | 10.1103/PhysRevB.77.125106 | null | cond-mat.str-el | null | We studied the influence of the trigonal distortion of the regular octahedron
along the (111) direction, found in the $\rm CoO_2$ layers. Under such a
distortion the $t_{2g}$ orbitals split into one $a_{1g}$ and two degenerated
$e_g^\prime$ orbitals. We focused on the relative order of these orbitals.
Using quantum chemical calculations of embedded clusters at different levels of
theory, we analyzed the influence of the different effects not taken into
account in the crystalline field theory; that is metal-ligand hybridization,
long-range crystalline field, screening effects and orbital relaxation. We
found that none of them are responsible for the relative order of the $t_{2g}$
orbitals. In fact, the trigonal distortion allows a mixing of the $t_{2g}$ and
$e_g$ orbitals of the metallic atom. This hybridization is at the origin of the
$a_{1g}$--$e_g^\prime$ relative order and of the incorrect prediction of the
crystalline field theory.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:17:54 GMT"
},
{
"version": "v2",
"created": "Tue, 2 Oct 2007 09:02:36 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Landron",
"Sylvain",
"",
"CRISMAT"
],
[
"Lepetit",
"Marie-Bernadette",
"",
"CRISMAT"
]
] |
0706.1454 | Gerard Weisbuch | G\'erard Weisbuch, Vincent Buskens, Luat Vuong | Heterogeneity and Increasing Returns May Drive Socio-Economic
Transitions | null | null | null | null | q-fin.GN physics.soc-ph | null | There are clear benefits associated with a particular consumer choice for
many current markets. For example, as we consider here, some products might
carry environmental or `green' benefits. Some consumers might value these
benefits while others do not. However, as evidenced by myriad failed attempts
of environmental products to maintain even a niche market, such benefits do not
necessarily outweigh the extra purchasing cost. The question we pose is, how
can such an initially economically-disadvantaged green product evolve to hold
the greater share of the market? We present a simple mathematical model for the
dynamics of product competition in a heterogeneous consumer population. Our
model preassigns a hierarchy to the products, which designates the consumer
choice when prices are comparable, while prices are dynamically rescaled to
reflect increasing returns to scale. Our approach allows us to model many
scenarios of technology substitution and provides a method for generalizing
market forces. With this model, we begin to forecast irreversible trends
associated with consumer dynamics as well as policies that could be made to
influence transitions
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:38:44 GMT"
}
] | 2008-12-02T00:00:00 | [
[
"Weisbuch",
"Gérard",
""
],
[
"Buskens",
"Vincent",
""
],
[
"Vuong",
"Luat",
""
]
] |
0706.1455 | Francesc Fayos | F. Fayos, Ch. Teijon-Lumbreras | Geometrical locus of massive test particle orbits in the space of
physical parameters in Kerr space-time | 26 pages, 12 figures | Gen.Rel.Grav.40:2433-2460,2008 | 10.1007/s10714-008-0629-1 | null | gr-qc | null | Gravitational radiation of binary systems can be studied by using the
adiabatic approximation in General Relativity. In this approach a small
astrophysical object follows a trajectory consisting of a chained series of
bounded geodesics (orbits) in the outer region of a Kerr Black Hole,
representing the space time created by a bigger object. In our paper we study
the entire class of orbits, both of constant radius (spherical orbits), as well
as non-null eccentricity orbits, showing a number of properties on the physical
parameters and trajectories. The main result is the determination of the
geometrical locus of all the orbits in the space of physical parameters in Kerr
space-time. This becomes a powerful tool to know if different orbits can be
connected by a continuous change of their physical parameters. A discussion on
the influence of different values of the angular momentum of the hole is given.
Main results have been obtained by analytical methods.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:20:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Fayos",
"F.",
""
],
[
"Teijon-Lumbreras",
"Ch.",
""
]
] |
0706.1456 | Benoit Caillaud | Albert Benveniste (IRISA), Benoit Caillaud (IRISA), Roberto Passerone | A Generic Model of Contracts for Embedded Systems | null | null | null | null | cs.SE | null | We present the mathematical foundations of the contract-based model developed
in the framework of the SPEEDS project. SPEEDS aims at developing methods and
tools to support "speculative design", a design methodology in which
distributed designers develop different aspects of the overall system, in a
concurrent but controlled way. Our generic mathematical model of contract
supports this style of development. This is achieved by focusing on behaviors,
by supporting the notion of "rich component" where diverse (functional and
non-functional) aspects of the system can be considered and combined, by
representing rich components via their set of associated contracts, and by
formalizing the whole process of component composition.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:22:15 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 09:16:32 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Benveniste",
"Albert",
"",
"IRISA"
],
[
"Caillaud",
"Benoit",
"",
"IRISA"
],
[
"Passerone",
"Roberto",
""
]
] |
0706.1457 | Robi Peschanski | Guillaume Beuf, Robi Peschanski and Sebastian Sapeta | Universality of traveling waves with QCD running coupling | 4 pages, 3 figures,, Invited talk given at the DIS 2007 Conference,
Munich, Germany, April 2007; Change of title | null | 10.1103/PhysRevD.75.114001 | spht-07 | hep-ph | null | ``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio
Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be
theoretically obtained from universal ``traveling wave'' solutions of the
nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We
examine the similar mean-field predictions beyond leading-logarithmic order,
including running QCD coupling.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:24:11 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 12:15:20 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Beuf",
"Guillaume",
""
],
[
"Peschanski",
"Robi",
""
],
[
"Sapeta",
"Sebastian",
""
]
] |
0706.1458 | Marcelo Rozenberg | Pascal Lederer and Marcelo J. Rozenberg | Impurity scattering in strongly correlated metals close to the Mott
transition | 4 figures | null | null | null | cond-mat.str-el | null | This work explores a simple approximation to describe isolated impurity
scattering in a strongly correlated metal. The approximation combines
conventional one electron scattering theory and the Dynamic Mean Field Theory
to describe strong correlations in the host. It becomes exact in several
limits, including those of very weak and very strong impurity potentials.
Original electronic structure appears at the impurity site when the impurity
potential strength is moderate and the host is close to the Mott transition.
Our results may provide useful guidance for interpretation of scanning
tunneling microscopy experiments in strongly correlated systems.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:27:26 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Lederer",
"Pascal",
""
],
[
"Rozenberg",
"Marcelo J.",
""
]
] |
0706.1459 | Christian Schill | C. Schill (on behalf of the COMPASS collaboration) | Transversity Signals in Two-Hadron Production at COMPASS | Proceedings of DIS2007, Munich | Proc. of DIS 2007, Atlantis Press | 10.3360/dis.2007.105 | null | hep-ex | null | New results on single spin asymmetries of identified charged pion and kaon
pairs produced in deep-inelastic scattering of muons on a transversely
polarized 6LiD target are presented. The data were taken in the years 2003 and
2004 with the COMPASS spectrometer at CERN with a 160 GeV muon beam from the
CERN SPS accelerator. The asymmetries can be interpreted in the context of
transversity as a convolution of the chiral-odd interference fragmentation
function $H_1^\sphericalangle$ with the transverse spin distribution of quarks
$\Delta_Tq(x)$. The measured azimuthal target spin asymmetries on the deuteron
are compatible with zero within a small statistical error of about 1%.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:33:22 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Jun 2007 09:55:42 GMT"
}
] | 2011-01-13T00:00:00 | [
[
"Schill",
"C.",
"",
"on behalf of the COMPASS collaboration"
]
] |
0706.1460 | Gholamreza Jafari | G. R. Jafari, M. Sadegh Movahed, P. Noroozzadeh, A. Bahraminasab,
Muhammad Sahimi, F. Ghasemi, and M. Reza Rahimi Tabar | Uncertainty in the Fluctuations of the Price of Stocks | 5 pages, 5 figures. Accepted to appear in IJMPC | null | 10.1142/S0129183107011662 | null | q-fin.ST physics.data-an physics.soc-ph | null | We report on a study of the Tehran Price Index (TEPIX) from 2001 to 2006 as
an emerging market that has been affected by several political crises during
the recent years, and analyze the non-Gaussian probability density function
(PDF) of the log returns of the stocks' prices. We show that while the average
of the index did not fall very much over the time period of the study, its
day-to-day fluctuations strongly increased due to the crises. Using an approach
based on multiplicative processes with a detrending procedure, we study the
scale-dependence of the non-Gaussian PDFs, and show that the temporal
dependence of their tails indicates a gradual and systematic increase in the
probability of the appearance of large increments in the returns on approaching
distinct critical time scales over which the TEPIX has exhibited maximum
uncertainty.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:39:42 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Jafari",
"G. R.",
""
],
[
"Movahed",
"M. Sadegh",
""
],
[
"Noroozzadeh",
"P.",
""
],
[
"Bahraminasab",
"A.",
""
],
[
"Sahimi",
"Muhammad",
""
],
[
"Ghasemi",
"F.",
""
],
[
"Tabar",
"M. Reza Rahimi",
""
]
] |
0706.1461 | Fabio Biancalana | Fabio Biancalana, Andreas Amann, Eoin P. O'Reilly | Gap solitons in spatiotemporal photonic crystals | 3 figures, submitted | null | 10.1103/PhysRevA.77.011801 | null | physics.optics | null | We generalize the concept of nonlinear periodic structures to systems that
show arbitrary spacetime variations of the refractive index. Nonlinear pulse
propagation through these spatiotemporal photonic crystals can be described,
for shallow nonstationary gratings, by coupled mode equations which are a
generalization of the traditional equations used for stationary photonic
crystals. Novel gap soliton solutions are found by solving a modified massive
Thirring model. They represent the missing link between the gap solitons in
static photonic crystals and resonance solitons found in dynamic gratings.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 12:54:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Biancalana",
"Fabio",
""
],
[
"Amann",
"Andreas",
""
],
[
"O'Reilly",
"Eoin P.",
""
]
] |
0706.1462 | Werner Rodejohann | Srubabati Goswami, Werner Rodejohann | MiniBooNE Results and Neutrino Schemes with 2 sterile Neutrinos:
Possible Mass Orderings and Observables related to Neutrino Masses | 33 pages, 8 figures. Comments added, to appear in JHEP | JHEP0710:073,2007 | 10.1088/1126-6708/2007/10/073 | null | hep-ph astro-ph hep-ex | null | The MiniBooNE and LSND experiments are compatible with each other when two
sterile neutrinos are added to the three active ones. In this case there are
eight possible mass orderings. In two of them both sterile neutrinos are
heavier than the three active ones. In the next two scenarios both sterile
neutrinos are lighter than the three active ones. The remaining four scenarios
have one sterile neutrino heavier and another lighter than the three active
ones. We analyze all scenarios with respect to their predictions for
mass-related observables. These are the sum of neutrino masses as constrained
by cosmological observations, the kinematic mass parameter as measurable in the
KATRIN experiment, and the effective mass governing neutrinoless double beta
decay. It is investigated how these non-oscillation probes can distinguish
between the eight scenarios. Six of the eight possible mass orderings predict
positive signals in the KATRIN and future neutrinoless double beta decay
experiments. We also remark on scenarios with three sterile neutrinos. In
addition we make some comments on the possibility of using decays of high
energy astrophysical neutrinos to discriminate between the mass orderings in
presence of two sterile neutrinos.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:16:31 GMT"
},
{
"version": "v2",
"created": "Mon, 8 Oct 2007 08:58:09 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Goswami",
"Srubabati",
""
],
[
"Rodejohann",
"Werner",
""
]
] |
0706.1463 | Niko Johannsen | N. Johannsen, Th. Wolf, A. V. Sologubenko, T. Lorenz, A. Freimuth, J.
