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| versions
list | update_date
timestamp[s] | authors_parsed
sequence |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0706.2814 | Baohua Fu | Baohua Fu (LMJL), Fabien Herbaut (GRIM) | On the tautological ring of a Jacobian modulo rational equivalence | 10p | null | null | null | math.AG | null | We consider the Chow ring with rational coefficients of the Jacobian of a
curve. Assume D is a divisor in a base point free g^r_d of the curve such that
the canonical divisor K is a multiple of the divisor D. We find relations
between tautological cycles. We give applications for curves having a degree d
covering of P^1 whose ramification points are all of order d, and then for
hyperelliptic curves.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:12:54 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Fu",
"Baohua",
"",
"LMJL"
],
[
"Herbaut",
"Fabien",
"",
"GRIM"
]
] |
0706.2815 | Ling-Fong Li | Ling-Fong Li | On Hyperon Decays Involving Two Charged Leptons | null | null | null | null | hep-ph | null | The hyperon decays with 2 negative charged leptons in the final states can be
of interest as possible tests for the Majorana netrinos. The study of these
decays are complementary to the double beta decays of heavy nuclei.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:21:14 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Li",
"Ling-Fong",
""
]
] |
0706.2816 | Axel Kleinschmidt | Claudia Colonnello, Axel Kleinschmidt | Ehlers symmetry at the next derivative order | 13 pages. v2: updated reference | JHEP 0708:078,2007 | 10.1088/1126-6708/2007/08/078 | AEI-2007-88 | hep-th | null | We analyse four-dimensional gravity in the presence of general curvature
squared corrections and show that Ehlers' SL(2,R) symmetry, which appears in
the reduction of standard gravity to three dimensions, is preserved by the
correction terms. The mechanism allowing this is a correction of the SL(2,R)
transformation laws which resolves problems with the different scaling
behaviour of various terms occurring in the reduction.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:34:28 GMT"
},
{
"version": "v2",
"created": "Fri, 29 Jun 2007 14:47:00 GMT"
}
] | 2009-04-30T00:00:00 | [
[
"Colonnello",
"Claudia",
""
],
[
"Kleinschmidt",
"Axel",
""
]
] |
0706.2817 | Peter Gacs | Peter Gacs | The angel wins | 28 pages, 8 figures | null | null | null | math.CO | null | The angel-devil game is played on an infinite two-dimensional ``chessboard''.
The squares of the board are all white at the beginning. The players called
angel and devil take turns in their steps. When it is the devil's turn, he can
turn a square black. The angel always stays on a white square, and when it is
her turn she can fly at a distance of at most J steps (each of which can be
horizontal, vertical or diagonal) to a new white square. Here J is a constant.
The devil wins if the angel does not find any more white squares to land on.
The result of the paper is that if J is sufficiently large then the angel has a
strategy such that the devil will never capture her. This deceptively
easy-sounding result has been a conjecture, surprisingly, for about thirty
years. Several other independent solutions have appeared simultaneously, some
of them prove that J=2 is sufficient (see the Wikipedia on the angel problem).
Still, it is hoped that the hierarchical solution presented here may prove
useful for some generalizations.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:42:28 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gacs",
"Peter",
""
]
] |
0706.2818 | Alberto Imparato | A. Imparato, A. Pelizzola, M. Zamparo | Protein mechanical unfolding: a model with binary variables | null | J. Chem. Phys. 127, 145105 (2007) | 10.1063/1.2776271 | null | cond-mat.soft q-bio.BM | null | A simple lattice model, recently introduced as a generalization of the
Wako--Sait\^o model of protein folding, is used to investigate the properties
of widely studied molecules under external forces. The equilibrium properties
of the model proteins, together with their energy landscape, are studied on the
basis of the exact solution of the model. Afterwards, the kinetic response of
the molecules to a force is considered, discussing both force clamp and dynamic
loading protocols and showing that theoretical expectations are verified. The
kinetic parameters characterizing the protein unfolding are evaluated by using
computer simulations and agree nicely with experimental results, when these are
available. Finally, the extended Jarzynski equality is exploited to investigate
the possibility of reconstructing the free energy landscape of proteins with
pulling experiments.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:32:21 GMT"
}
] | 2007-10-16T00:00:00 | [
[
"Imparato",
"A.",
""
],
[
"Pelizzola",
"A.",
""
],
[
"Zamparo",
"M.",
""
]
] |
0706.2819 | Andriy Zhugayevych | A. Yurachkivsky, A. Zhugayevych | Approximate calculation of operator semigroups by perturbation of
generators | 6 pages, no figures | Dopovidi Natsionalnoi Akademii Nauk Ukrainy [Reports Nat. Acad.
Sci. Ukr.], 2003, No.11, p. 27 | null | null | math.FA | null | Let $\Omega$ be an operator semigroup with generator $A$ in a sequentially
complete locally convex topological vector space $E$. For a semigroup with
generator $A+D$, where $D$ is a bounded linear operator on $E$, two integral
equations are derived. A theorem on continuous dependence of a semigroup on its
generator is proved. An application to random walk on $\mathbb{Z}$ is given.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:36:06 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Yurachkivsky",
"A.",
""
],
[
"Zhugayevych",
"A.",
""
]
] |
0706.2820 | Patrick Warren | Patrick B. Warren, Frantisek Stepanek | The wall shear rate distribution for flow in random sphere packings | 4 pages, 3 figures, 1 table, RevTeX 4; significantly revised with
significantly extended scope | null | 10.1103/PhysRevLett.100.084501 | null | cond-mat.soft cond-mat.stat-mech | null | The wall shear rate distribution P(gamma) is investigated for pressure-driven
Stokes flow through random arrangements of spheres at packing fractions 0.1 <=
phi <= 0.64. For dense packings, P(gamma) is monotonic and approximately
exponential. As phi --> 0.1, P(gamma) picks up additional structure which
corresponds to the flow around isolated spheres, for which an exact result can
be obtained. A simple expression for the mean wall shear rate is presented,
based on a force-balance argument.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:42:03 GMT"
},
{
"version": "v2",
"created": "Mon, 22 Oct 2007 16:06:23 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Warren",
"Patrick B.",
""
],
[
"Stepanek",
"Frantisek",
""
]
] |
0706.2821 | Jane MacGibbon | Jane H MacGibbon | Black Hole Entropy Constraints on Variation of the Gravitational
Constant | 6 Pages | null | null | null | astro-ph gr-qc | null | Here we apply the Generalized Second Law of Thermodynamics (GSL) to black
holes accreting and emitting in the present Universe and derive upper limits on
the variation in the gravitational constant G. The limits depend on how the
gravitational mass M varies with G. Parameterizing M goes as G^n, if n > -1/2
(including n = 0), the GSL applied to the full range of black holes
theoretically allowed in the present Universe does not constrain an increase in
G but any decrease must be less than about |(1/G) dG/dt| = 10^-52 per second.
If n < -1/2, the GSL does not constrain a decrease in G but any increase must
be less than about |(1/G) dG/dt| = 10^-52 per second. At earlier redshifts,
these constraints weaken as z^3. If n = -1/2, the GSL does not constrain a
decrease but any increase must be less than about |(1/G) dG/dt| = (1/t). If the
mass range is restricted to those black holes which have been astronomically
observed, the present constraints on n > -1/2 and n < -1/2 are only weakened by
a factor of about 10^8 with the tightest constraints coming from stellar mass
black holes and the n = -1/2 bound does not change. The stellar mass black hole
limits should constrain the variation of G in Standard Model physics and all
extension models which approximate classical physics on astronomical scales.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:43:50 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"MacGibbon",
"Jane H",
""
]
] |
0706.2822 | Uli Zeitler | A.J.M. Giesbers, U. Zeitler, M.I. Katsnelson, L.A. Ponomarenko, T.M.G.
Mohiuddin, and J.C. Maan | Quantum-Hall activation gaps in graphene | 4 pages, 4 figures, updated version after review, accepted for PRL | Phys. Rev. Lett. 99, 206803 (2007) | 10.1103/PhysRevLett.99.206803 | null | cond-mat.mes-hall | null | We have measured the quantum-Hall activation gaps in graphene at filling
factors $\nu=2$ and $\nu=6$ for magnetic fields up to 32 T and temperatures
from 4 K to 300 K. The $\nu =6$ gap can be described by thermal excitation to
broadened Landau levels with a width of 400 K. In contrast, the gap measured at
$\nu=2$ is strongly temperature and field dependent and approaches the expected
value for sharp Landau levels for fields $B > 20$ T and temperatures $T > 100$
K. We explain this surprising behavior by a narrowing of the lowest Landau
level.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:47:13 GMT"
},
{
"version": "v2",
"created": "Fri, 12 Oct 2007 15:53:01 GMT"
}
] | 2007-11-19T00:00:00 | [
[
"Giesbers",
"A. J. M.",
""
],
[
"Zeitler",
"U.",
""
],
[
"Katsnelson",
"M. I.",
""
],
[
"Ponomarenko",
"L. A.",
""
],
[
"Mohiuddin",
"T. M. G.",
""
],
[
"Maan",
"J. C.",
""
]
] |
0706.2823 | Procheta Mallik | John C. Brown and Procheta C.V. Mallik | Non-thermal recombination - a neglected source of flare hard X-rays and
fast electron diagnostic | 13 pages, 2 tables, 9 figures, Accepted for publication in A&A | null | 10.1051/0004-6361:20078103 | null | astro-ph | null | Context. Flare Hard X-Rays (HXRs) from non-thermal electrons are commonly
treated as solely bremsstrahlung (f-f), recombination (f-b) being neglected.
This assumption is shown to be substantially in error, especially in hot
sources, mainly due to recombination onto Fe ions.
Aims. We analyse the effects on HXR spectra and electron diagnostics by
including non-thermal recombination onto heavy elements in our model.
Methods. Using Kramers hydrogenic cross sections with effective Z, we
calculate f-f and f-b spectra for power-law electron spectra, in both thin and
thick target limits, and for Maxwellians, with summation over all important
ions.
Results. We find that non-thermal electron recombination, especially onto Fe,
must, in general, be included together with f-f, for reliable spectral
interpretation, when the HXR source is hot. f-b contribution is greatest when
the electron spectral index is large, and any low energy cut-off small. f-b
spectra recombination edges mean a cut-off in F(E) appears as a HXR feature at
Photon energy = Ec + Vz, offering an Ec diagnostic. Including f-b lowers,
greatly in some cases, the F(E) needed for prescribed HXR fluxes and, even when
small, seriously distorts F(E) as inferred by inversion or forward fitting
based on f-f alone.