A. Mydosh | Nernst Effect in NdBa_2[Cu_{1-y}Ni_y]_3O_{7-\delta} | null | Phys. Rev. B 76, 020512(R) (2007) | 10.1103/PhysRevB.76.020512 | null | cond-mat.supr-con cond-mat.str-el | null | In NdBa_2[Cu_{1-y}Ni_y]_3O_{7-\delta}, magnetic Ni-impurities suppress Tc but
at the same time the pseudogap is strongly enhanced. This unique feature makes
it an ideal system to study possible relations between the anomalous Nernst
effect, superconductivity and the pseudogap. We present Nernst effect
measurements on a series of optimally doped (O_7) and underdoped (O_{6.8})
samples with Ni contents ranging from y=0 to 0.12. In all samples an onset of
the Nernst signal is found at T^\nu > Tc. For the optimally doped samples T^\nu
and Tc decrease simultaneously with increasing Ni content. The underdoped
samples show a different behavior, i.e. the onset of the Nernst signal is
hardly affected by increasing the Ni content from y=0 to 0.03. Irrespective of
the oxygen content, T^\nu clearly does not track the enhanced pseudogap
temperature T*.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:15:15 GMT"
}
] | 2007-09-10T00:00:00 | [
[
"Johannsen",
"N.",
""
],
[
"Wolf",
"Th.",
""
],
[
"Sologubenko",
"A. V.",
""
],
[
"Lorenz",
"T.",
""
],
[
"Freimuth",
"A.",
""
],
[
"Mydosh",
"J. A.",
""
]
] |
0706.1464 | Edward Cackett | E. M. Cackett (Univ. of Michigan), K. Horne (Univ. of St Andrews), H.
Winkler (Univ. of Johannesburg) | Testing thermal reprocessing in AGN accretion discs | 16 pages, 13 figures, accepted for publication in MNRAS | null | 10.1111/j.1365-2966.2007.12098.x | null | astro-ph | null | The thermal reprocessing hypothesis in AGN, where EUV/X-ray photons are
reprocessed by the accretion disc into optical/UV photons, predicts
wavelength-dependent time delays between the optical continuum at different
wavelengths. Recent photometric monitoring by Sergeev et al. has shown that the
time-delay is observed in 14 AGN, and generally seen to increase with
increasing wavelength, as predicted in the reprocessing scenario. We fit the
observed time delays and optical spectral energy distribution using a disc
reprocessing model. The model delivers estimates for the nuclear reddening, the
product of black hole mass times accretion rate, and the distance to each
object. However, the distances at face value give H_0 = 44 +/- 5 km/s/Mpc - a
factor of 1.6 smaller than generally accepted. We discuss the implications of
this on the reprocessing model.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:27:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Cackett",
"E. M.",
"",
"Univ. of Michigan"
],
[
"Horne",
"K.",
"",
"Univ. of St Andrews"
],
[
"Winkler",
"H.",
"",
"Univ. of Johannesburg"
]
] |
0706.1465 | Tun Wang | T. Wang J. Javanainen S. F. Yelin | Supercurrents in an atom-molecule gas in an optical ring lattice | 5 pages, 4 figures, submitted to PRA | null | null | null | quant-ph | null | Atom and molecule currents in a Fermi gas in the neighborhood of a Feshbach
resonance are studied in a one-dimensional optical ring lattice by directly
diagonalizing small models. A rotational analogy of flux quantization is used
to show that fraction of the current is carried by particles with twice the
mass of an atom, which suggests pairing and superfluidity.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:22:48 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Yelin",
"T. Wang J. Javanainen S. F.",
""
]
] |
0706.1466 | Fabrizio M. E. Catanese | Ingrid Bauer and Fabrizio Catanese (Universitaet Bayreuth), Fritz
Grunewald (Universitaet Duesseldorf) | The absolute Galois group acts faithfully on the connected components of
the moduli space of surfaces of general type | 13 pages and 2 figures | null | null | null | math.AG math.NT | null | We show that the Galois group $Gal(\bar{\Q} /\Q)$ operates faithfully on the
set of connected components of the moduli spaces of surfaces of general type,
and also that for each element $\sigma \in Gal(\bar{\Q} /\Q)$ different from
the identity and from complex conjugation, there is a surface of general type
such that $X$ and the Galois conjugate variety $X^{\sigma}$ have nonisomorphic
fundamental groups. The result was announced by the second author at the
Alghero Conference 'Topology of algebraic varieties' in september 2006. Before
the present paper was actually written, we received a very interesting preprint
by Robert Easton and Ravi Vakil (\cite{e-v}), where it is proven, with a
completely different type of examples, that the Galois group $Gal(\bar{\Q}
/\Q)$ operates faithfully on the set of irreducible components of the moduli
spaces of surfaces of general type. We also give other simpler examples of
surfaces with nonisomorphic fundamental groups which are Galois conjugate,
hence have isomorphic algebraic fundamental groups.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:29:24 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Bauer",
"Ingrid",
"",
"Universitaet Bayreuth"
],
[
"Catanese",
"Fabrizio",
"",
"Universitaet Bayreuth"
],
[
"Grunewald",
"Fritz",
"",
"Universitaet Duesseldorf"
]
] |
0706.1467 | Caroline Herzenberg | C. L. Herzenberg | The Quantum-Classical Transition and Wave Packet Dispersion | 10 pages, 0 figures | null | null | null | physics.gen-ph | null | Two recent studies have presented new information relevant to the transition
from quantum behavior to classical behavior, and related this to parameters
characterizing the universe as a whole. The present study based on a separate
approach has developed similar results that appear to substantiate aspects of
earlier work and also to introduce further new ideas.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:49:08 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Herzenberg",
"C. L.",
""
]
] |
0706.1468 | Francisco Rivadulla Fernandez | S. Blanco-Canosa, F. Rivadulla, V. Pardo, D. Baldomir, J.-S. Zhou, M.
Garcia-Hernandez, M. A. Lopez-Quintela, J. Rivas, J. B. Goodenough | Enhanced Pressure Dependence of Magnetic Exchange in A2+[V2]O4 Spinels
Approaching the Itinerant Electron Limit | null | null | 10.1103/PhysRevLett.99.187201 | null | cond-mat.str-el | null | We report a systematic enhancement of the pressure dependence of TN in
A2+[V2]O4 spinels as the V-V separation approaches the critical separation for
a transition to itinerant-electron behavior. An intermediate phase between
localized and itinerant electron behavior is identified in Zn[V2]O4 and
Mg[V2]O4 exhibiting mobile holes as large polarons. In Zn[V2]O4, cooperative
ordering of V-V pairs below a Ts=TN does not totally suppress the V3+-ion spins
at ambient pressure, but makes TN to decrease with pressure. Our results
demonstrate that Zn[V2]O4 and Mg[V2]O4 are less localized than previously
thought.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:36:10 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Blanco-Canosa",
"S.",
""
],
[
"Rivadulla",
"F.",
""
],
[
"Pardo",
"V.",
""
],
[
"Baldomir",
"D.",
""
],
[
"Zhou",
"J. -S.",
""
],
[
"Garcia-Hernandez",
"M.",
""
],
[
"Lopez-Quintela",
"M. A.",
""
],
[
"Rivas",
"J.",
""
],
[
"Goodenough",
"J. B.",
""
]
] |
0706.1469 | Stefano Bellucci | S. Bellucci, S. Krivonos, V. Ohanyan | N=4 Supersymmetric MICZ-Kepler systems on S3 | 8 pages, PACS: 11.30.Pb, 03.65.-w; corrected a misprint in (3.12),
added the last sentence on page 3, added the paragraph after (3.7), added the
sentence after (4.5) | Phys.Rev.D76:105023,2007 | 10.1103/PhysRevD.76.105023 | null | hep-th | null | Proceeding from the superfield action for $N=4, d=1$ nonlinear
supermultiplet, equipped with the most general potential term, we find the
action describing a charged particle on the sphere $S^3$ in the field of $n$
fixed Dirac dyons. We construct the supercharges and Hamiltonian and analyze
some particulary interesting potentials corresponding to the N=4 supersymmetric
extension of the integrable one- and two-center
McIntosh--Cisneros--Zwanziger--Kepler (MICZ-Kepler) systems on $S^3$.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:39:14 GMT"
},
{
"version": "v2",
"created": "Wed, 17 Oct 2007 13:17:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Bellucci",
"S.",
""
],
[
"Krivonos",
"S.",
""
],
[
"Ohanyan",
"V.",
""
]
] |
0706.1470 | Tun Wang | T. Wang and S. F. Yelin | Fast mode of rotating atoms in one-dimensional lattice rings | 4 pages, 5 figures | null | 10.1103/PhysRevA.76.033619 | null | quant-ph | null | We study the rotation of atoms in one-dimensional lattice rings. In
particular, the "fast mode", where the ground state atoms rotate faster than
the stirring rotating the atoms, is studied both analytically and numerically.
The conditions for the transition to the fast mode are found to be very
different from that in continuum rings. We argue that these transition
frequencies remain unchanged for bosonic condensates described in a mean field.
We show that Fermionic interaction and filling factor have a significant effect
on the transition to the fast mode, and Pauli principle may suppress it
altogether.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:40:53 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Wang",
"T.",
""
],
[
"Yelin",
"S. F.",
""
]
] |
0706.1471 | Hui Li | Hui Li | Singular unitarity in "quantization commutes with reduction" | 28 pages | null | 10.1016/j.geomphys.2008.01.006 | null | math.SG | null | Let $M$ be a connected compact quantizable K\"ahler manifold equipped with a
Hamiltonian action of a connected compact Lie group $G$. Let
$M//G=\phi^{-1}(0)/G=M_0$ be the symplectic quotient at value 0 of the moment
map $\phi$. The space $M_0$ may in general not be smooth. It is known that, as
vector spaces, there is a natural isomorphism between the quantum Hilbert space
over $M_0$ and the $G$-invariant subspace of the quantum Hilbert space over
$M$. In this paper, without any regularity assumption on the quotient $M_0$, we
discuss the relation between the inner products of these two quantum Hilbert
spaces under the above natural isomorphism; we establish asymptotic unitarity
to leading order in Planck's constant of a modified map of the above
isomorphism under a ``metaplectic correction'' of the two quantum Hilbert
spaces.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:43:58 GMT"
},
{
"version": "v2",
"created": "Tue, 24 Jul 2007 13:34:40 GMT"
},
{
"version": "v3",
"created": "Wed, 9 Jan 2008 15:35:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Li",
"Hui",
""
]
] |
0706.1472 | Michel Enock | Michel Enock | On Lesieur's Measured Quantum Groupoids | null | null | null | null | math.OA | null | In his thesis ([L1]), which is published in an expended and revised version
([L2]), Franck Lesieur had introduced a notion of measured quantum groupoid, in
the setting of von Neumann algebras, using intensively the notion of
pseudo-multiplicative unitary, which had been introduced in a previous article
of the author, in collaboration with Jean-Michel Vallin [EV]. In [L2], the
axioms given are very complicated and are here simplified.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:44:54 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Enock",
"Michel",
""
]
] |
0706.1473 | Artur Sergyeyev | Artur Sergyeyev and Maciej Blaszak | Generalized St\"ackel Transform and Reciprocal Transformations for
Finite-Dimensional Integrable Systems | 21 pages, LaTeX 2e, no figures; major revision; Propositions 2 and 7
and several new references added | J.Phys.A41:105205,2008 | 10.1088/1751-8113/41/10/105205 | null | nlin.SI hep-th math-ph math.MP | null | We present a multiparameter generalization of the St\"ackel transform (the
latter is also known as the coupling-constant metamorphosis) and show that
under certain conditions this generalized St\"ackel transform preserves the
Liouville integrability, noncommutative integrability and superintegrability.
The corresponding transformation for the equations of motion proves to be
nothing but a reciprocal transformation of a special form, and we investigate
the properties of this reciprocal transformation.
Finally, we show that the Hamiltonians of the systems possessing separation
curves of apparently very different form can be related through a suitably
chosen generalized St\"ackel transform.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:03:12 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Jun 2007 21:21:25 GMT"
},
{
"version": "v3",
"created": "Wed, 26 Sep 2007 17:22:27 GMT"
},
{
"version": "v4",
"created": "Thu, 20 Dec 2007 23:19:52 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Sergyeyev",
"Artur",
""
],
[
"Blaszak",
"Maciej",
""
]
] |
0706.1474 | Sven Menke | Sven Menke | Determination of the Jet Energy Scale | 5 pages, 5 figures, talk given at HCP 2007 | Nucl.Phys.Proc.Suppl.177-178:195-199,2008 | 10.1016/j.nuclphysbps.2007.11.109 | MPP-2007-70 | hep-ex | null | The uncertainty in jet energy scale is one of the dominating systematic
errors for many measurements at hadron colliders - most notably for the
measurement of the top-quark-mass, inclusive jet cross section measurements and
last but not least for events with large missing transverse energy as expected
in searches beyond the standard model. This talk will review the approaches
taken at Tevatron towards controlling the jet energy scale and discuss
prospects for the LHC experiments.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:39:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Menke",
"Sven",
""
]
] |
0706.1475 | Raquel Caseiro | Raquel Caseiro and Joana M. Nunes da Costa | Jacobi-Nijenhuis algebroids and their modular classes | null | null | 10.1088/1751-8113/40/44/012 | null | math.DG math.SG | null | Jacobi-Nijenhuis algebroids are defined as a natural generalization of
Poisson-Nijenhuis algebroids, in the case where there exists a Nijenhuis
operator on a Jacobi algebroid which is compatible with it. We study modular
classes of Jacobi and Jacobi-Nijenhuis algebroids.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:53:40 GMT"
},
{
"version": "v2",
"created": "Wed, 26 Sep 2007 16:23:58 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Caseiro",
"Raquel",
""
],
[
"da Costa",
"Joana M. Nunes",
""
]
] |
0706.1476 | Pedro Sacramento | P. D. Sacramento, P. Nogueira, V. R. Vieira and V. K. Dugaev | Entanglement signatures of the quantum phase transition induced by a
magnetic impurity in a superconductor | 14 pages, 12 figures | null | 10.1103/PhysRevB.76.184517 | null | cond-mat.supr-con | null | The insertion of a magnetic impurity in a superconductor induces a first
order quantum phase transition as the coupling to the electronic spin density
increases. As the transition is crossed, a discontinuity is exhibited by
various quantities, like the total spin density, the total gap function and the
gap function at the impurity location. The location of other quantum phase
transitions have been detected by singularities in entanglement measures of the
system. In this work we show that the single-site and two-site von Neumann
entropies, the mutual information and the Meyer-Wallach measure show
discontinuities at the quantum phase transition. The negativity is less
sensitive to the transition. We study in detail these quantities as a function
of spin coupling and distance from the impurity center.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:54:22 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Sacramento",
"P. D.",
""
],
[
"Nogueira",
"P.",
""
],
[
"Vieira",
"V. R.",
""
],
[
"Dugaev",
"V. K.",
""
]
] |
0706.1477 | Sylvain Perifel | Pascal Koiran (LIP), Sylvain Perifel (LIP) | VPSPACE and a transfer theorem over the complex field | 14 pages | null | null | null | cs.CC | null | We extend the transfer theorem of [KP2007] to the complex field. That is, we
investigate the links between the class VPSPACE of families of polynomials and
the Blum-Shub-Smale model of computation over C. Roughly speaking, a family of
polynomials is in VPSPACE if its coefficients can be computed in polynomial
space. Our main result is that if (uniform, constant-free) VPSPACE families can
be evaluated efficiently then the class PAR of decision problems that can be
solved in parallel polynomial time over the complex field collapses to P. As a
result, one must first be able to show that there are VPSPACE families which
are hard to evaluate in order to separate P from NP over C, or even from PAR.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 13:59:31 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Koiran",
"Pascal",
"",
"LIP"
],
[
"Perifel",
"Sylvain",
"",
"LIP"
]
] |
0706.1478 | David Petrosyan | David Petrosyan and P. Lambropoulos | Coherent population transfer in a chain of tunnel coupled quantum dots | null | Opt. Commun. 264, 419 (2006) | 10.1016/j.optcom.2005.12.082 | null | quant-ph | null | We consider the dynamics of a single electron in a chain of tunnel coupled
quantum dots, exploring the formal analogies of this system with some of the
laser-driven multilevel atomic or molecular systems studied by Bruce W. Shore
and collaborators over the last 30 years. In particular, we describe two
regimes for achieving complete coherent transfer of population in such a
multistate system. In the first regime, by carefully arranging the coupling
strengths, the flow of population between the states of the system can be made
periodic in time. In the second regime, by employing a "counterintuitive"
sequence of couplings, the coherent population trapping eigenstate of the
system can be rotated from the initial to the final desired state, which is an
equivalent of the STIRAP technique for atoms or molecules. Our results may be
useful in future quantum computation schemes.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:04:55 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Petrosyan",
"David",
""
],
[
"Lambropoulos",
"P.",
""
]
] |
0706.1479 | H. Panagopoulos | Luigi Del Debbio (1), Haralambos Panagopoulos (2), Ettore Vicari (3)
((1) SUPA, School of Physics, Univ. of Edinburgh, (2) Department of Physics,
Univ. of Cyprus, (3) Department of Physics, Univ. of Pisa) | SU(N) gauge theories in the presence of a topological term | 18 pages, presentation at the HEP2007 Conference, Manchester, 7/2007.