Conclusions. f-b recombination from non-thermal electrons can be an important
contributor to HXR spectra and should be included in spectral analyses,
especially for hot sources. Accurate results will require use of better cross
sections than ours and consideration of source ionisation structure.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:30:10 GMT"
},
{
"version": "v2",
"created": "Tue, 5 Feb 2008 12:48:03 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Brown",
"John C.",
""
],
[
"Mallik",
"Procheta C. V.",
""
]
] |
0706.2824 | Cyrille Chavet | Cyrille Chavet (LESTER, STM), Philippe Coussy (LESTER), Pascal Urard
(STM), Eric Martin (LESTER) | M\'ethodologie de mod\'elisation et d'impl\'ementation d'adaptateurs
spatio-temporels | null | Actes de la conference MajecSTIC 2005 (16/11/2005) 151 | null | null | cs.AR | null | The re-use of pre-designed blocks is a well-known concept of the software
development. This technique has been applied to System-on-Chip (SoC) design
whose complexity and heterogeneity are growing. The re-use is made thanks to
high level components, called virtual components (IP), available in more or
less flexible forms. These components are dedicated blocks: digital signal
processing (DCT, FFT), telecommunications (Viterbi, TurboCodes),... These
blocks rest on a model of fixed architecture with very few degrees of
personalization. This rigidity is particularly true for the communication
interface whose orders of acquisition and production of data, the temporal
behavior and protocols of exchanges are fixed. The successful integration of
such an IP requires that the designer (1) synchronizes the components (2)
converts the protocols between "incompatible" blocks (3) temporizes the data to
guarantee the temporal constraints and the order of the data. This phase
remains however very manual and source of errors. Our approach proposes a
formal modeling, based on an original Ressource Compatibility Graph. The
synthesis flow is based on a set of transformations of the initial graph to
lead to an interface architecture allowing the space-time adaptation of the
data exchanges between several components.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:56:43 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Chavet",
"Cyrille",
"",
"LESTER, STM"
],
[
"Coussy",
"Philippe",
"",
"LESTER"
],
[
"Urard",
"Pascal",
"",
"STM"
],
[
"Martin",
"Eric",
"",
"LESTER"
]
] |
0706.2825 | Konstantinos Kanakoglou | K. Kanakoglou, C. Daskaloyannis | Graded structure and Hopf structures in parabosonic algebra. An
alternative approach to bosonisation | 12 pages, Talk presented at the International Conference: "New
techniques in Hopf algebras and graded ring theory", Brussels, September
19-23, 2006. Submitted for publication at the proceedings | New Techn. in Hopf Alg. and Graded Ring Theory, eds.: S.
Caenepeel, F. van Oystayen, Royal Flemish Academy of Belgium, Brussels,
p.105-116, 2007 | null | null | math-ph hep-th math.MP math.QA | null | Parabosonic algebra in infinite degrees of freedom is presented as a
generalization of the bosonic algebra, from the viewpoints of both physics and
mathematics. The notion of super-Hopf algebra is shortly discussed and the
super-Hopf algebraic structure of the parabosonic algebra is established
(without appealing to its Lie superalgebraic structure). Two possible variants
of the parabosonic algebra are presented and their (ordinary) Hopf algebraic
structure is estabished: The first is produced by "bosonising" the original
super-Hopf algebra, while the second is constructed via a slightly different
path.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 15:58:31 GMT"
}
] | 2012-05-10T00:00:00 | [
[
"Kanakoglou",
"K.",
""
],
[
"Daskaloyannis",
"C.",
""
]
] |
0706.2826 | Kevin Rapedius | K. Rapedius, H. J. Korsch | Barrier transmission for the one-dimensional nonlinear Schr\"odinger
equation: resonances and transmission profiles | 9 pages, 6 figures, 1 table | Phys. Rev. A 77, 063610 (2008) | 10.1103/PhysRevA.77.063610 | null | cond-mat.other | null | The stationary nonlinear Schr\"odinger equation (or Gross-Pitaevskii
equation) for one-dimensional potential scattering is studied. The nonlinear
transmission function shows a distorted profile, which differs from the
Lorentzian one found in the linear case. This nonlinear profile function is
analyzed and related to Siegert type complex resonances. It is shown, that the
characteristic nonlinear profile function can be conveniently described in
terms of skeleton functions depending on a few instructive parameters. These
skeleton functions also determine the decay behavior of the underlying
resonance state. Furthermore we extend the Siegert method for calculating
resonances, which provides a convenient recipe for calculating nonlinear
resonances. Applications to a double Gaussian barrier and a square well
potential illustrate our analysis.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:23:43 GMT"
},
{
"version": "v2",
"created": "Wed, 13 Feb 2008 15:04:13 GMT"
}
] | 2008-08-06T00:00:00 | [
[
"Rapedius",
"K.",
""
],
[
"Korsch",
"H. J.",
""
]
] |
0706.2827 | Nikita Semenov | Viktor Petrov, Nikita Semenov | Higher Tits indices of algebraic groups | 29 pages, Appendix by Mathieu Florence | null | null | null | math.AG | null | Let G be a semisimple algebraic group over a field k. We introduce the higher
Tits indices of G as the set of all Tits indices of G over all field extensions
K/k. In the context of quadratic forms this notion coincides with the notion of
the higher Witt indices introduced by M. Knebusch and classified by N. Karpenko
and A. Vishik. We classify the higher Tits indices for exceptional algebraic
groups. Our main tools involve the Chow groups and the Chow motives of
projective homogeneous varieties, Steenrod operations, and the notion of the
J-invariant of algebraic groups.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:09:57 GMT"
},
{
"version": "v2",
"created": "Mon, 14 Jan 2008 16:51:29 GMT"
},
{
"version": "v3",
"created": "Wed, 16 Jan 2008 10:57:50 GMT"
}
] | 2008-01-16T00:00:00 | [
[
"Petrov",
"Viktor",
""
],
[
"Semenov",
"Nikita",
""
]
] |
0706.2828 | Krzysztof Klosin | Krzysztof Klosin | Adelic Maass spaces on U(2,2) | 15 pages | null | null | null | math.NT math.RT | null | Generalizing the results of Kojima, Gritsenko and Krieg, we define an adelic
version of the Maass space for hermitian modular forms of weight k regarded as
functions on adelic points of the quasi-split unitary group U(2,2) associated
with an imaginary quadratic extension F/Q of discriminant D_F. When the class
number h_F of F is odd, we show that the Maass space is invariant under the
action of the local Hecke algebras of U(2,2)(Q_p) for all p not dividing D_F.
As a consequence we obtain a Hecke-equivariant injective map from the Maass
space to the h_F-fold direct product of the space of elliptic modular forms of
weight k-1 and level D_F.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:19:11 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Klosin",
"Krzysztof",
""
]
] |
0706.2829 | Jos\'e M. Figueroa-O'Farrill | Jos\'e Figueroa-O'Farrill | A geometric construction of the exceptional Lie algebras F4 and E8 | 12 pages | Commun.Math.Phys.283:663-674,2008 | 10.1007/s00220-008-0581-7 | EMPG-07-12 | math.DG hep-th math.RT | null | We present a geometric construction of the exceptional Lie algebras F4 and E8
starting from the round 8- and 15-spheres, respectively, inspired by the
construction of the Killing superalgebra of a supersymmetric supergravity
background. (There is no supergravity in the paper.)
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:19:35 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Figueroa-O'Farrill",
"José",
""
]
] |
0706.2830 | Dan Solomon | Dan Solomon | A new look at the problem of gauge invariance in quantum field theory | Accepted by Physica Scripta. 27 pages | Phys.Scripta.76:64-71,2007 | 10.1088/0031-8949/76/1/013 | null | quant-ph | null | Quantum field theory is assumed to be gauge invariant. However it is well
known that when certain quantities are calculated using perturbation theory the
results are not gauge invariant. The non-gauge invariant terms have to be
removed in order to obtain a physically correct result. In this paper we will
examine this problem and determine why a theory that is supposed to be gauge
invariant produces non-gauge invariant results.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:29:11 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Solomon",
"Dan",
""
]
] |
0706.2831 | Stephen A. Fulling | Stephen A. Fulling | Vacuum Energy as Spectral Geometry | This is a contribution to the Proceedings of the 2007 Midwest
Geometry Conference in honor of Thomas P. Branson, published in SIGMA
(Symmetry, Integrability and Geometry: Methods and Applications) at
http://www.emis.de/journals/SIGMA/ | SIGMA 3 (2007), 094, 23 pages | 10.3842/SIGMA.2007.094 | null | math-ph math.DG math.MP | null | Quantum vacuum energy (Casimir energy) is reviewed for a mathematical
audience as a topic in spectral theory. Then some one-dimensional systems are
solved exactly, in terms of closed classical paths and periodic orbits. The
relations among local spectral densities, energy densities, global eigenvalue
densities, and total energies are demonstrated. This material provides
background and motivation for the treatment of higher-dimensional systems
(self-adjoint second-order partial differential operators) by semiclassical
approximation and other methods.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:31:15 GMT"
},
{
"version": "v2",
"created": "Wed, 26 Sep 2007 07:36:47 GMT"
}
] | 2008-04-25T00:00:00 | [
[
"Fulling",
"Stephen A.",
""
]
] |
0706.2832 | Aron L. Soha | CDF Collaboration, T. Aaltonen, et al | Search for Third Generation Vector Leptoquarks in p anti-p Collisions at
sqrt(s) = 1.96 TeV | 7 pages, 2 figures, submitted to PRL | Phys.Rev.D77:091105,2008 | 10.1103/PhysRevD.77.091105 | FERMILAB-PUB-07-207-E | hep-ex | null | We describe a search for a third generation vector leptoquark (VLQ3) that
decays to a b quark and tau lepton using the CDF II detector and 322 pb^(-1) of
integrated luminosity from the Fermilab Tevatron. Vector leptoquarks have been
proposed in many extensions of the standard model (SM). Observing a number of
events in agreement with SM expectations, assuming Yang-Mills (minimal)
couplings, we obtain the most stringent upper limit on the VLQ3 pair production
cross section of 344 fb (493 fb) and lower limit on the VLQ3 mass of 317
GeV/c^2 (251 GeV/c^2) at 95% C.L.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:33:34 GMT"
}
] | 2009-01-12T00:00:00 | [
[
"CDF Collaboration",
"",
""
],
[
"Aaltonen",
"T.",
""
]
] |
0706.2833 | Marcela Grether | M. Grether, M. de Llano, and George A. Baker Jr | Bose-Einstein Condensation in the Relativistic Ideal Bose Gas | 10 pages, 4 figures | Phys.Rev.Lett.99:200406,2007 | 10.1103/PhysRevLett.99.200406 | null | cond-mat.supr-con | null | The Bose-Einstein condensation (BEC) critical temperature in a relativistic
ideal Bose gas of identical bosons, with and without the antibosons expected to
be pair-produced abundantly at sufficiently hot temperatures, is exactly
calculated for all boson number-densities, all boson point rest masses, and all
temperatures. The Helmholtz free energy at the critical BEC temperature is
found to be lower, thus implying that the omission of antibosons always leads
to the computation of a metastable state.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:52:14 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 17:36:37 GMT"
},
{
"version": "v3",
"created": "Wed, 27 Jun 2007 14:58:05 GMT"
},
{
"version": "v4",
"created": "Mon, 10 Dec 2007 20:04:34 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Grether",
"M.",
""
],
[
"de Llano",
"M.",
""
],
[
"Baker",
"George A.",
"Jr"
]
] |
0706.2834 | Pasquale Blasi | R. Aloisio (1), V. Berezinsky (1), P. Blasi (2), S. Ostapchenko (3)
((1) INFN/LNGS, (2)INAF/Arcetri, (3) Karlsruhe) | Signatures of the transition from galactic to extragalactic cosmic rays | Version accepted for publication in Physical Review D | Phys.Rev.D77:025007,2008 | 10.1103/PhysRevD.77.025007 | null | astro-ph | null | We discuss the signatures of the transition from galactic to extragalactic
cosmic rays in different scenarios, giving most attention to the dip scenario.
The dip is a feature in the diffuse spectrum of ultra-high energy (UHE) protons
in the energy range $1\times 10^{18} - 4\times 10^{19}$ eV, which is caused by
electron-positron pair production on the cosmic microwave background (CMB)
radiation. The dip scenario provides a simple physical description of the
transition from galactic to extragalactic cosmic rays. Here we summarize the
signatures of the pair production dip model for the transition, most notably
the spectrum, the anisotropy and the chemical composition. The main focus of
our work is however on the description of the features that arise in the
elongation rate and in the distribution of the depths of shower maximum $X_{\rm
max}$ in the dip scenario. We find that the curve for $X_{\max}(E)$ shows a
sharp increase with energy, which reflects a sharp transition from an iron
dominated flux at low energies to a proton dominated flux at $E\sim 10^{18}$
eV. We also discuss in detail the shape of the $X_{\max}$ distributions for
cosmic rays of given energy and demonstrate that this represents a powerful
tool to discriminate between the dip scenario and other possible models of the
transition.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:54:04 GMT"
},
{
"version": "v2",
"created": "Mon, 19 Nov 2007 22:00:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Aloisio",
"R.",
"",
"INFN/LNGS"
],
[
"Berezinsky",
"V.",
"",
"INFN/LNGS"
],
[
"Blasi",
"P.",
"",
"INAF/Arcetri"
],
[
"Ostapchenko",
"S.",
"",
"Karlsruhe"
]
] |
0706.2835 | Elias Gyftopoulos | Elias P. Gyftopoulos, Michael R. von Spakovsky | Comments on Extraction of Work from a Single Thermal Bath in the Quantum
Regime | 1 page | null | null | null | quant-ph | null | In a PRL [1], the authors claim to show that "the Clausius inequality can be
violated, and that it is even possible to extract work from a thermal bath by
cyclic variations of a parameter ("perpetuum mobile"), and that the physical
cause for this behavior is traced back to quantum coherence in the presence of
the nonequilibrium bath (sic)".