A couple of references added | J.Phys.Conf.Ser.110:122005,2008 | 10.1088/1742-6596/110/12/122005 | null | hep-th hep-lat | null | We review recent results on the theta dependence of the ground-state energy
and spectrum of four-dimensional SU(N) gauge theories, where theta is the
coefficient of the CP-violating topological term F-Fdual in the Lagrangian. In
particular, we discuss the results obtained by Monte Carlo simulations of the
lattice formulation of QCD, which allow the investigation of theta dependence
around theta=0 by determining the moments of the topological charge
distribution, and their correlations with other observables. The results for
N=3 and larger values of N support the scenario obtained by general large-N
scaling arguments.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:05:48 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 12:32:28 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Del Debbio",
"Luigi",
""
],
[
"Panagopoulos",
"Haralambos",
""
],
[
"Vicari",
"Ettore",
""
]
] |
0706.1480 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola | Some necessary and sufficient conditions for parastrophic invariance of
the associative law in quasigroups | 11 pages | Fasciculi Mathematici, Vol. 40 (2008), 25-35 | null | null | math.GM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Every quasigroup $(S,\cdot)$ belongs to a set of 6 quasigroups, called
parastrophes denoted by $(S,\pi_i)$, $i\in \{1,2,3,4,5,6\}$. It is shown that
isotopy-isomorphy is a necessary and sufficient condition for any two distinct
quasigroups $(S,\pi_i)$ and $(S,\pi_j)$, $i,j\in \{1,2,3,4,5,6\}$ to be
parastrophic invariant relative to the associative law. In addition, a
necessary and sufficient condition for any two distinct quasigroups $(S,\pi_i)$
and $(S,\pi_j)$, $i,j\in \{1,2,3,4,5,6\}$ to be parastrophic invariance under
the associative law is either if the $\pi_i$-parastrophe of $H$ is equivalent
to the $\pi_i$-parastrophe of the holomorph of the $\pi_i$-parastrophe of $S$
or if the $\pi_i$-parastrophe of $H$ is equivalent to the $\pi_k$-parastrophe
of the $\pi_i$-parastrophe of the holomorph of the $\pi_i$-parastrophe of $S$,
for a particular $k\in \{1,2,3,4,5,6\}$.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:07:09 GMT"
},
{
"version": "v2",
"created": "Thu, 5 Jun 2008 09:34:31 GMT"
},
{
"version": "v3",
"created": "Tue, 10 Mar 2009 17:12:43 GMT"
}
] | 2010-03-09T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
]
] |
0706.1481 | Jaiyeola Temitope Gbolahan | Temitope Gbolahan Jaiyeola and John Olushola Adeniran | Weak Inverse Property Loops and Some Isotopy-Isomorphy Properties | 8 pages, submitted for publication | Acta Universitatis Apulensis Mathematics-Informatics, Vol. 18
(2009), 19-33. | null | null | math.GR | null | Two distinct isotopy-isomorphy conditions, different from those of J. M.
Osborn and Wilson's condition, for a weak inverse property loop(WIPL) are
shown. Only one of them characterizes isotopy-isomorphy in WIPLs while the
other is just a sufficient condition for isotopy-isomorphy. Under the
sufficient condition called the ${\cal T}$ condition, Artzy's result that
isotopic cross inverse property loops(CIPL) are isomorphic is proved for WIP
loops.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:10:07 GMT"
}
] | 2010-03-09T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
],
[
"Adeniran",
"John Olushola",
""
]
] |
0706.1482 | Temitope Jaiyeola Gbolahan | Temitope Gbolahan Jaiyeola | On a Pair of Universal Weak Inverse Property Loops | 14 pages. | NUMTA Bulletin, Vol. 1(2009), 22-40. | null | null | math.GM | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A new condition called ${\cal T}$ condition is introduced for the first time
and used to study a pair of isotopic loops. Under this condition, a loop in the
pair is a WIPL if and only if the other loop is a WIPL. Furthermore, such WIPLs
are isomorphic. The translation elements $f$ and $g$ of a CIPL with the ${\cal
T}$ condition(such that its $f,g$-isotope is an automorphic inverse property
loop) are found to be alternative, flexible, centrum and equal elements. A
necessary and sufficient condition for a pair WIPLs with a weak ${\cal T}$
condition to be isomorphic is shown. A CIPL and an isomorph are observed to
have this weak ${\cal T}$ condition.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:12:27 GMT"
},
{
"version": "v2",
"created": "Wed, 10 Mar 2010 13:05:05 GMT"
}
] | 2010-03-11T00:00:00 | [
[
"Jaiyeola",
"Temitope Gbolahan",
""
]
] |
0706.1483 | Dorin Ervin Dutkay | Dorin Ervin Dutkay, Palle E.T. Jorgensen, and Gabriel Picioroaga | Unitary Representations of Wavelet Groups and Encoding of Iterated
Function Systems in Solenoids | null | null | null | null | math.NT math.FA | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | For points in $d$ real dimensions, we introduce a geometry for general digit
sets. We introduce a positional number system where the basis for our
representation is a fixed $d$ by $d$ matrix over $\bz$. Our starting point is a
given pair $(A, \mathcal D)$ with the matrix $A$ assumed expansive, and
$\mathcal D$ a chosen complete digit set, i.e., in bijective correspondence
with the points in $\bz^d/A^T\bz^d$. We give an explicit geometric
representation and encoding with infinite words in letters from $\mathcal D$.
We show that the attractor $X(A^T,\mathcal D)$ for an affine Iterated Function
System (IFS) based on $(A,\mathcal D)$ is a set of fractions for our digital
representation of points in $\br^d$. Moreover our positional "number
representation" is spelled out in the form of an explicit IFS-encoding of a
compact solenoid $\sa$ associated with the pair $(A,\mathcal D)$. The intricate
part (Theorem \ref{thenccycl}) is played by the cycles in $\bz^d$ for the
initial $(A,\mathcal D)$-IFS. Using these cycles we are able to write down
formulas for the two maps which do the encoding as well as the decoding in our
positional $\mathcal D$-representation.
We show how some wavelet representations can be realized on the solenoid, and
on symbolic spaces.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:27:29 GMT"
},
{
"version": "v2",
"created": "Fri, 6 Jul 2007 00:11:19 GMT"
},
{
"version": "v3",
"created": "Tue, 7 Oct 2008 22:33:04 GMT"
}
] | 2008-10-08T00:00:00 | [
[
"Dutkay",
"Dorin Ervin",
""
],
[
"Jorgensen",
"Palle E. T.",
""
],
[
"Picioroaga",
"Gabriel",
""
]
] |
0706.1484 | Demetrio Stojanoff | Mariano A. Ruiz and Demetrio Stojanoff | Frames of subspaces and operators | 21 pages, LaTeX; added references and comments about fusion frames | null | null | null | math.FA math.OA | null | We study the relationship between operators, orthonormal basis of subspaces
and frames of subspaces (also called fusion frames) for a separable Hilbert
space $\mathcal{H}$. We get sufficient conditions on an orthonormal basis of
subspaces $\mathcal{E} = \{E_i \}_{i\in I}$ of a Hilbert space $\mathcal{K}$
and a surjective $T\in L(\mathcal{K}, \mathcal{H})$ in order that
$\{T(E_i)\}_{i\in I}$ is a frame of subspaces with respect to a computable
sequence of weights. We also obtain generalizations of results in [J. A.
Antezana, G. Corach, M. Ruiz and D. Stojanoff, Oblique projections and frames.
Proc. Amer. Math. Soc. 134 (2006), 1031-1037], which related frames of
subspaces (including the computation of their weights) and oblique projections.
The notion of refinament of a fusion frame is defined and used to obtain
results about the excess of such frames. We study the set of admissible weights
for a generating sequence of subspaces. Several examples are given.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:30:40 GMT"
},
{
"version": "v2",
"created": "Fri, 15 Jun 2007 18:42:11 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Ruiz",
"Mariano A.",
""
],
[
"Stojanoff",
"Demetrio",
""
]
] |
0706.1485 | Claudia Kirch | Marie Huskova, Claudia Kirch | Bootstrapping confidence intervals for the change-point of time series | 25 pages, 25 figures | Journal of Time Series Analysis. 29:947-972, 2008 | 10.1111/j.1467-9892.2008.00589.x | null | math.ST stat.TH | null | We study an AMOC time series model with an abrupt change in the mean and
dependent errors that fulfill certain mixing conditions. We obtain confidence
intervals for the unknown change-point via bootstrapping methods.