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 16:55:47 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 14:43:42 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
],
[
"von Spakovsky",
"Michael R.",
""
]
] |
0706.2836 | Markus Ahlers | M. Ahlers, H. Gies, J. Jaeckel, J. Redondo and A. Ringwald | Light from the Hidden Sector | 34 pages, 9 figures | Phys.Rev.D76:115005,2007 | 10.1103/PhysRevD.76.115005 | null | hep-ph hep-th | null | Optical precision experiments are a powerful tool to explore hidden sectors
of a variety of standard-model extensions with potentially tiny couplings to
photons. An important example is given by extensions involving an extra light
U(1) gauge degree of freedom, so-called paraphotons, with gauge-kinetic mixing
with the normal photon. These models naturally give rise to minicharged
particles which can be searched for with optical experiments. In this paper, we
study the effects of paraphotons in such experiments. We describe in detail the
role of a magnetic field for photon-paraphoton oscillations in models with
low-mass minicharged particles. In particular, we find that the upcoming
light-shining-through-walls experiments are sensitive to paraphotons and can
distinguish them from axion-like particles.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:00:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Ahlers",
"M.",
""
],
[
"Gies",
"H.",
""
],
[
"Jaeckel",
"J.",
""
],
[
"Redondo",
"J.",
""
],
[
"Ringwald",
"A.",
""
]
] |
0706.2837 | Michael Goodwin | Michael Goodwin, Charles Jenkins and Andrew Lambert | Improved detection of atmospheric turbulence with SLODAR | 17 pages, 8 figures | null | 10.1364/OE.15.014844 | null | astro-ph | null | We discuss several improvements in the detection of atmospheric turbulence
using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations
have shown strong ground-layer turbulence, which is beneficial to adaptive
optics. We show that current methods which neglect atmospheric propagation
effects can underestimate the strength of high altitude turbulence by up to ~
30%. We show that mirror and dome seeing turbulence can be a significant
fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also
demonstrate a novel technique to improve the nominal height resolution, by a
factor of 3, called Generalized SLODAR. This can be applied when sampling
high-altitude turbulence, where the nominal height resolution is the poorest,
or for resolving details in the important ground-layer.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:05:19 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Goodwin",
"Michael",
""
],
[
"Jenkins",
"Charles",
""
],
[
"Lambert",
"Andrew",
""
]
] |
0706.2838 | Alan de Oliveira Ms. | Alan Barros de Oliveira, Giancarlo Franzese, Paulo A. Netz, and Marcia
C. Barbosa | Water-like hierarchy of anomalies in a continuous spherical shouldered
potential | 27 pages, 9 figures. to appear in J. Chem. Phys | Journal of Chemical Physics 128, 064901 (2008) | 10.1063/1.2830706 | null | cond-mat.stat-mech cond-mat.soft | null | We investigate by molecular dynamics simulations a continuous isotropic
core-softened potential with attractive well in three dimensions, introduced by
Franzese [cond-mat/0703681, to appear on Journal of Molecular Liquids], that
displays liquid-liquid coexistence with a critical point and water-like density
anomaly. Here we find diffusion and structural anomalies. These anomalies occur
with the same hierarchy that characterizes water. Yet our analysis shows
differences with respect to the water case. Therefore, many of the anomalous
features of water could be present in isotropic systems with soft-core
attractive potentials, such as colloids or liquid metals, consistent with
recent experiments showing polyamorphism in metallic glasses.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:05:30 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 20:21:17 GMT"
},
{
"version": "v3",
"created": "Wed, 12 Dec 2007 10:58:10 GMT"
}
] | 2009-10-22T00:00:00 | [
[
"de Oliveira",
"Alan Barros",
""
],
[
"Franzese",
"Giancarlo",
""
],
[
"Netz",
"Paulo A.",
""
],
[
"Barbosa",
"Marcia C.",
""
]
] |
0706.2839 | Rajeev Raman | Naila Rahman and Rajeev Raman | Cache Analysis of Non-uniform Distribution Sorting Algorithms | The full version of our ESA 2000 paper (LNCS 1879) on this subject | null | null | null | cs.DS cs.PF | null | We analyse the average-case cache performance of distribution sorting
algorithms in the case when keys are independently but not necessarily
uniformly distributed. The analysis is for both `in-place' and `out-of-place'
distribution sorting algorithms and is more accurate than the analysis
presented in \cite{RRESA00}. In particular, this new analysis yields tighter
upper and lower bounds when the keys are drawn from a uniform distribution.
We use this analysis to tune the performance of the integer sorting algorithm
MSB radix sort when it is used to sort independent uniform floating-point
numbers (floats). Our tuned MSB radix sort algorithm comfortably outperforms a
cache-tuned implementations of bucketsort \cite{RR99} and Quicksort when
sorting uniform floats from $[0, 1)$.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:12:47 GMT"
},
{
"version": "v2",
"created": "Mon, 13 Aug 2007 22:57:01 GMT"
}
] | 2007-08-14T00:00:00 | [
[
"Rahman",
"Naila",
""
],
[
"Raman",
"Rajeev",
""
]
] |
0706.2840 | Jonathan Sondow | Jonathan Sondow | A Simple Counterexample to Havil's "Reformulation" of the Riemann
Hypothesis | Expanded from 2 to 7 pages, new title, added: exposition of the RH
and the alternating zeta function, proof that the corrected form of Havil's
conjecture is a true reformulation of the RH, 4 references, and
Acknowledgments | Elemente der Mathematik 67 (2012) 61-67 | null | null | math.NT math.GM math.HO | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is an elementary note. It corrects a mistake in the reformulation of the
Riemann Hypothesis in J. Havil's book Gamma: Exploring Euler's Constant.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:13:32 GMT"
},
{
"version": "v2",
"created": "Mon, 18 Oct 2010 04:44:05 GMT"
},
{
"version": "v3",
"created": "Tue, 30 Nov 2010 23:06:55 GMT"
}
] | 2012-05-09T00:00:00 | [
[
"Sondow",
"Jonathan",
""
]
] |
0706.2841 | Ivan Favero | Khaled Karrai, Ivan Favero, Constanze Metzger | Doppler controlled dynamics of a mirror attached to a spring | 4 pages, 1 figure | null | null | null | cond-mat.other | null | A laser beam directed at a mirror attached onto a flexible mount extracts
thermal energy from its mechanical Brownian motion by Doppler effect. For a
normal mirror the efficiency of this Doppler cooling is very weak and masked by
laser shot-noise. We find that it can become very efficient using a Bragg
mirror at the long wavelength edge of its band stop. The opposite effect of
cooling opens new routes for optical pumping of mechanical systems: a laser
pointing at a Bragg mirror and tuned at its short wavelength edge induces
amplification of the vibrational excitation of the mirror leading eventually to
its self-oscillation. This new effects rely on the strong dependency of the
Bragg mirror reflectivity on the wavelength.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:20:02 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Karrai",
"Khaled",
""
],
[
"Favero",
"Ivan",
""
],
[
"Metzger",
"Constanze",
""
]
] |
0706.2842 | Elias Gyftopoulos | Elias P. Gyftopoulos, Michael R. von Spakovsky | Comments on testing the violation of the Clausius inequality in
nanoscale electric circuits | 2 pages | null | null | null | quant-ph | null | The correct laws of thermodynamics, either classical or quantum without
probabilities of statistical quantum mechanics are valid for all systems, large
or small, including systems of one spin or one particle only. So no violations
can occur in nanoscale electric circuits.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:27:24 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
],
[
"von Spakovsky",
"Michael R.",
""
]
] |
0706.2843 | Steven R. Cranmer | Steven R. Cranmer (Harvard-Smithsonian CfA) | Turbulence in the Solar Corona | 6 pages, 1 figure (AIP 6x9 style), to appear in AIP Conference
Proceedings: "Turbulence and Nonlinear Processes in Astrophysical Plasmas"
(6th Annual IGPP International Astrophysics Conference), Waikiki, March
16-22, 2007 | AIPConf.Proc.932:271-276,2007 | 10.1063/1.2778974 | null | astro-ph | null | The solar corona has been revealed in the past decade to be a highly dynamic
nonequilibrium plasma environment. Both the loop-filled coronal base and the
extended acceleration region of the solar wind appear to be strongly turbulent,
but direct observational evidence for a cascade of fluctuation energy from
large to small scales is lacking. In this paper I will review the observations
of wavelike motions in the corona over a wide range of scales, as well as the
macroscopic effects of wave-particle interactions such as preferential ion
heating. I will also present a summary of recent theoretical modeling efforts
that seem to explain the time-steady properties of the corona (and the fast and
slow solar wind) in terms of an anisotropic MHD cascade driven by the partial
reflection of low-frequency Alfven waves propagating along the superradially
expanding solar magnetic field. Complete theoretical models are difficult to
construct, though, because many of the proposed physical processes act on a
multiplicity of spatial scales (from centimeters to solar radii) with feedback
effects not yet well understood. This paper is thus a progress report on
various attempts to couple these disparate scales.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:32:00 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cranmer",
"Steven R.",
"",
"Harvard-Smithsonian CfA"
]
] |
0706.2844 | Ivan Veseli\'c | Ton\'ci Antunovi\'c and Ivan Veseli\'c | Equality of Lifshitz and van Hove exponents on amenable Cayley graphs | null | Journal de Mathematiques Pures et Appliquees Volume 92, Issue 4,
October 2009, Pages 342-362 | 10.1016/j.matpur.2009.05.014 | null | math.SP math-ph math.GR math.MP | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the low energy asymptotics of periodic and random Laplace operators
on Cayley graphs of amenable, finitely generated groups. For the periodic
operator the asymptotics is characterised by the van Hove exponent or zeroth
Novikov-Shubin invariant. The random model we consider is given in terms of an
adjacency Laplacian on site or edge percolation subgraphs of the Cayley graph.