Precisely we use a block bootstrap of the estimated centered error sequence.
Then we reconstruct a sequence with a change in the mean using the same
estimators as before. The difference between the change-point estimator of the
resampled sequence and the one for the original sequence can be use as an
approximation of the difference between the real change-point and its
estimator. This enables us to construct confidence intervals using the
empirical distribution of the resampled time series.
A simulation study shows that the resampled confidence intervals are usually
closer to their target levels and at the same time smaller than the asymptotic
intervals.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:32:13 GMT"
}
] | 2008-10-30T00:00:00 | [
[
"Huskova",
"Marie",
""
],
[
"Kirch",
"Claudia",
""
]
] |
0706.1486 | Lewin Mathieu | Christian Hainzl, Mathieu Lewin, Eric Sere and Jan Philip Solovej | A Minimization Method for Relativistic Electrons in a Mean-Field
Approximation of Quantum Electrodynamics | 18 pages, 3 figures | null | 10.1103/PhysRevA.76.052104 | null | physics.atom-ph math-ph math.MP | null | We study a mean-field relativistic model which is able to describe both the
behavior of finitely many spin-1/2 particles like electrons and of the Dirac
sea which is self-consistently polarized in the presence of the real particles.
The model is derived from the QED Hamiltonian in Coulomb gauge neglecting the
photon field. All our results are non-perturbative and mathematically rigorous.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:34:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Hainzl",
"Christian",
""
],
[
"Lewin",
"Mathieu",
""
],
[
"Sere",
"Eric",
""
],
[
"Solovej",
"Jan Philip",
""
]
] |
0706.1487 | Piet Brouwer | Piet W. Brouwer | Semiclassical theory of the Ehrenfest-time dependence of quantum
transport | 22 pages, 9 figures | null | 10.1103/PhysRevB.76.165313 | null | cond-mat.mes-hall | null | In ballistic conductors, there is a low-time threshold for the appearance of
quantum effects in transport coefficients. This low-time threshold is the
Ehrenfest time. Most previous studies of the Ehrenfest-time dependence of
quantum transport assumed ergodic electron dynamics, so that they could be
applied to ballistic quantum dots only. In this article we present a theory of
the Ehrenfest-time dependence of three signatures of quantum transport - the
Fano factor for the shot noise power, the weak localization correction to the
conductance, and the conductance fluctuations - for arbitrary ballistic
conductors.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 14:51:06 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Brouwer",
"Piet W.",
""
]
] |
0706.1488 | Rene Cote | R. Cote, M.-A. Lemonde, C. B. Doiron and A. M. Ettouhami | Dynamical matrix of two-dimensional electron crystals | Revised version published in Phys. Rev. B. 12 pages with 11
postscripts figures | R. Cote, M.-A. Lemonde, C. B. Doiron, and A. M. Ettouhami, Phys.
Rev. B 77, 115303 (2008) | 10.1103/PhysRevB.77.115303 | null | cond-mat.mes-hall | null | In a quantizing magnetic field, the two-dimensional electron (2DEG) gas has a
rich phase diagram with broken translational symmetry phases such as Wigner,
bubble, and stripe crystals. In this paper, we derive a method to get the
dynamical matrix of these crystals from a calculation of the density response
function performed in the Generalized Random Phase Approximation (GRPA). We
discuss the validity of our method by comparing the dynamical matrix calculated
from the GRPA with that obtained from standard elasticity theory with the
elastic coefficients obtained from a calculation of the deformation energy of
the crystal.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:02:10 GMT"
},
{
"version": "v2",
"created": "Wed, 5 Mar 2008 01:47:19 GMT"
}
] | 2008-03-05T00:00:00 | [
[
"Cote",
"R.",
""
],
[
"Lemonde",
"M. -A.",
""
],
[
"Doiron",
"C. B.",
""
],
[
"Ettouhami",
"A. M.",
""
]
] |
0706.1489 | Francois Vigneron | Lorenzo Brandolese (1) and Francois Vigneron (2) ((1) Universit\'e de
Lyon 1, (2) Ecole polytechnique - CMLS) | New Asymptotic Profiles of Nonstationnary Solutions of the Navier-Stokes
System | 26 pages, article to appear in Journal de Math\'ematiques Pures et
Appliqu\'ees | null | null | null | math.AP math-ph math.MP | null | We show that solutions $u(x,t)$ of the non-stationnary incompressible
Navier--Stokes system in $\R^d$ ($d\geq2$) starting from mild decaying data $a$
behave as $|x|\to\infty$ as a potential field: u(x,t) = e^{t\Delta}a(x) +
\gamma_d\nabla_x(\sum_{h,k} \frac{\delta_{h,k}|x|^2 - d x_h x_k}{d|x|^{d+2}}
K_{h,k}(t))+\mathfrak{o}(\frac{1}{|x|^{d+1}}) where $\gamma_d$ is a constant
and $K_{h,k}=\int_0^t(u_h| u_k)_{L^2}$ is the energy matrix of the flow. We
deduce that, for well localized data, and for small $t$ and large enough $|x|$,
c t |x|^{-(d+1)} \le |u(x,t)|\le c' t |x|^{-(d+1)}, where the lower bound holds
on the complementary of a set of directions, of arbitrary small measure on
$\mathbb{S}^{d-1}$. We also obtain new lower bounds for the large time decay of
the weighted-$L^p$ norms, extending previous results of Schonbek, Miyakawa, Bae
and Jin.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:03:13 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Brandolese",
"Lorenzo",
""
],
[
"Vigneron",
"Francois",
""
]
] |
0706.1490 | Stephen Barr | S.M. Barr | Radiative Fermion Mass Hierarchy in a Non-supersymmetric Unified Theory | 14 pages | Phys.Rev.D76:105024,2007 | 10.1103/PhysRevD.76.105024 | null | hep-ph | null | In non-supersymmetric grand unified models a ``radiative fermion mass
hierarchy" can be achieved in which the spectrum of quark and lepton masses is
determined entirely by physics at the unification scale, with many relations
following from the unified gauge symmetry, and with the masses of the lightest
family arising from loops. A simple, realistic, and predictive model of this
kind is presented. A "doubly lopsided" structure, known to lead to bilarge
neutrino mixing, plays a crucial role in the radiative hierarchy.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:17:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Barr",
"S. M.",
""
]
] |
0706.1491 | Carla Bleve | Carla Bleve (for the Pierre Auger Collaboration) | Weather induced effects on extensive air showers observed with the
surface detector of the Pierre Auger Observatory | Contribution to the 30th International Cosmic Ray Conference, Merida,
Mexico, July 2007 | null | null | null | astro-ph | null | The rate of events measured with the surface detector of the Pierre Auger
Observatory is found to be modulated by the weather conditions. This effect is
due to the increasing amount of matter traversed by the shower as the ground
pressure increases and to the inverse proportionality of the Moliere radius to
the air density near ground. Air-shower simulations with different realistic
profiles of the atmosphere support this interpretation of the observed effects.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:24:14 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Bleve",
"Carla",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.1492 | Adrien Lerbret | A. Lerbret, P. Bordat, F. Affouard, A. Hedoux, Y. Guinet, M. Descamps | How do trehalose, maltose and sucrose influence some structural and
dynamical properties of lysozyme ? An insight from Molecular Dynamics
simulations | null | null | null | null | physics.chem-ph cond-mat.soft q-bio.BM | null | The influence of three well-known disaccharides, namely trehalose, maltose
and sucrose, on some structural and dynamical properties of lysozyme has been
investigated by means of molecular dynamics computer simulations in the 37-60
wt % concentration range. The effects of sugars on the protein conformation are
found relatively weak, in agreement with the preferential hydration of
lysozyme. Conversely, sugars seem to increase significantly the relaxation
times of the protein. These effects are shown to be correlated to the
fractional solvent accessibilities of lysozyme residues and further support the
slaving of protein dynamics. Moreover, a significant increase in the relaxation
times of lysozyme, sugars and water molecules is observed within the studied
concentration range and may result from the percolation of the hydrogen-bond
network of sugar molecules. This percolation appears to be of primary
importance to explain the influence of sugars on the dynamical properties of
lysozyme and water.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:43:56 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Lerbret",
"A.",
""
],
[
"Bordat",
"P.",
""
],
[
"Affouard",
"F.",
""
],
[
"Hedoux",
"A.",
""
],
[
"Guinet",
"Y.",
""
],
[
"Descamps",
"M.",
""
]
] |
0706.1493 | Stephanie Lo | S. Lo (1), A. V. Korol (1 and 2) and A. V. Solov'yov (1) ((1)
Frankfurt Institute of Advanced Studies, Germany, (2) St. Petersburg State
Maritime Technical University, Russia) | Dynamical Screening of Atom Confined by Finite-Width Fullerene | 10 pages, 4 figures correction of figure 2 and equation 16 | J. Phys. B: At. Mol. Opt. Phys. 40 (2007) 3973-3981 | 10.1088/0953-4075/40/19/014 | null | physics.atm-clus | null | This is an investigation on the dynamical screening of an atom confined
within a fullerene of finite width. The two surfaces of the fullerene lead to
the presence of two surface plasmon eigenmodes. It is shown that, in the
vicinity of these two eigenfrequencies, there is a large enhancement of the
confined atom's photoabsorption rate.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:00:31 GMT"
},
{
"version": "v2",
"created": "Thu, 6 Sep 2007 16:00:43 GMT"
},
{
"version": "v3",
"created": "Thu, 20 Sep 2007 21:44:26 GMT"
}
] | 2008-11-10T00:00:00 | [
[
"Lo",
"S.",
"",
"1 and 2"
],
[
"Korol",
"A. V.",
"",
"1 and 2"
],
[
"Solov'yov",
"A. V.",
""
]
] |
0706.1494 | Arul Lakshminarayan | Steven Tomsovic, Arul Lakshminarayan | Fluctuations of finite-time stability exponents in the standard map and
the detection of small islands | 31 pages, 11 figs | Phys. Rev. E 82, 046223 (2010) | 10.1103/PhysRevE.76.036207 | null | nlin.CD | null | Some statistical properties of finite-time stability exponents in the
standard map can be estimated analytically. The mean exponent averaged over the
entire phase space behaves quite differently from all the other cumulants.