The asymptotic behaviour of the spectral distribution is exponential,
characterised by the Lifshitz exponent. We show that for the adjacency
Laplacian the two invariants/exponents coincide. The result holds also for more
general symmetric transition operators. For combinatorial Laplacians one has a
different universal behaviour of the low energy asymptotics of the spectral
distribution function, which can be actually established on quasi-transitive
graphs without an amenability assumption. The latter result holds also for long
range bond percolation models.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:47:54 GMT"
},
{
"version": "v2",
"created": "Mon, 20 Aug 2007 14:02:33 GMT"
},
{
"version": "v3",
"created": "Wed, 21 Jan 2009 18:03:31 GMT"
}
] | 2016-01-07T00:00:00 | [
[
"Antunović",
"Tonći",
""
],
[
"Veselić",
"Ivan",
""
]
] |
0706.2845 | Roland Gunesch | Roland Gunesch | Counting closed geodesics on rank one manifolds | 36 pages, 2 figures. See also
http://www.math.uni-hamburg.de/home/gunesch/ | null | null | null | math.DS math.DG | null | We establish a precise asymptotic formula for the number of homotopy classes
of periodic orbits for the geodesic flow on rank one manifolds of nonpositive
curvature. This extends a celebrated result of G. A. Margulis to the
nonuniformly hyperbolic case and strengthens previous results by G. Knieper. We
also establish some useful properties of the measure of maximal entropy.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:16:15 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gunesch",
"Roland",
""
]
] |
0706.2846 | Arturo De Pace | W.M. Alberico (1), A. Beraudo (2), A. De Pace (1) and A. Molinari (1)
((1) Dipartimento di Fisica Teorica, Universita' di Torino and INFN Sezione
di Torino, Italy, (2) ECT*, Trento, Italy) | Potential models and lattice correlators for quarkonia at finite
temperature | 4 pages, 2 figures | Phys.Rev.D77:017502,2008 | 10.1103/PhysRevD.77.017502 | null | hep-ph | null | We update our recent calculation of quarkonium Euclidean correlators at
finite temperatures in a potential model by including the effect of zero modes
in the lattice spectral functions. These contributions cure most of the
previously observed discrepancies with lattice calculations, supporting the use
of potential models at finite temperature as an important tool to complement
lattice studies.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:49:14 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Alberico",
"W. M.",
""
],
[
"Beraudo",
"A.",
""
],
[
"De Pace",
"A.",
""
],
[
"Molinari",
"A.",
""
]
] |
0706.2847 | Li Zeng | Li Zeng, E. Helgren, R. Islam, B. J. Wilkens, R. J. Culbertson, David
J. Smith, F. Hellman | Quenched magnetic moment in Mn-doped amorphous Si
(\textit{a}-Mn$_{x}$Si$_{1-x}$) across the metal-insulator transition | 8 figures | null | null | null | cond-mat.mtrl-sci cond-mat.str-el | null | The magnetic and electrical transport properties of Mn-doped amorphous
silicon (\textit{a-}Mn$_{x}$Si$_{1-x}$) thin films have been measured. The
magnetic susceptibility obeys the Curie-Weiss law for a wide range of $x$
(0.005-0.175) and the saturation moment is small. While all Mn atoms contribute
to the electrical transport, only a small fraction (interstitial Mn$^{2+}$
states with $J$=$S$=5/2) contribute to the magnetization. The majority of the
Mn atoms do not possess any magnetic moment, contrary to what is predicted by
the Ludwig-Woodbury model for Mn in crystalline silicon. Unlike
\textit{a-}Gd$_{x}$Si$_{1-x}$ films which have an enormous \textit{negative}
magnetoresistance, \textit{a-}Mn$_{x}$Si$_{1-x}$ films have only a small
\textit{positive} magnetoresistance, which can be understood by this quenching
of the Mn moment.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:49:52 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Zeng",
"Li",
""
],
[
"Helgren",
"E.",
""
],
[
"Islam",
"R.",
""
],
[
"Wilkens",
"B. J.",
""
],
[
"Culbertson",
"R. J.",
""
],
[
"Smith",
"David J.",
""
],
[
"Hellman",
"F.",
""
]
] |
0706.2848 | Elias Gyftopoulos | Elias P. Gyftopoulos | Quantum Uncertainty and Nonlocality: Are they Correctly Understood? | 2 pages | null | null | null | quant-ph | null | In a brief article [1], Seife refers to works by Einstein and Schroedinger
and concludes that there is a relentless murmur of confusion underneath the
chorus of praise for quantum theory. It is noteworthy that a "murmur" is not
necessarily a cause for replacement of any scientific theory, and that the
issues raised by Einstein, Podolsky, and Rosen, and Schroedinger's responses to
the EPR paper have been satisfactorily resolved by Gyftopoulos and von
Spakovsky [2] in a manner that renders the relentless murmur mute and
unwarranted.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:49:52 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
]
] |
0706.2849 | Asen Pashov | A. Pashov, O. Docenko, M. Tamanis, R. Ferber, H. Knoeckel, E. Tiemann | The coupling of the X$^{1}\Sigma ^{+}$ and a$^{3}\Sigma ^{+}$ states of
KRb | 14 pages, 5 figures | null | 10.1103/PhysRevA.76.022511 | null | physics.atom-ph | null | A comprehensive study of the electronic states at the 4s+5s asymptote in KRb
is presented. Abundant spectroscopic data on the \astate state were collected
by Fourier-transform spectroscopy which allow to determine an accurate
experimental potential energy curve up to 14.8 \AA . The existing data set (C.
Amiot et al. J. Chem. Phys. 112, 7068 (2000)) on the ground state \Xstate was
extended by several additional levels lying close to the atomic asymptote. In a
coupled channels fitting routine complete molecular potentials for both
electronic states were fitted. Along with the line frequencies of the molecular
transitions, recently published positions of Feshbach resonances in $^{40}$K
and $^{87}$Rb mixtures (F. Ferlaino et al. Phys. Rev. A 74, 039903 (2006)) were
included in the fit. This makes the derived potential curves capable for an
accurate description of observed cold collision features so far. Predictions of
scattering lengths and Feshbach resonances in other isotopic combinations are
reported.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:59:27 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Pashov",
"A.",
""
],
[
"Docenko",
"O.",
""
],
[
"Tamanis",
"M.",
""
],
[
"Ferber",
"R.",
""
],
[
"Knoeckel",
"H.",
""
],
[
"Tiemann",
"E.",
""
]
] |
0706.2850 | Chi-Tuong Pham | Chi-Tuong Pham (CFTC), Pedro Patr\'icio (CFTC, ISEL), Jose Manuel
Romero-Enrique (DFAMN) | Complete wetting transitions of nematic liquid crystals on a structured
substrate | null | null | null | null | cond-mat.other | null | In this article, we generalize Wenzel law, which assigns an effective contact
angle for a droplet on a rough substrate, when the wetting layer has an ordered
phase, like a nematic. We estimate the conditions for which the wetting
behavior of an ordered fluid can be qualitatively different from the one
usually found in a simple fluid. To particularize our general considerations,
we will use the Landau-de Gennes mean field approach to investigate
theoretically and numerically the complete wetting transition between a nematic
liquid crystal and a saw-shaped structured substrate.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 17:59:47 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Jun 2007 19:17:40 GMT"
}
] | 2007-06-24T00:00:00 | [
[
"Pham",
"Chi-Tuong",
"",
"CFTC"
],
[
"Patrício",
"Pedro",
"",
"CFTC, ISEL"
],
[
"Romero-Enrique",
"Jose Manuel",
"",
"DFAMN"
]
] |
0706.2851 | Giovanni Peccati | Domenico Marinucci (DIPMAT), Giovanni Peccati (LSTA) | Group Representations and High-Resolution Central Limit Theorems for
Subordinated Spherical Random Fields | Revised Version | Bernoulli, Volume 16, n. 3, pp. 798-824 (2010) | null | null | math.PR | null | We study the weak convergence (in the high-frequency limit) of the frequency
components associated with Gaussian-subordinated, spherical and isotropic
random fields. In particular, we provide conditions for asymptotic Gaussianity
and we establish a new connection with random walks on the the dual of SO(3),
which mirrors analogous results previously established for fields defined on
Abelian groups (see Marinucci and Peccati (2007)). Our work is motivated by
applications to cosmological data analysis, and specifically by the
probabilistic modelling and the statistical analysis of the Cosmic Microwave
Background radiation, which is currently at the frontier of physical research.
To obtain our main results, we prove several fine estimates involving
convolutions of the so-called Clebsch-Gordan coefficients (which are elements
of unitary matrices connecting reducible representations of SO(3)); this allows
to intepret most of our asymptotic conditions in terms of coupling of angular
momenta in a quantum mechanical system. Part of the proofs are based on
recently established criteria for the weak convergence of multiple Wiener-It\^o
integrals.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:01:03 GMT"
},
{
"version": "v2",
"created": "Wed, 20 Jun 2007 14:34:30 GMT"
},
{
"version": "v3",
"created": "Tue, 10 Jul 2007 12:51:27 GMT"
}
] | 2013-03-12T00:00:00 | [
[
"Marinucci",
"Domenico",
"",
"DIPMAT"
],
[
"Peccati",
"Giovanni",
"",
"LSTA"
]
] |
0706.2852 | Ben Weinkove | D.H. Phong, Jian Song, Jacob Sturm, Ben Weinkove | The K\"ahler-Ricci flow with positive bisectional curvature | 15 pages | Invent. Math. 173 (2008), no. 3, 651-665 | 10.1007/s00222-008-0134-x | null | math.DG | null | We show that the K\"ahler-Ricci flow on a manifold with positive first Chern
class converges to a K\"ahler-Einstein metric assuming positive bisectional
curvature and certain stability conditions.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:05:03 GMT"
}
] | 2018-12-20T00:00:00 | [
[
"Phong",
"D. H.",
""
],
[
"Song",
"Jian",
""
],
[
"Sturm",
"Jacob",
""
],
[
"Weinkove",
"Ben",
""
]
] |
0706.2853 | Colm Ryan | C.A. Ryan, O. Moussa, J. Baugh and R. Laflamme | A spin based heat engine: demonstration of multiple rounds of
algorithmic cooling | 6 pages, 4 figures, improved content due to referee critique | Phys. Rev. Lett. 100, 140401 (2008) | 10.1103/PhysRevLett.100.140501 | null | quant-ph | null | We show experimental results demonstrating multiple rounds of heat-bath
algorithmic cooling in a 3 qubit solid-state nuclear magnetic resonance quantum
information processor. By dynamically pumping entropy out of the system of
interest and into the heat-bath, we are able show purification of a single
qubit to a polarization 1.69 times that of the heat-bath and thus go beyond the
Shannon bound for closed system cooling. The cooling algorithm implemented
requires both high fidelity coherent control and a deliberate controlled
interaction with the environment. We discuss the improvements in control that
allowed this demonstration. This experimental work shows that given this level
of quantum control in systems with sufficiently large polarizations, nearly
pure qubits should be achievable.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:09:57 GMT"
},
{
"version": "v2",
"created": "Wed, 23 Apr 2008 18:23:05 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Ryan",
"C. A.",
""
],
[
"Moussa",
"O.",
""
],
[
"Baugh",
"J.",
""
],
[
"Laflamme",
"R.",
""
]
] |
0706.2854 | Jason Uhing ju | Jason Uhing | A Polynomial Invariant Of Twisted Graph Diagrams | 22 pages | null | null | null | math.GT math.CO | null | Twisted graph diagrams are virtual graph diagrams with bars on edges. A
bijection between abstract graph diagrams and twisted graph diagrams is
constructed. Then a polynomial invariant of Yamada-type is developed which
provides a lower bound for the virtual crossing number of virtual graph
diagrams.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:45:49 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Uhing",
"Jason",
""
]
] |
0706.2855 | Dmitry Sergeevich Petrov | D. S. Petrov, G. E. Astrakharchik, D. J. Papoular, C. Salomon, G. V.