Whereas the mean carries information about the strength of the interaction, and
only indirect information about dynamical correlations, the higher cumulants
carry information about dynamical correlations and essentially no information
about the interaction strength. In particular, the variance and higher
cumulants of the exponent are very sensitive to dynamical correlations and
easily detect the presence of very small islands of regular motion via their
anomalous time-scalings. The average of the stability matrix' inverse trace is
even more sensitive to the presence of small islands and has a seemingly
fractal behavior in the standard map parameter. The usual accelerator modes and
the small islands created through double saddle node bifurcations, which come
halfway between the positions in interaction strength of the usual accelerator
modes, are clearly visible in the variance, whose time scaling is capable of
detecting the presence of islands as small as 0.01% of the phase space. We
study these quantities with a local approximation to the trace of the stability
matrix which significantly simplifies the numerical calculations as well as
allows for generalization of these methods to higher dimensions. We also
discuss the nature of this local approximation in some detail.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:37:36 GMT"
}
] | 2011-08-02T00:00:00 | [
[
"Tomsovic",
"Steven",
""
],
[
"Lakshminarayan",
"Arul",
""
]
] |
0706.1495 | Michael Unger | Michael Unger (for the Pierre Auger Collaboration) | Study of the Cosmic Ray Composition above 0.4 EeV using the Longitudinal
Profiles of Showers observed at the Pierre Auger Observatory | Contribution to the 30th International Cosmic Ray Conference, Merida
Mexico, July 2007 | null | null | null | astro-ph | null | The Pierre Auger Observatory has been collecting data in a stable manner
since January 2004. We present here a study of the cosmic ray composition using
events recorded in hybrid mode during the first years of data taking. These are
air showers observed by the fluorescence detector as well as the surface
detector, so the depth of shower maximum, Xmax, is measured directly. The
cosmic ray composition is studied in different energy ranges by comparing the
observed average Xmax with predictions from air shower simulations for
different nuclei. The change of <Xmax> with energy (elongation rate) is used to
derive estimates of the change in primary composition.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:39:47 GMT"
}
] | 2019-08-13T00:00:00 | [
[
"Unger",
"Michael",
"",
"for the Pierre Auger Collaboration"
]
] |
0706.1496 | Manuel Feito Guzm\'an | M. Feito and F. J. Cao | Time-Delayed Feedback control of a flashing ratchet | LaTeX, 11 pages, 13 figures. Material from arXiv:0706.4466 added.
Improved version to appear in Phys Rev E | Phys. Rev. E 76, 061113 (2007) | 10.1103/PhysRevE.76.061113 | null | cond-mat.stat-mech | null | Closed-loop or feedback control ratchets use information about the state of
the system to operate with the aim of maximizing the performance of the system.
In this paper we investigate the effects of a time delay in the feedback for a
protocol that performs an instantaneous maximization of the center-of-mass
velocity. For the one and the few particle cases the flux decreases with
increasing delay, as an effect of the decorrelation of the present state of the
system with the information that the controller uses, but the delayed
closed-loop protocol succeeds to perform better than its open-loop counterpart
provided the delays are smaller than the characteristic times of the Brownian
ratchet. For the many particle case, we also show that for small delays the
center-of-mass velocity decreases for increasing delays. However, for large
delays we find the surprising result that the presence of the delay can improve
the performance of the nondelayed feedback ratchet and the flux can attain the
maximum value obtained with the optimal periodic protocol. This phenomenon is
the result of the emergence of a dynamical regime where the presence of the
delayed feedback stabilizes one quasiperiodic solution or several
(multistability), which resemble the solutions obtained in the so-called
threshold protocol. Our analytical and numerical results point towards the
feasibility of an experimental implementation of a feedback controlled ratchet
that performs equal or better than its optimal open-loop version.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:39:56 GMT"
},
{
"version": "v2",
"created": "Mon, 5 Nov 2007 11:24:46 GMT"
}
] | 2007-12-13T00:00:00 | [
[
"Feito",
"M.",
""
],
[
"Cao",
"F. J.",
""
]
] |
0706.1497 | Harald A. Helfgott | Harald Andres Helfgott | Power-free values, repulsion between points, differing beliefs and the
existence of error | 8 pages; to appear in CRM conference proceedings | null | null | null | math.NT math.PR | null | Let f be a cubic polynomial. Then there are infinitely many primes p such
that f(p) is square-free.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:53:35 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Helfgott",
"Harald Andres",
""
]
] |
0706.1498 | Bruno Kahn | Luca Barbieri-Viale, Bruno Kahn (IMJ) | On the derived category of 1-motives, I | null | null | null | null | math.AG | null | We consider the category of Deligne 1-motives over a perfect field k of
exponential characteristic p and its derived category for a suitable exact
structure after inverting p. As a first result, we provide a fully faithful
embedding into an etale version of Voevodsky's triangulated category of
geometric motives. Our second main result is that this full embedding "almost"
has a left adjoint, that we call \LAlb. Applied to the motive of a variety we
thus get a bounded complex of 1-motives, that we compute fully for smooth
varieties and partly for singular varieties. As an application we give motivic
proofs of Roitman type theorems (in characteristic 0).
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:54:50 GMT"
}
] | 2009-09-29T00:00:00 | [
[
"Barbieri-Viale",
"Luca",
"",
"IMJ"
],
[
"Kahn",
"Bruno",
"",
"IMJ"
]
] |
0706.1499 | Wu Jing | Xuehan Cheng, Wu Jing | Elementary Maps on Triangular Algebras | 8 pages | null | null | null | math.RA math.OA | null | In this note we prove that elementary maps on triangular algebras are
automically additive.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:54:51 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 16:06:02 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Cheng",
"Xuehan",
""
],
[
"Jing",
"Wu",
""
]
] |
0706.1500 | Marilena Caramazza | M. Caramazza (1,2), E. Flaccomio (2), G. Micela (2), F. Reale (1,2),
S. J. Wolk (3), and E. D. Feigelson (4) ((1) Dipartimento di Scienze Fisiche
ed Astronomiche, Universita di Palermo,(2)INAF Osservatorio Astronomico di
Palermo,(3)Harvard-Smithsonian Center for Astrophysics,(4)Department of
Astronomy and Astrophysics, Pennsylvania State University) | X-ray Flares in Orion Low Mass Stars | null | null | 10.1051/0004-6361:20077195 | null | astro-ph | null | Context. X-ray flares are common phenomena in pre-main sequence stars. Their
analysis gives insights into the physics at work in young stellar coronae. The
Orion Nebula Cluster offers a unique opportunity to study large samples of
young low mass stars. This work is part of the Chandra Orion Ultradeep project
(COUP), an ~10 day long X-ray observation of the Orion Nebula Cluster (ONC).
Aims. Our main goal is to statistically characterize the flare-like variability
of 165 low mass (0.1-0.3 M_sun) ONC members in order to test and constrain the
physical scenario in which flares explain all the observed emission. Methods.
We adopt a maximum likelihood piece-wise representation of the observed X-ray
light curves and detect flares by taking into account both the amplitude and
time derivative of the count-rate. We then derive the frequency and energy
distribution of the flares. Results. The high energy tail of the energy
distribution of flares is well described by a power-law with index 2.2. We test
the hypothesis that light curves are built entirely by overlapping flares with
a single power law energy distribution. We constrain the parameters of this
simple model for every single light curve. The analysis of synthetic light
curves obtained from the model indicates a good agreement with the observed
data. Comparing low mass stars with stars in the mass interval (0.9-1.2M_sun),
we establish that, at ~1 Myr, low mass and solar mass stars of similar X-ray
luminosity have very similar flare frequencies. Conclusions. Our observational
results are consistent with the following model/scenario: the light curves are
entirely built by over- lapping flares with a power-law intensity distribution;
the intense flares are individually detected, while the weak ones merge and
form a pseudo-quiescent level, which we indicate as the characteristic level.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:58:50 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Caramazza",
"M.",
""
],
[
"Flaccomio",
"E.",
""
],
[
"Micela",
"G.",
""
],
[
"Reale",
"F.",
""
],
[
"Wolk",
"S. J.",
""
],
[
"Feigelson",
"E. D.",
""
]
] |
0706.1501 | Michael Unger | M. Unger, R. Engel, F. Sch\"ussler, R. Ulrich | Longitudinal Shower Profile Reconstruction from Fluorescence and
Cherenkov Light | Contribution to the 30th International Cosmic Ray Conference, Merida
Mexico, July 2007 | null | null | null | astro-ph | null | Traditionally, longitudinal shower profiles are reconstructed in fluorescence
light experiments by treating the Cherenkov light contribution as background.
Here we will argue that, due to universality of the energy spectra of electrons
and positrons, both fluorescence and Cherenkov light can be used simultaneously
as signal to infer the longitudinal shower development. We present a new
profile reconstruction method that is based on the analytic least-square
solution for the estimation of the shower profile from the observed light
signal and discuss the extrapolation of the profile with a Gaisser-Hillas
function.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:59:08 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Unger",
"M.",
""
],
[
"Engel",
"R.",
""
],
[
"Schüssler",
"F.",
""
],
[
"Ulrich",
"R.",
""
]
] |
0706.1502 | Wu Jing | Xuehan Cheng, Wu Jing | Additivity of Maps on Triangular Algebras | 11 pages | null | null | null | math.RA math.OA | null | We prove that every multiplicative bijective map, Jordan bijective map, and
Jordan triple bijective map from a triangular algebra onto any ring is
automatically additive.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 15:59:36 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Jun 2007 16:07:25 GMT"
}
] | 2007-06-13T00:00:00 | [
[
"Cheng",
"Xuehan",
""
],
[
"Jing",
"Wu",
""
]
] |
0706.1503 | Robert Dalang | Violetta Bernyk, Robert C. Dalang, Goran Peskir | The law of the supremum of a stable L\'{e}vy process with no negative
jumps | Published in at http://dx.doi.org/10.1214/07-AOP376 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org) | Annals of Probability 2008, Vol. 36, No. 5, 1777-1789 | 10.1214/07-AOP376 | IMS-AOP-AOP376 | math.PR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Let $X=(X_t)_{t\ge0}$ be a stable L\'{e}vy process of index $\alpha \in(1,2)$
with no negative jumps and let $S_t=\sup_{0\le s\le t}X_s$ denote its running
supremum for $t>0$. We show that the density function $f_t$ of $S_t$ can be
characterized as the unique solution to a weakly singular Volterra integral
equation of the first kind or, equivalently, as the unique solution to a
first-order Riemann--Liouville fractional differential equation satisfying a
boundary condition at zero. This yields an explicit series representation for
$f_t$. Recalling the familiar relation between $S_t$ and the first entry time
$\tau_x$ of $X$ into $[x,\infty)$, this further translates into an explicit
series representation for the density function of $\tau_x$.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:02:12 GMT"
},
{
"version": "v2",
"created": "Fri, 16 Nov 2007 12:21:47 GMT"
},
{
"version": "v3",
"created": "Fri, 26 Sep 2008 12:55:15 GMT"
}
] | 2008-09-26T00:00:00 | [
[
"Bernyk",
"Violetta",
""
],
[
"Dalang",
"Robert C.",
""
],
[
"Peskir",
"Goran",
""
]
] |
0706.1504 | George Bass Ph.D. | George E. Bass, Bernd Meibohm, James T. Dalton and Robert Sayre | Free Energy of Activation for the Comorosan Effect | 21 pages, 3 figures, 2 tables | null | null | null | q-bio.SC q-bio.BM | null | Initial reaction rate data for lactic dehydrogenase / pyruvate, lactic
dehydrogenase / lactate and malic dehydrogenase / malate enzyme reactions were
analyzed to obtain activation free energy changes of -329, -195 and -221
cal/mole, respectively, for rate increases associated with time-specific
irradiation of the crystalline substrates prior to dissolution and
incorporation in the reaction solutions. These energies, presumably, correspond
to conformational or vibrational changes in the reactants or the activated
complex. For the lactic dehydrogenase / pyruvate reaction, it is estimated that
on the order of 10% of the irradiation energy (546 nm, 400 footcandles for 5
seconds) would be required to produce the observed reaction rate increase if a
presumed photoproduct is consumed stoichiometrically with the pyruvate
substrate. These findings are consistent with the proposition that the observed
reaction rate enhancement involves photoproducts derived from oscillatory
atmospheric gas reactions at the crystalline enzyme substrate surfaces rather
than photo-excitations of the substrate molecules, per se.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:03:22 GMT"
}
] | 2007-06-12T00:00:00 | [
[
"Bass",
"George E.",
""
],
[
"Meibohm",
"Bernd",
""
],
[
"Dalton",
"James T.",
""
],
[
"Sayre",
"Robert",
""
]
] |
0706.1505 | Javier Rico | MAGIC Collaboration: J. Albert, et al | Very High Energy Gamma-ray Radiation from the Stellar-mass Black Hole
Cygnus X-1 | 4 ApJL-formatted pages, 4 figures. Revised version accepted for
publication at ApJL (26-06-2007) | Astrophys.J.665:L51-L54,2007 | 10.1086/521145 | null | astro-ph | null | We report on the results from the observations in very high energy band (VHE,
E_gamma > 100 GeV) of the black hole X-ray binary (BHXB) Cygnus X-1. The
observations were performed with the MAGIC telescope, for a total of 40 hours
during 26 nights, spanning the period between June and November 2006. Searches
for steady gamma-ray signals yielded no positive result and upper limits to the
integral flux ranging between 1 and 2% of the Crab nebula flux, depending on
the energy, have been established. We also analyzed each observation night
independently, obtaining evidence of gamma-ray signals at the 4.0 standard
deviations (sigma) significance level (3.2 sigma after trial correction) for
154 minutes effective on-time (EOT) on September 24 between 20h58 and 23h41
UTC, coinciding with an X-ray flare seen by RXTE, Swift and INTEGRAL. A search
for faster-varying signals within a night resulted in an excess with a
significance of 4.9 sigma (4.1 sigma after trial correction) for 79 minutes EOT
between 22h17 and 23h41 UTC. The measured excess is compatible with a
point-like source at the position of Cygnus X-1, and excludes the nearby radio
nebula powered by its relativistic jet. The differential energy spectrum is
well fitted by an unbroken power-law described by dN/(dA dt dE) = (2.3+- 0.6) x
10^{-12} (E/1 TeV)^{-3.2 +- 0.6}. This is the first experimental evidence of
VHE emission from a stellar-mass black hole, and therefore from a confirmed
accreting X-ray binary.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:19:54 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 15:33:20 GMT"
}
] | 2010-11-11T00:00:00 | [
[
"MAGIC Collaboration",
"",
""
],
[
"Albert",
"J.",
""
]
] |
0706.1506 | Henning Schomerus | John P Robinson, Henning Schomerus | Electronic transport in normal-conductor/graphene/normal-conductor
junctions and conditions for insulating behavior at a finite charge-carrier
density | 11 pages, 7 figures, published version including a section on the
sharpness of thresholds | Phys. Rev. B 76, 115430 (2007) | 10.1103/PhysRevB.76.115430 | null | cond-mat.mes-hall | null | We investigate the conductance of normal-conductor/graphene/normal-conductor
(NGN) junctions for arbitrary on-site potentials in the normal and graphitic
parts of the system. We find that a ballistic NGN junction can display
insulating behavior even when the charge-carrier density in the graphene part
is finite. This effect originates in the different k intervals supporting
propagating modes in graphene and a normal conductor, and persists for moderate
levels of bulk, edge, or interface disorder. The ensuing conductance thresholds
could be used as an electronic tool to map out details of the graphene band
structure in absolute k space.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:08:46 GMT"
},
{
"version": "v2",
"created": "Thu, 11 Oct 2007 16:33:22 GMT"
}
] | 2007-10-11T00:00:00 | [
[
"Robinson",
"John P",
""
],
[
"Schomerus",
"Henning",
""
]
] |
0706.1507 | Morten Bache | M. Bache, J. Moses, F. W. Wise | Scaling laws for soliton pulse compression by cascaded quadratic
nonlinearities | 11 pages, 8 figures, resubmitted version, to appear in October issue
of J. Opt. Soc. Am. B. Substantially revised, updated model | Journal of the Optical Society of America B 24, 2752-2762 (2007) | 10.1364/JOSAB.24.002752 | null | physics.optics | null | We present a detailed study of soliton compression of ultra-short pulses
based on phase-mismatched second-harmonic generation (\textit{i.e.}, the
cascaded quadratic nonlinearity) in bulk quadratic nonlinear media. The
single-cycle propagation equations in the temporal domain including
higher-order nonlinear terms are presented. The balance between the quadratic
(SHG) and the cubic (Kerr) nonlinearity plays a crucial role: we define an
effective soliton number -- related to the difference between the SHG and the
Kerr soliton numbers -- and show that it has to be larger than unity for
successful pulse compression to take place. This requires that the phase
mismatch be below a critical level, which is high in a material where the
quadratic nonlinearity dominates over the cubic Kerr nonlinearity. Through
extensive numerical simulations we find dimensionless scaling laws, expressed
through the effective soliton number, which control the behaviour of the
compressed pulses. These laws hold in the stationary regime, in which
group-velocity mismatch effects are small, and they are similar to the ones
observed for fiber soliton compressors. The numerical simulations indicate that
clean compressed pulses below two optical cycles can be achieved in a
$\beta$-barium borate crystal at appropriate wavelengths, even for picosecond
input pulses.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:13:17 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 07:53:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Bache",
"M.",
""
],
[
"Moses",
"J.",
""
],
[
"Wise",
"F. W.",
""
]
] |
0706.1508 | Graeme Mitchison | Graeme Mitchison, Richard Jozsa and Sandu Popescu | Sequential weak measurement | null | null | 10.1103/PhysRevA.76.062105 | null | quant-ph | null | The notion of weak measurement provides a formalism for extracting
information from a quantum system in the limit of vanishing disturbance to its
state. Here we extend this formalism to the measurement of sequences of
observables. When these observables do not commute, we may obtain information
about joint properties of a quantum system that would be forbidden in the usual
strong measurement scenario. As an application, we provide a physically
compelling characterisation of the notion of counterfactual quantum
computation.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:19:23 GMT"
},
{
"version": "v2",
"created": "Fri, 3 Aug 2007 14:22:39 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Mitchison",
"Graeme",
""
],
[
"Jozsa",
"Richard",
""
],
[
"Popescu",
"Sandu",
""
]
] |
0706.1509 | Sergio Caracciolo | Sergio Caracciolo, Alan D. Sokal, Andrea Sportiello | Grassmann Integral Representation for Spanning Hyperforests | 50 pages, it uses some latex macros. Accepted for publication on J.