Shlyapnikov | Crystalline phase of strongly interacting Fermi mixtures | 4 pages, 1 color figure, published version | Phys. Rev. Lett. 99, 130407 (2007) | 10.1103/PhysRevLett.99.130407 | NSF-KITP-07-132 | cond-mat.stat-mech | null | We show that the system of weakly bound molecules of heavy and light
fermionic atoms is characterized by a long-range intermolecular repulsion and
can undergo a gas-crystal quantum transition if the mass ratio exceeds a
critical value. For the critical mass ratio above 100 obtained in our
calculations, this crystalline order can be observed as a superlattice in an
optical lattice for heavy atoms with a small filling factor. We also find that
this novel system is sufficiently stable with respect to molecular relaxation
into deep bound states and to the process of trimer formation.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:26:18 GMT"
},
{
"version": "v2",
"created": "Thu, 4 Oct 2007 08:27:10 GMT"
}
] | 2007-10-04T00:00:00 | [
[
"Petrov",
"D. S.",
""
],
[
"Astrakharchik",
"G. E.",
""
],
[
"Papoular",
"D. J.",
""
],
[
"Salomon",
"C.",
""
],
[
"Shlyapnikov",
"G. V.",
""
]
] |
0706.2856 | Ana L. C. Pereira | Ana L. C. Pereira and P. A. Schulz | Valley polarization effects on the localization in graphene Landau
levels | 5 pages, 6 figures, extended version, with 2 new figures added | Phys. Rev. B 77, 075416 (2008) | 10.1103/PhysRevB.77.075416 | null | cond-mat.mes-hall cond-mat.dis-nn | null | Effects of disorder and valley polarization in graphene are investigated in
the quantum Hall regime. We find anomalous localization properties for the
lowest Landau level (LL), where disorder can induce wavefunction delocalization
(instead of localization), both for white-noise and gaussian-correlated
disorder. We quantitatively identify the contribution of each sublattice to
wavefunction amplitudes. Following the valley (sublattice) polarization of
states within LLs for increasing disorder we show: (i) valley mixing in the
lowest LL is the main effect behind the observed anomalous localization
properties, (ii) the polarization suppression with increasing disorder depends
on the localization for the white-noise model, while, (iii) the disorder
induces a partial polarization in the higher Landau levels for both disorder
models.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:23:08 GMT"
},
{
"version": "v2",
"created": "Sat, 17 Nov 2007 14:41:52 GMT"
}
] | 2008-02-21T00:00:00 | [
[
"Pereira",
"Ana L. C.",
""
],
[
"Schulz",
"P. A.",
""
]
] |
0706.2857 | Andrei Marshakov | A.Marshakov | On Microscopic Origin of Integrability in Seiberg-Witten Theory | 24 pages, 1 figure, LaTeX, based on the talks at 'Geometry and
Integrability in Mathematical Physics', Moscow, May 2006; 'Quarks-2006',
Repino, May 2006; Twente conference on Lie groups, December 2006 and
'Classical and Quantum Integrable Models', Dubna, January 2007 | Theor.Math.Phys.154:362-384,2008 | 10.1007/s11232-008-0033-8 | FIAN/TD-15/07, ITEP/TH-24/07 | hep-th | null | We discuss microscopic origin of integrability in Seiberg-Witten theory,
following mostly the results of hep-th/0612019, as well as present their
certain extension and consider several explicit examples. In particular, we
discuss in more detail the theory with the only switched on higher perturbation
in the ultraviolet, where extra explicit formulas are obtained using
bosonization and elliptic uniformization of the spectral curve.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:38:21 GMT"
},
{
"version": "v2",
"created": "Tue, 30 Oct 2007 02:24:06 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Marshakov",
"A.",
""
]
] |
0706.2858 | Florentin Smarandache | C. Dumitrescu, N. Virlan, St. Zamfir, E. Radescu, N. Radescu,
F.Smarandache | Smarandache Type Function Obtained by Duality | 15 pages, one figure | Studii si Cercetari Stiintifice, Seria: Matematica, University of
Bacau, No. 9, pp. 49-72, 1999 | null | null | math.GM | null | In this paper we extend the Smarandache function from the set $N*$ of
positive integers to the set $Q$ pf rational numbers. Using the inverse
formula, this function is also regarded as a generating function. We put in
evidence a procedure to construct a (numerical) function starting from a given
function in two particular cases. Also, connections between this function and
Euler totient function as well as with Riemann zeta function are established.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:51:15 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Dumitrescu",
"C.",
""
],
[
"Virlan",
"N.",
""
],
[
"Zamfir",
"St.",
""
],
[
"Radescu",
"E.",
""
],
[
"Radescu",
"N.",
""
],
[
"Smarandache",
"F.",
""
]
] |
0706.2859 | Beatriz Gato-Rivera | Beatriz Gato-Rivera | The Adapted Ordering Method for Lie Algebras and Superalgebras and their
Generalizations | Many improvements in the redaction for pedagogical purposes. Latex,
11 pages | J.Phys.A41:045201,2008 | 10.1088/1751-8113/41/4/045201 | IMAFF-FM-07-01, NIKHEF/2007-13 | hep-th math.RA math.RT | null | In 1998 the Adapted Ordering Method was developed for the representation
theory of the superconformal algebras in two dimensions. It allows: to
determine maximal dimensions for a given type of space of singular vectors, to
identify all singular vectors by only a few coefficients, to spot subsingular
vectors and to set the basis for constructing embedding diagrams. In this
article we present the Adapted Ordering Method for general Lie algebras and
superalgebras, and their generalizations, provided they can be triangulated. We
also review briefly the results obtained for the Virasoro algebra and for the
N=2 and Ramond N=1 superconformal algebras.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:52:53 GMT"
},
{
"version": "v2",
"created": "Sun, 24 Jun 2007 11:23:10 GMT"
},
{
"version": "v3",
"created": "Sat, 15 Dec 2007 14:55:12 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Gato-Rivera",
"Beatriz",
""
]
] |
0706.2860 | Elias Gyftopoulos | Elias P. Gyftopoulos | Comments on Violations of the Second Law | 2 pages, 1 figure | null | null | null | quant-ph | null | The authors of Ref. [1] claim to have experimental verification of violations
of the second law of thermodynamics based on the assertions: (i) "for large
systems and over long times the entropy production rate is necessarily
positive"; (ii) Loschmidt's paradox interpreted as indicating that entropy
production can be both positive and negative; (iii) and violations of the
second law for small systems over short time scales predicted by the
fluctuation theorem FT [2]. Neither the claim nor the assertions are correct.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:54:50 GMT"
}
] | 2007-06-20T00:00:00 | [
[
"Gyftopoulos",
"Elias P.",
""
]
] |
0706.2861 | Ofer Aharony | Ofer Aharony and Sean A. Hartnoll | A phase transition in commuting Gaussian multi-matrix models | 10 pages, 1 figure, latex. v3 (with a new title) corrects the wrong
assumption that the dominant phase in gauge theories on S^3 involves
commuting matrices, and the wrong conclusion that these theories have high
temperature phase transitions; we thank Shiraz Minwalla for pointing this out | null | null | NSF-KITP-07-142, WIS/08/07-JUNE-DPP, SLAC-PUB-12570 | hep-th | null | We analyze in detail a second order phase transition that occurs in large N
Gaussian multi-matrix models in which the matrices are constrained to be
commuting. The phase transition occurs as the relative masses of the matrices
are varied, assuming that there are at least four matrices in the lowest mass
level. We also discuss the phase structure of weakly coupled large N 3+1
dimensional gauge theories compactified on a three-sphere of radius R. We argue
that these theories are well described at high temperatures (T >> 1/R) by a
Gaussian multi-matrix model, and that they do not exhibit any phase transitions
between the deconfinement scale (T ~ 1/R) and the scale where perturbation
theory breaks down (T ~ 1 / \lambda R, where \lambda is the 't Hooft coupling).
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 18:55:41 GMT"
},
{
"version": "v2",
"created": "Mon, 25 Jun 2007 22:59:07 GMT"
},
{
"version": "v3",
"created": "Mon, 2 Jul 2007 17:31:46 GMT"
}
] | 2007-07-02T00:00:00 | [
[
"Aharony",
"Ofer",
""
],
[
"Hartnoll",
"Sean A.",
""
]
] |
0706.2862 | Patrick Huber | Patrick Huber, Walter Winter | Neutrino Factory Superbeam | 7 pages, 5 figures, 1 table | Phys.Lett.B655:251-256,2007 | 10.1016/j.physletb.2007.09.018 | null | hep-ph hep-ex | null | We discuss the optimization of a neutrino factory for large \sin^2 2
\theta_{13}, where we assume minimum effort on the accelerator side. This
implies that we use low muon energies for the price of an optimized detection
system. We demonstrate that such a neutrino factory performs excellent if
combined with the electron neutrino appearance channel. Instead of the platinum
channel operated with the muon neutrinos from the muon decays, we propose to
use the initial superbeam from the decaying pions and kaons, which might be
utilized at little extra effort. Since we assume out-of-phase bunches arriving
at the same detector, we do not require electron charge identification. In
addition, we can choose the proton energy such that we obtain a synergistic
spectrum peaking at lower energies. We find that both the superbeam and the
neutrino factory beam should used at the identical baseline to reduce matter
density uncertainties, possibly with the same detector. This effectively makes
the configuration a single experiment, which we call ``neutrino factory
superbeam''. We demonstrate that this experiment outperforms a low-energy
neutrino factory or a wide band beam alone beyond a simple addition of
statistics.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:00:13 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Huber",
"Patrick",
""
],
[
"Winter",
"Walter",
""
]
] |
0706.2863 | Chih-Hung Wang | Chih-Hung Wang | Charged Fluid Dynamics in Scalar-Tensor Theories of Gravity with Torsion | 4 pages | null | 10.1142/9789812834300_0129 | null | gr-qc | null | n scalar-tensor theories of gravity with torsion, the gravitational field is
described in terms of a symmetric metric tensor $g$, a metric-compatible
connection $\nabla$ with torsion, and a scalar field $\phi$. The main aim is to
explore an interaction of a charged perfect fluid and a scalar field $\phi$ in
a background electromagnetic and gravitational field described by \{$g$,
$\nabla$, $\phi$\}. The interaction is based on an action functional $S_C$ of a
charged perfect fluid that is invariant under global conformal rescalings.
Using a variational principle, we obtain equations of motion for the charged
perfect fluid. Moreover, we verify that these equations of motion are
equivalent to the gauge identities obtained from the invariance of an action
functional under spacetime dffeomorphisms and a local U(1) gauge group.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:00:37 GMT"
}
] | 2016-11-15T00:00:00 | [
[
"Wang",
"Chih-Hung",
""
]
] |
0706.2864 | Pasquale Dario Serpico | A. Cuoco, G. Miele, P. D. Serpico | Astrophysical interpretation of the medium scale clustering in the
ultra-high energy sky | 10 pages, 7 figures; one reference added | Phys.Lett.B660:307-314,2008 | 10.1016/j.physletb.2007.12.054 | DSF/20/2007, FERMILAB-PUB-07-212-A, IFIC-07-30 | astro-ph hep-ph | null | We compare the clustering properties of the combined dataset of ultra-high
energy cosmic rays events, reported by the AGASA, HiRes, Yakutsk and Sugar
collaborations, with a catalogue of galaxies of the local universe (redshift
z<~0.06). We find that the data reproduce particularly well the clustering
properties of the nearby universe within z <~0.02. There is no statistically
significant cross-correlation between data and structures, although
intriguingly the nominal cross-correlation chance probability drops from ~50%
to ~10% using the catalogue with a smaller horizon. Also, we discuss the impact
on the robustness of the results of deflections in some galactic magnetic field
models used in the literature. These results suggest a relevant role of
magnetic fields (possibly extragalactic ones, too) and/or possibly some heavy
nuclei fraction in the UHECRs. The importance of a confirmation of these hints
by Auger data is emphasized.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:05:14 GMT"
},
{
"version": "v2",
"created": "Tue, 12 Feb 2008 11:28:13 GMT"
},
{
"version": "v3",
"created": "Wed, 13 Feb 2008 22:37:42 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cuoco",
"A.",
""
],
[
"Miele",
"G.",
""
],
[
"Serpico",
"P. D.",
""
]
] |
0706.2865 | Annika Peter | Annika H. G. Peter (Princeton), Alice E. Shapley (Princeton), David R.
Law (Caltech), Charles C. Steidel (Caltech), Dawn K. Erb (CfA), Naveen A.
Reddy (NOAO), Max Pettini (IoA) | Morphologies of Galaxies in and around a Protocluster at z=2.300 | 25 pages including 16 figures. Accepted for publication in ApJ.
Version with full resolution figures available at
http://www.astro.princeton.edu/~apeter/LBG/papers/peter2007_fullres.ps.gz | null | 10.1086/521184 | null | astro-ph | null | We present results from the first robust investigation of galaxy morphology
as a function of environment at z>1.5. Our study is motivated by the fact that
star-forming galaxies contained within a protocluster at z=2.3 in the HS1700+64
field have significantly older ages and larger stellar masses on average than
those at similar redshifts but more typical environmental densities. In the
analysis of HST/ACS images, we apply non-parametric statistics to characterize
the rest-frame UV morphologies of a sample of 85 UV-selected star-forming
galaxies at z=1.7-2.9, 22 of which are contained in the protocluster. The
remaining 63 control-sample galaxies are not in the protocluster but have a
similar mean redshift of <z>~2.3. We find no environmental dependence for the
distributions of morphological properties. Combining the measured morphologies
with the results of population synthesis modeling, we find only weak
correlations, if any, between morphological and stellar population properties
such as stellar mass, age, extinction and star-formation rate. Given the
incomplete census of the protocluster galaxy population, and the lack of
correlation between rest-frame UV morphology and star-formation history at z~2
within our sample, the absence of environmental trends in the distribution of
morphological properties is not surprising. Additionally, using a larger sample
of photometric candidates, we compare morphological distributions for 282
UV-selected and 43 near-IR-selected galaxies. While the difference in the
degree of nebulosity between the two samples appears to be a byproduct of the
fainter average rest-frame UV surface brightness of the near-IR-selected
galaxies, we find that, among the lowest surface brightness galaxies, the
near-IR-selected objects have significantly smaller angular sizes (abridged).
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:09:59 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Peter",
"Annika H. G.",
"",
"Princeton"
],
[
"Shapley",
"Alice E.",
"",
"Princeton"
],
[
"Law",
"David R.",
"",
"Caltech"
],
[
"Steidel",
"Charles C.",
"",
"Caltech"
],
[
"Erb",
"Dawn K.",
"",
"CfA"
],
[
"Reddy",
"Naveen A.",
"",
"NOAO"
],
[
"Pettini",
"Max",
"",
"IoA"
]
] |
0706.2866 | Creighton Thomas | Creighton K. Thomas, A. Alan Middleton | Matching Kasteleyn Cities for Spin Glass Ground States | 4 pages, 2 figures; minor clarifications | Physical Review B 76, 220406(R) (2007) | 10.1103/PhysRevB.76.220406 | null | cond-mat.dis-nn cond-mat.stat-mech | null | As spin glass materials have extremely slow dynamics, devious numerical
methods are needed to study low-temperature states. A simple and fast
optimization version of the classical Kasteleyn treatment of the Ising model is
described and applied to two-dimensional Ising spin glasses. The algorithm
combines the Pfaffian and matching approaches to directly strip droplet
excitations from an excited state. Extended ground states in Ising spin glasses
on a torus, which are optimized over all boundary conditions, are used to
compute precise values for ground state energy densities.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:22:29 GMT"
},
{
"version": "v2",
"created": "Fri, 22 Jun 2007 02:22:22 GMT"
},
{
"version": "v3",
"created": "Thu, 28 Jun 2007 21:53:43 GMT"
},
{
"version": "v4",
"created": "Tue, 20 Nov 2007 18:49:15 GMT"
}
] | 2008-02-28T00:00:00 | [
[
"Thomas",
"Creighton K.",
""
],
[
"Middleton",
"A. Alan",
""
]
] |
0706.2867 | Kaushik Majumdar | Kaushik Majumdar | Outline of a novel architecture for cortical computation | 21 pages, four figures | null | 10.1007/s11571-007-9034-9 | null | q-bio.NC q-bio.QM | null | In this paper a novel architecture for cortical computation has been
proposed. This architecture is composed of computing paths consisting of
neurons and synapses only. These paths have been decomposed into lateral,
longitudinal and vertical components. Cortical computation has then been
decomposed into lateral computation (LaC), longitudinal computation (LoC) and
vertical computation (VeC). It has been shown that various loop structures in
the cortical circuit play important roles in cortical computation as well as in
memory storage and retrieval, keeping in conformity with the molecular basis of
short and long term memory. A new learning scheme for the brain has also been
proposed and how it is implemented within the proposed architecture has been
explained. A number of mathematical results about the architecture have been
proposed, many of which without proof.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:13:09 GMT"
},
{
"version": "v2",
"created": "Wed, 12 Dec 2007 10:55:48 GMT"
}
] | 2007-12-12T00:00:00 | [
[
"Majumdar",
"Kaushik",
""
]
] |
0706.2868 | Michael Shulman | Michael Shulman | Comparing composites of left and right derived functors | 44 pages; expanded with detailed examples added; final version
published in NYJM | New York Journal of Mathematics 17 (2011), 75-125 | null | null | math.CT math.AT | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We introduce a new categorical framework for studying derived functors, and
in particular for comparing composites of left and right derived functors. Our
central observation is that model categories are the objects of a double
category whose vertical and horizontal arrows are left and right Quillen
functors, respectively, and that passage to derived functors is functorial at
the level of this double category. The theory of conjunctions and mates in
double categories, which generalizes the theory of adjunctions and mates in
2-categories, then gives us canonical ways to compare composites of left and
right derived functors. We give a number of sample applications, most of which
are improvements of existing proofs in the literature.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:18:05 GMT"
},
{
"version": "v2",
"created": "Sat, 26 Feb 2011 03:13:35 GMT"
}
] | 2011-03-01T00:00:00 | [
[
"Shulman",
"Michael",
""
]
] |
0706.2869 | Israel Klich | I. Klich, C. Lannert, G. Refael | Supercurrent survival under Rosen-Zener quench of hard core bosons | null | Phys. Rev. Lett. 99, 205303 (2007) | 10.1103/PhysRevLett.99.205303 | null | cond-mat.other quant-ph | null | We study the survival of super-currents in a system of impenetrable bosons
subject to a quantum quench from its critical superfluid phase to an insulating
phase. We show that the evolution of the current when the quench follows a
Rosen-Zener profile is exactly solvable. This allows us to analyze a quench of
arbitrary rate, from a sudden destruction of the superfluid to a slow opening
of a gap. The decay and oscillations of the current are analytically derived,
and studied numerically along with the momentum distribution after the quench.
In the case of small supercurrent boosts $\nu$, we find that the current
surviving at long times is proportional to $\nu^3$.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:50:18 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Klich",
"I.",
""
],
[
"Lannert",
"C.",
""
],
[
"Refael",
"G.",
""
]
] |
0706.2870 | Hojeong Kim | The BABAR Collaboration, B. Aubert, et al | Search for the Decays B0->e+e-gamma and B0->mu+mu-gamma | 7 pages, 6 figures, submitted to Phys. Rev. Lett | Phys.Rev.D77:011104,2008 | 10.1103/PhysRevD.77.011104 | SLAC-PUB-12594 | hep-ex | null | We present results of a search for the decays $B^0 \to \ell^+\ell^-\gamma$
($\ell=e$, $\mu$). The search is performed using $320\times 10^{6}$ $B\bar{B}$
pairs collected at the $\Upsilon(4S)$ resonance with the BABAR detector at the
PEP-II $B$ Factory at SLAC. We find no significant signal and set the following
branching fraction upper limits at the 90% confidence level:
$\mathcal{B}(B^0\to e^+e^-\gamma)<1.2\times 10^{-7}$ and $\mathcal{B}(B^0\to
\mu^+\mu^-\gamma)<1.5\times 10^{-7}$.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:21:46 GMT"
}
] | 2010-04-12T00:00:00 | [
[
"The BABAR Collaboration",
"",
""
],
[
"Aubert",
"B.",
""
]
] |
0706.2871 | Kiwoon Choi | Won Sang Cho and Kiwoon Choi | Probing the Messenger of SUSY Breaking with Gaugino Masses | 11 pages, To appear at the Proceedings of International Workshop on
Theoretical High Energy Physics, March 2007, Roorkee, India | AIPConf.Proc.939:219-226,2007 | 10.1063/1.2803808 | null | hep-ph | null | Gaugino masses might provide useful information on the underlying scheme of
supersymmetry breaking as they are least dependent on the unknown physics
between the TeV scale and the high messenger scale of supersymmetry breaking.
We discuss the pattern of low energy gaugino masses in various schemes of
supersymmetry breaking together with the possibility to determine the gaugino
masses at LHC.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:22:48 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Cho",
"Won Sang",
""
],
[
"Choi",
"Kiwoon",
""
]
] |
0706.2872 | Vitor Pereira | Vitor M. Pereira, Johan Nilsson, A. H. Castro Neto | The Coulomb impurity problem in graphene | 3 Figures; minor typo corrections and minor update in Fig. 3d | Phys. Rev. Lett. 99, 166802 (2007) | 10.1103/PhysRevLett.99.166802 | null | cond-mat.str-el cond-mat.mes-hall | null | We address the problem of an unscreened Coulomb charge in graphene, and
calculate the local density of states and displaced charge as a function of
energy and distance from the impurity. This is done non-perturbatively in two
different ways: (1) solving the problem exactly by studying numerically the
tight-binding model on the lattice; (2) using the continuum description in
terms of the 2D Dirac equation. We show that the Dirac equation, when properly
regularized, provides a qualitative and quantitative low energy description of
the problem. The lattice solution shows extra features that cannot be described
by the Dirac equation, namely bound state formation and strong renormalization
of the van Hove singularities.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:27:16 GMT"
},
{
"version": "v2",
"created": "Wed, 27 Jun 2007 19:11:45 GMT"
}
] | 2007-10-17T00:00:00 | [
[
"Pereira",
"Vitor M.",
""
],
[
"Nilsson",
"Johan",
""
],
[
"Neto",
"A. H. Castro",
""
]
] |
0706.2873 | Petr Horava | Eric G. Gimon, Petr Horava | Astrophysical Violations of the Kerr Bound as a Possible Signature of
String Theory | 4 pages | Phys.Lett.B672:299-302,2009 | 10.1016/j.physletb.2009.01.026 | null | hep-th astro-ph hep-ph | null | In 4D general relativity, the angular momentum of a black hole is limited by
the Kerr bound. We suggest that in string theory, this bound can be breached
and compact black-hole-like objects can spin faster. Near such "superspinars,"
the efficiency of energy transfer from the accreting matter to radiation can
reach 100%, compared to the maximum efficiency of 42% of the extremal Kerr (or
6% of the Schwarzschild) black hole. Finding such superspinning objects as
active galactic nuclei, GBHCs, or sources of gamma ray bursts, could be viewed
as experimental support for string theory.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:31:11 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Gimon",
"Eric G.",
""
],
[
"Horava",
"Petr",
""
]
] |
0706.2874 | Michael Shulman | Michael A. Shulman | Parametrized spaces model locally constant homotopy sheaves | 26 pages; exposition improved | Topology Appl. 155 (2008), no. 5, 412--432. | 10.1016/j.topol.2007.11.001 | null | math.AT | null | We prove that the homotopy theory of parametrized spaces embeds fully and