Phys. A | J.Phys.A40:13799-13835,2007 | 10.1088/1751-8113/40/46/001 | null | math-ph cond-mat.stat-mech hep-lat math.CO math.MP | null | Given a hypergraph G, we introduce a Grassmann algebra over the vertex set,
and show that a class of Grassmann integrals permits an expansion in terms of
spanning hyperforests. Special cases provide the generating functions for
rooted and unrooted spanning (hyper)forests and spanning (hyper)trees. All
these results are generalizations of Kirchhoff's matrix-tree theorem.
Furthermore, we show that the class of integrals describing unrooted spanning
(hyper)forests is induced by a theory with an underlying OSP(1|2)
supersymmetry.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:30:49 GMT"
},
{
"version": "v2",
"created": "Tue, 16 Oct 2007 09:56:05 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Caracciolo",
"Sergio",
""
],
[
"Sokal",
"Alan D.",
""
],
[
"Sportiello",
"Andrea",
""
]
] |
0706.1510 | Compiegne Mathieu | M. Compiegne (1), A. Abergel (1), L. Verstraete (1), W. T. Reach (2),
E. Habart (1), J.D. Smith (3), F. Boulanger (1), C. Joblin (4) ((1) IAS Orsay
FRANCE, (2) SSC Pasadena USA, (3) Steward Observatory Tucson USA, (4) CESR
Toulouse FRANCE) | Aromatic emission from the ionised mane of the Horsehead nebula | 9 pages, 9 figures, accepted for publication in A&A | null | 10.1051/0004-6361:20066172 | null | astro-ph | null | We study the evolution of the Aromatic Infrared Bands (AIBs) emitters across
the illuminated edge of the Horsehead nebula and especially their survival and
properties in the HII region. We present spectral mapping observations taken
with the Infrared Spectrograph (IRS) at wavelengths 5.2-38 microns. A strong
AIB at 11.3 microns is detected in the HII region, relative to the other AIBs
at 6.2, 7.7 and 8.6 microns. The intensity of this band appears to be
correlated with the intensity of the [NeII] at 12.8 microns and of Halpha,
which shows that the emitters of the 11.3 microns band are located in the
ionised gas. The survival of PAHs in the HII region could be due to the
moderate intensity of the radiation field (G0 about 100) and the lack of
photons with energy above about 25eV. The enhancement of the intensity of the
11.3 microns band in the HII region, relative to the other AIBs can be
explained by the presence of neutral PAHs. Our observations highlight a
transition region between ionised and neutral PAHs observed with ideal
conditions in our Galaxy. A scenario where PAHs can survive in HII regions and
be significantly neutral could explain the detection of a prominent 11.3
microns band in other Spitzer observations.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:25:15 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Compiegne",
"M.",
""
],
[
"Abergel",
"A.",
""
],
[
"Verstraete",
"L.",
""
],
[
"Reach",
"W. T.",
""
],
[
"Habart",
"E.",
""
],
[
"Smith",
"J. D.",
""
],
[
"Boulanger",
"F.",
""
],
[
"Joblin",
"C.",
""
]
] |
0706.1511 | Leonard S. Kisslinger | Ernest M. Henley (Department of Physics, University of Washington),
Mikkel B. Johnson (Los Alamos National Laboratory), Leonard S. Kisslinger
(Department of Physics, Carnegie Mellon University) | Pulsar Kicks With Modified URCA and Electrons in Landau Levels | 11 pages, 6 figures | Phys.Rev.D76:125007,2007 | 10.1103/PhysRevD.76.125007 | null | astro-ph | null | We derive the energy asymmetry given the proto-neutron star during the time
when the neutrino sphere is near the surface of the proto-neutron star, using
the modified URCA process. The electrons produced with the anti-neutrinos are
in Landau levels due to the strong magnetic field, and this leads to asymmetry
in the neutrino momentum, and a pulsar kick. The magnetic field must be strong
enough for a large fraction of the eletrons to be in the lowest Landau level,
however, there is no direct dependence of our pulsar velocity on the strength
of the magnetic field. Our main prediction is that the large pulsar kicks start
at about 10 s and last for about 10 s, with the corresponding neutrinos
correlated in the direction of the magnetic field. We predict a pulsar velocity
of 1.03 $\times 10^{-4} (T/10^{10}K)^7$ km/s, which reaches 1000 km/s if T
$\simeq 9.96 \times 10^{10}$ K.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 19:48:09 GMT"
},
{
"version": "v2",
"created": "Tue, 28 Aug 2007 18:21:57 GMT"
},
{
"version": "v3",
"created": "Mon, 3 Dec 2007 19:03:36 GMT"
}
] | 2008-12-18T00:00:00 | [
[
"Henley",
"Ernest M.",
"",
"Department of Physics, University of Washington"
],
[
"Johnson",
"Mikkel B.",
"",
"Los Alamos National Laboratory"
],
[
"Kisslinger",
"Leonard S.",
"",
"Department of Physics, Carnegie Mellon University"
]
] |
0706.1512 | Jeremy Avigad | Jeremy Avigad, Philipp Gerhardy and Henry Towsner | Local stability of ergodic averages | Minor errors corrected. To appear in Transactions of the AMS | Trans. Amer. Math. Soc. 362 (2010), 261-288 | 10.1090/S0002-9947-09-04814-4 | null | math.DS math.LO | null | The mean ergodic theorem is equivalent to the assertion that for every
function K and every epsilon, there is an n with the property that the ergodic
averages A_m f are stable to within epsilon on the interval [n,K(n)]. We show
that even though it is not generally possible to compute a bound on the rate of
convergence of a sequence of ergodic averages, one can give explicit bounds on
n in terms of K and || f || / epsilon. This tells us how far one has to search
to find an n so that the ergodic averages are "locally stable" on a large
interval. We use these bounds to obtain a similarly explicit version of the
pointwise ergodic theorem, and show that our bounds are qualitatively different
from ones that can be obtained using upcrossing inequalities due to Bishop and
Ivanov. Finally, we explain how our positive results can be viewed as an
application of a body of general proof-theoretic methods falling under the
heading of "proof mining."
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:31:52 GMT"
},
{
"version": "v2",
"created": "Thu, 23 Aug 2007 16:05:58 GMT"
},
{
"version": "v3",
"created": "Fri, 2 May 2008 13:45:10 GMT"
},
{
"version": "v4",
"created": "Fri, 9 May 2008 17:02:58 GMT"
}
] | 2016-07-15T00:00:00 | [
[
"Avigad",
"Jeremy",
""
],
[
"Gerhardy",
"Philipp",
""
],
[
"Towsner",
"Henry",
""
]
] |
0706.1513 | Cecilia Chirenti | Cecilia B. M. H. Chirenti and Luciano Rezzolla | How to tell a gravastar from a black hole | 16 pages, 13 figures, minor improvement | Class.Quant.Grav.24:4191-4206,2007 | 10.1088/0264-9381/24/16/013 | null | gr-qc astro-ph | null | Gravastars have been recently proposed as potential alternatives to explain
the astrophysical phenomenology traditionally associated to black holes,
raising the question of whether the two objects can be distinguished at all.
Leaving aside the debate about the processes that would lead to the formation
of a gravastar and the astronomical evidence in their support, we here address
two basic questions: Is a gravastar stable against generic perturbations? If
stable, can an observer distinguish it from a black hole of the same mass? To
answer these questions we construct a general class of gravastars and determine
the conditions they must satisfy in order to exist as equilibrium solutions of
the Einstein equations. For such models we perform a systematic stability
analysis against axial-perturbations, computing the real and imaginary parts of
the eigenfrequencies. Overall, we find that gravastars are stable to axial
perturbations, but also that their quasi-normal modes differ from those of a
black hole of the same mass and thus can be used to discern, beyond dispute, a
gravastar from a black hole.
| [
{
"version": "v1",
"created": "Mon, 11 Jun 2007 16:35:46 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Jun 2007 17:43:53 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Chirenti",
"Cecilia B. M. H.",
""
],
[
"Rezzolla",
"Luciano",
""
]
] |
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