faithfully in the homotopy theory of simplicial presheaves, and that its
essential image consists of the locally homotopically constant objects. This
gives a homotopy-theoretic version of the classical identification of covering
spaces with locally constant sheaves. We also prove a new version of the
classical result that spaces parametrized over X are equivalent to spaces with
an action of the loop space of X. This gives a homotopy-theoretic version of
the correspondence between covering spaces over X and sets with an action of
the fundamental group of X. We then use these two equivalences to study base
change functors for parametrized spaces.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:31:12 GMT"
},
{
"version": "v2",
"created": "Wed, 7 Nov 2007 21:11:57 GMT"
}
] | 2010-03-15T00:00:00 | [
[
"Shulman",
"Michael A.",
""
]
] |
0706.2875 | Mladen Georgiev | Mladen Georgiev | Nonradiative DKR processes: revisiting the theory. IV. On the
controversy over a polaron state bound to an F center in alkali halides | 8 pages including 2 figures, all pdf format | null | null | null | cond-mat.mtrl-sci | null | We are commenting on an earlier hypothesis of polaron states bound to F
centers in alkali halides. These states increasing the effective size of the
color centers, they play an active role in concentration-dependent phenomena,
such as the observed quenching of F center luminescence. Our record shows only
one related study on NaBr and NaI which has also been aimed at checking the
bound polaron hypothesis. Further studies of the concentration quenching in
other alkali halide hosts whould eventually shine more light on the problem.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:31:59 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Georgiev",
"Mladen",
""
]
] |
0706.2876 | Alexander Olshevsky | Alex Olshevsky, John N. Tsitsiklis | On the Nonexistence of Quadratic Lyapunov Functions for Consensus
Algorithms | null | null | null | null | math.OC | null | We provide an example proving that there exists no quadratic Lyapunov
function for a certain class of linear agreement/consensus algorithms, a fact
that had been numerically verified in [5]. We also briefly discuss sufficient
conditions for the existence of such a Lyapunov function.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:36:43 GMT"
},
{
"version": "v2",
"created": "Sat, 8 Mar 2008 00:58:54 GMT"
}
] | 2008-03-08T00:00:00 | [
[
"Olshevsky",
"Alex",
""
],
[
"Tsitsiklis",
"John N.",
""
]
] |
0706.2877 | Alessandro Fedrizzi | Alessandro Fedrizzi, Thomas Herbst, Andreas Poppe, Thomas Jennewein,
Anton Zeilinger | A wavelength-tunable fiber-coupled source of narrowband entangled
photons | 10 pages, 5 figures. Article rewritten, added Fig.(1a-1b). Published
in Optics Express, comments welcome | Opt. Express 15, 15377-15386 (2007) | 10.1364/OE.15.015377 | null | quant-ph | null | We demonstrate a wavelength-tunable, fiber-coupled source of
polarization-entangled photons with extremely high spectral brightness and
quality of entanglement. Using a 25 mm PPKTP crystal inside a polarization
Sagnac interferometer we detect a spectral brightness of 273000 pairs/(s mW
nm), a factor of 28 better than comparable previous sources while state
tomography showed the two-photon state to have a tangle of T=0.987. This
improvement was achieved by use of a long crystal, careful selection of
focusing parameters and single-mode fiber coupling. We demonstrate that, due to
the particular geometry of the setup, the signal and idler wavelengths can be
tuned over a wide range without loss of entanglement.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:43:28 GMT"
},
{
"version": "v2",
"created": "Mon, 5 Nov 2007 18:13:51 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Fedrizzi",
"Alessandro",
""
],
[
"Herbst",
"Thomas",
""
],
[
"Poppe",
"Andreas",
""
],
[
"Jennewein",
"Thomas",
""
],
[
"Zeilinger",
"Anton",
""
]
] |
0706.2878 | Roman Werpachowski | Roman Werpachowski | On the solutions of generalized discrete Poisson equation | 8 pages, LaTeX | Linear Algebra and its Applications, 430 (2007), 8 | null | null | math-ph math.MP | null | The set of common numerical and analytical problems is introduced in the form
of the generalized multidimensional discrete Poisson equation. It is shown that
its solutions with square-summable discrete derivatives are unique up to a
constant. The proof uses the Fourier transform as the main tool. The necessary
condition for the existence of the solution is provided.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 20:43:48 GMT"
}
] | 2011-09-27T00:00:00 | [
[
"Werpachowski",
"Roman",
""
]
] |
0706.2879 | Jan Robrade | J. Robrade, J.H.M.M. Schmitt | X-rays from RU Lupi - Accretion and winds in CTTS | accepted by A&A, 10 pages | null | 10.1051/0004-6361:20077644 | null | astro-ph | null | Using three XMM-Newton observations we study the X-ray emission of RU Lup, a
accreting and wind-driving CTTS. In comparison with other bright CTTS we study
possible signatures of accretion and winds in their X-ray emission. Results: We
find three levels of activity among the observations of RU Lup, clearly of
magnetic origin due to the corresponding high plasma temperatures. Density
analysis with the OVII triplet indicates high densities in the cool plasma,
suggesting accretion shocks to be a significant contributor to the soft X-ray
emission. No strong overall metal depletion is observed. Excess emission at 6.4
keV during the more active phase suggest the presence of iron fluorescence. In
accreting stars we find an excess of cool plasma as evidenced by lower
OVIII/OVII line ratios compared to main-sequence stars. High density plasma
appears to be only present in low-mass CTTS, while accreting stars with
intermediate masses (> 2 M_Sun) have lower densities. Conclusions: In all
investigated CTTS the characteristics of the cooler X-ray emitting plasma are
influenced by the accretion process. We suspect different accretion rates and
amount of funneling, possibly linked to stellar mass and radius, to be mainly
responsible for the different properties of their cool plasma component. The
exceptional strong X-ray absorption in RU Lup and other CTTS is probably
related to accretion flows and an optically transparent wind emanating from the
star or the disk.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 14:41:13 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Robrade",
"J.",
""
],
[
"Schmitt",
"J. H. M. M.",
""
]
] |
0706.2880 | Jordan Bell | Leonhard Euler | A general method for investigating the roots of all equations by
approximation | 7 pages | null | null | null | math.HO math.CA math.NA | null | Translation of the Latin original, "Methodus generalis investigandi radices
omnium aequationum per approximationem" (1776). E643 in the Enestrom index.
Euler gives a series to find powers of roots of polynomials.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 21:21:00 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Euler",
"Leonhard",
""
]
] |
0706.2881 | Ehud Nakar | Ehud Nakar, Milos Milosavljevic and Daisuke Nagai | Cluster Merger Shock Constraints on Particle Acceleration and Nonthermal
Pressure in the Intracluster Medium | 10 pages, 4 figures, comments welcome | Astrophys.J 675:126-135, 2008 | 10.1086/526409 | null | astro-ph | null | X-ray observations of galaxy cluster merger shocks can be used to constrain
nonthermal processes in the intracluster medium (ICM). The presence of
nonthermal pressure components in the ICM, as well as the shock acceleration of
particles and their escape, all affect shock jump conditions in distinct ways.
Therefore, these processes can be constrained using X-ray surface brightness
and temperature maps of merger shock fronts. Here we use these observations to
place constraints on particle acceleration efficiency in intermediate Mach
number (M ~ 2-3) shocks and explore the potential to constrain the contribution
of nonthermal components (e.g., cosmic rays, magnetic field, and turbulence) to
ICM pressure in cluster outskirts. We model the hydrodynamic jump conditions in
merger shocks discovered in the galaxy clusters A520 (M ~ 2) and 1E 0657-56 (M
~ 3) using a multifluid model comprised of a thermal plasma, a nonthermal
plasma, and a magnetic field. Based on the published X-ray spectroscopic data
alone, we find that the fractional contribution of cosmic rays accelerated in
these shocks is lower than about 10% of the shock downstream pressure. Current
observations do not constrain the fractional contribution of nonthermal
components to the pressure of the undisturbed shock upstream. Future X-ray
observations, however, have the potential to either detect particle
acceleration in these shocks through its effect on the shock dynamics, or to
place a lower limit on the nonthermal pressure contributions in the undisturbed
ICM. We briefly discuss implications for models of particle acceleration in
collisionless shocks and the estimates of galaxy cluster masses derived from
X-ray and Sunyaev-Zel'dovich effect observations.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 21:48:04 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Nakar",
"Ehud",
""
],
[
"Milosavljevic",
"Milos",
""
],
[
"Nagai",
"Daisuke",
""
]
] |
0706.2882 | Jeff E. Sonier | J.E. Sonier, S.A. Sabok-Sayr, F.D. Callaghan, C.V. Kaiser, V.
Pacradouni, J.H. Brewer, S.L. Stubbs, W.N. Hardy, D.A. Bonn, R. Liang, W.A.
Atkinson | Hole doping dependences of the magnetic penetration depth and vortex
core size in YBa2Cu3Oy: Evidence for stripe correlations near 1/8 hole doping | 12 pages, 13 figures | Phys. Rev. B 76, 134518 (2007) | 10.1103/PhysRevB.76.134518 | null | cond-mat.supr-con | null | We report on muon spin rotation measurements of the internal magnetic field
distribution n(B) in the vortex solid phase of YBa2Cu3Oy (YBCO) single
crystals, from which we have simultaneously determined the hole doping
dependences of the in-plane Ginzburg-Landau (GL) length scales in the
underdoped regime. We find that Tc has a sublinear dependence on
1/lambda_{ab}^2, where lambda_{ab} is the in-plane magnetic penetration depth
in the extrapolated limits T -> 0 and H -> 0. The power coefficient of the
sublinear dependence is close to that determined in severely underdoped YBCO
thin films, indicating that the same relationship between Tc and the superfluid
density is maintained throughout the underdoped regime. The in-plane GL
coherence length (vortex core size) is found to increase with decreasing hole
doping concentration, and exhibit a field dependence that is explained by
proximity-induced superconductivity on the CuO chains. Both the magnetic
penetration depth and the vortex core size are enhanced near 1/8 hole doping,
supporting the belief by some that stripe correlations are a universal property
of high-Tc cuprates.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 22:01:18 GMT"
}
] | 2010-12-06T00:00:00 | [
[
"Sonier",
"J. E.",
""
],
[
"Sabok-Sayr",
"S. A.",
""
],
[
"Callaghan",
"F. D.",
""
],
[
"Kaiser",
"C. V.",
""
],
[
"Pacradouni",
"V.",
""
],
[
"Brewer",
"J. H.",
""
],
[
"Stubbs",
"S. L.",
""
],
[
"Hardy",
"W. N.",
""
],
[
"Bonn",
"D. A.",
""
],
[
"Liang",
"R.",
""
],
[
"Atkinson",
"W. A.",
""
]
] |
0706.2883 | Andreas Fuhrer | S. Roddaro, A. Fuhrer, C. Fasth, L. Samuelson, J. Xiang and C. M.
Lieber | Strong g-Factor Anisotropy in Hole Quantum Dots Defined in Ge/Si
Nanowires | 5 pages, 3 figures | null | null | null | cond-mat.mes-hall | null | We demonstrate fully tunable single and double quantum dots in a
one-dimensional hole system based on undoped Ge/Si core-shell nanowire
heterostructures. The local hole density along the nanowire is controlled by
applying voltages to five top gate electrodes with a periodicity of 80 nm,
insulated from the wire by a 20 nm-thick HfO_2 dielectric film. Low-temperature
transport measurements were used to investigate the magnetic field dependence
of Coulomb blockade peaks in a single quantum dot and indicate a strongly
anisotropic g-factor with |g_para| = 0.60 +/- 0.03 and |g_perp| < 0.12.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 23:06:31 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Roddaro",
"S.",
""
],
[
"Fuhrer",
"A.",
""
],
[
"Fasth",
"C.",
""
],
[
"Samuelson",
"L.",
""
],
[
"Xiang",
"J.",
""
],
[
"Lieber",
"C. M.",
""
]
] |
0706.2884 | Alex Levchenko | Alex Levchenko, Alex Kamenev | Keldysh Ginzburg-Landau action of fluctuating superconductors | 16 pages, 2 figures | Phys. Rev. B 76, 094518 (2007) | 10.1103/PhysRevB.76.094518 | null | cond-mat.supr-con | null | We derive Ginzburg-Landau action by systematically integrating out electronic
degrees of freedom in the framework of the Keldysh nonlinear sigma-model of
disordered superconductors. The resulting Ginzburg-Landau functional contains a
nonlocal $\Delta$-dependent contribution to the diffusion constant, which
leads, for example, to Maki-Thompson corrections. It also exhibits an anomalous
Gor'kov-Eliashberg coupling between $\Delta$ and the scalar potential, as well
as a peculiar nonlocal nonlinear term. The action is gauge invariant and
satisfies the fluctuation dissipation theorem. It may be employed e.g. for
calculation of higher moments of the current fluctuations.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 22:31:03 GMT"
},
{
"version": "v2",
"created": "Mon, 24 Sep 2007 22:05:08 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Levchenko",
"Alex",
""
],
[
"Kamenev",
"Alex",
""
]
] |
0706.2885 | David Schuster | David Schuster | An Alternative Explanation for Cosmological Redshift | null | null | null | null | physics.gen-ph | null | The first and most compelling evidence of the universe's expansion was, and
continues to be, the observed redshift of spectra from distant objects. This
paper plays "devil's advocate" by providing an alternative explanation with
elementary physics. I assume a steady-state universe that is infinite in both
expanse and age, with the observed redshifts caused by particle interactions
creating an overall index of refraction of the universe. The cumulative effects
of these interactions over long distances cause not only the shifts that we
observe, but also the monotonically increasing redshifts as more distant
objects are observed. This is a novel explanation for the phenomenon known as
"tired light" which has been discussed for decades.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 22:34:40 GMT"
},
{
"version": "v2",
"created": "Fri, 9 May 2008 23:11:50 GMT"
}
] | 2008-05-10T00:00:00 | [
[
"Schuster",
"David",
""
]
] |
0706.2886 | Junwei Zhao | Junwei Zhao | Time-Distance Imaging of Solar Far-Side Active Regions | 13 pages, 5 figures, accepted by ApJ Letters | null | 10.1086/520837 | null | astro-ph | null | It is of great importance to monitor large solar active regions in the
far-side of the Sun for space weather forecast, in particular, to predict their
appearance before they rotate into our view from the solar east limb. Local
helioseismology techniques, including helioseismic holography and
time-distance, have successfully imaged solar far-side active regions. In this
Letter, we further explore the possibility of imaging and improving the image
quality of solar far-side active regions by use of time-distance
helioseismology. In addition to the previously used scheme with four acoustic
signal skips, a five-skip scheme is also included in this newly developed
technique. The combination of both four- and five-skip far-side images
significantly enhances the signal-to-noise ratio in the far-side images, and
reduces spurious signals. The accuracy of the far-side active region imaging is
also assessed using one whole year solar observation.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 22:55:48 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Zhao",
"Junwei",
""
]
] |
0706.2887 | Eugene B. Kolomeisky | Eugene B. Kolomeisky, Joseph P. Straley, and Michael Timmins | Casimir effect in a one-dimensional gas of free fermions | 13 pages, 5 figures. A generalization to the case of an arbitrary
harmonic liquid is given and discussion is improved. Version to be published
in Phys. Rev. A | Phys.Rev.A78:022104,2008 | 10.1103/PhysRevA.78.022104 | null | cond-mat.mes-hall hep-th quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We compute an analog Casimir effect in a one-dimensional spinless Luttinger
liquid confined to a segment in the presence of a nearly-impenetrable partition
dividing the segment into two compartments. The Casimir interaction is found to
be a bounded piecewise-continuous oscillatory function whose maxima are points
of force discontinuity and correspond to resonant tunneling across the
partition. The well-known regularization-based results are reproduced by the
lower envelope of this function, which corresponds to an approximation that
ignores the rather large oscillations due to particle discreteness. These
macroscopic conclusions are tested and confirmed via a rigorous analysis of the
Casimir effect in an exactly-solvable model of a one-dimensional
non-relativistic spinless gas of free fermions, thus resolving an objection
that has been raised by Volovik (2003).
Additionally we confirm the result of a recent calculation which employed an
effective low-energy theory with a cutoff to find the Casimir interaction
between two strong well-separated impurities placed in a Luttinger liquid.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 19:13:49 GMT"
},
{
"version": "v2",
"created": "Fri, 18 Jul 2008 17:41:44 GMT"
}
] | 2014-11-18T00:00:00 | [
[
"Kolomeisky",
"Eugene B.",
""
],
[
"Straley",
"Joseph P.",
""
],
[
"Timmins",
"Michael",
""
]
] |
0706.2888 | James Harold Thomas | James Harold Thomas | Variations on Kak's Three Stage Quantum Cryptography Protocol | null | null | null | null | cs.CR | null | This paper introduces a variation on Kak's three-stage quanutm key
distribution protocol which allows for defence against the man in the middle
attack. In addition, we introduce a new protocol, which also offers similar
resiliance against such an attack.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 23:04:18 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Thomas",
"James Harold",
""
]
] |
0706.2889 | Sergio Dasso Dr. | S. Dasso, M. S. Nakwacki, P. D\'emoulin, C. H. Mandrini | Progressive transformation of a flux rope to an ICME | Solar Physics (in press) | null | 10.1007/s11207-007-9034-2 | null | astro-ph | null | The solar wind conditions at one astronomical unit (AU) can be strongly
disturbed by the interplanetary coronal mass ejections (ICMEs). A subset,
called magnetic clouds (MCs), is formed by twisted flux ropes that transport an
important amount of magnetic flux and helicity which is released in CMEs. At 1
AU from the Sun, the magnetic structure of MCs is generally modeled neglecting
their expansion during the spacecraft crossing. However, in some cases, MCs
present a significant expansion. We present here an analysis of the huge and
significantly expanding MC observed by the Wind spacecraft during 9 and 10
November, 2004. After determining an approximated orientation for the flux rope
using the minimum variance method, we precise the orientation of the cloud axis
relating its front and rear magnetic discontinuities using a direct method.
This method takes into account the conservation of the azimuthal magnetic flux
between the in- and out-bound branches, and is valid for a finite impact
parameter (i.e., not necessarily a small distance between the spacecraft
trajectory and the cloud axis). Moreover, using the direct method, we find that
the ICME is formed by a flux rope (MC) followed by an extended coherent
magnetic region. These observations are interpreted considering the existence
of a previous larger flux rope, which partially reconnected with its
environment in the front. These findings imply that the ejected flux rope is
progressively peeled by reconnection and transformed to the observed ICME (with
a remnant flux rope in the front part).
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 23:08:34 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Dasso",
"S.",
""
],
[
"Nakwacki",
"M. S.",
""
],
[
"Démoulin",
"P.",
""
],
[
"Mandrini",
"C. H.",
""
]
] |
0706.2890 | Keiichi Wada | Keiichi Wada (National Astronomical Observatory of Japan) | Origin of Warm High-Velocity Dense Gas in ULIRGs | 14 pages, 6 figures. Publications of Astronomical Society of Japan in
press | null | 10.1093/pasj/59.4.711 | null | astro-ph | null | Possible origins of the molecular absorption discovered in some ULIRGs are
investigated, based on a 3-D hydrodynamic model of star-forming interstellar
gas in a galactic central region. The blue-shifted, warm ($\sim 200-300$ K),
dense ($>10^6$ cm$^{-3}$) molecular gas suggested by CO absorption in IRAS
08752+3915 could be caused by the innermost region of the inhomogeneous
inter-stellar medium (ISM) around a supermassive black hole. The infrequent
observations of the dense gas with absorption in ULIRGs and Seyfert 2 galaxies
could simply suggest that the high-density regions occupy only a very small
volume fraction of the obscuring material. This is naturally expected if the
inhomogeneous structure of the ISM is caused by non-linear development of
instabilities. The model predicts a turbulent velocity field in the obscuring
material, therefore blue- and red-shifted gases should be observable with
nearly the same probability for the large enough statistical samples.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 23:14:21 GMT"
}
] | 2015-05-13T00:00:00 | [
[
"Wada",
"Keiichi",
"",
"National Astronomical Observatory of Japan"
]
] |
0706.2891 | Steven Willison | F. Canfora, A. Giacomini, S. Willison | Some exact solutions with torsion in 5-D Einstein-Gauss-Bonnet gravity | 19 pages, LaTex, no figures. References added, notation clarified.
Accepted for publication on Physical Review D | Phys.Rev.D76:044021,2007 | 10.1103/PhysRevD.76.044021 | CECS-PHY-07/11 | gr-qc hep-th | null | Exact solutions with torsion in Einstein-Gauss-Bonnet gravity are derived.
These solutions have a cross product structure of two constant curvature
manifolds. The equations of motion give a relation for the coupling constants
of the theory in order to have solutions with nontrivial torsion. This relation
is not the Chern-Simons combination. One of the solutions has a $AdS_2\times
S^3$ structure and is so the purely gravitational analogue of the
Bertotti-Robinson space-time where the torsion can be seen as the dual of the
covariantly constant electromagnetic field.
| [
{
"version": "v1",
"created": "Tue, 19 Jun 2007 23:37:33 GMT"
},
{
"version": "v2",
"created": "Tue, 10 Jul 2007 16:06:57 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Canfora",
"F.",
""
],
[
"Giacomini",
"A.",
""
],
[
"Willison",
"S.",
""
]
] |
0706.2892 | Sidney Redner | M. Mobilia, A. Petersen, S. Redner | On the Role of Zealotry in the Voter Model | 9 pages, 7 figures, 2-column revtex4 format. Revision has a figure
added and minor changes in response to referee comments. For publication in
JSTAT | J. Stat. Mech. P08029, (2007) | 10.1088/1742-5468/2007/08/P08029 | LMU 40/07 | physics.soc-ph cond-mat.stat-mech physics.gen-ph | null | We study the voter model with a finite density of zealots--voters than never
change opinion. For equal numbers of zealots of each species, the distribution
of magnetization (opinions) is Gaussian in the mean-field limit as well as in
one and two dimensions, with a width that is proportional to 1/sqrt{Z}, where Z
is the number of zealots, independent of the total number of voters. Thus just
a few zealots can prevent consensus or even the formation of a robust majority.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 15:35:48 GMT"
},
{
"version": "v2",
"created": "Thu, 2 Aug 2007 20:21:27 GMT"
}
] | 2007-08-23T00:00:00 | [
[
"Mobilia",
"M.",
""
],
[
"Petersen",
"A.",
""
],
[
"Redner",
"S.",
""
]
] |
0706.2893 | Greg Sepesi | Greg Sepesi | Dualheap Sort Algorithm: An Inherently Parallel Generalization of
Heapsort | 4 pages, 4 figures | null | null | null | cs.DS cs.CC cs.DC | null | A generalization of the heapsort algorithm is proposed. At the expense of
about 50% more comparison and move operations for typical cases, the dualheap
sort algorithm offers several advantages over heapsort: improved cache
performance, better performance if the input happens to be already sorted, and
easier parallel implementations.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 14:42:45 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Sepesi",
"Greg",
""
]
] |
0706.2894 | Santabrata Das | Santabrata Das and Sandip K. Chakrabarti | Properties of accretion shock waves in viscous flows with cooling
effects | 3 pages; 3 figures; prepared on the basis of the talk presented in
the MG11 Meeting on General Relativity, Berlin, July 23-29, 2006 | null | 10.1142/9789812834300_0072 | null | astro-ph | null | We study the properties of the shock waves for a viscous accretion flow
having low angular momentum in presence of synchrotron cooling. We present all
possible accretion solutions in terms of flow parameters. We identify the
region of the parameter space for steady and oscillating shocks and show the
effect of various energy dissipation processes on it. We discuss the role of
the shock waves while explaining the observations from black hole candidates.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 00:58:22 GMT"
}
] | 2016-11-15T00:00:00 | [
[
"Das",
"Santabrata",
""
],
[
"Chakrabarti",
"Sandip K.",
""
]
] |
0706.2895 | Panagiotis Stinis | Panagiotis Stinis | Dimensional reduction as a tool for mesh refinement and tracking
singularities of PDEs | 46 pages, 24 figures | null | null | LBNL-62851 | math.NA math.AP | null | We present a collection of algorithms which utilize dimensional reduction to
perform mesh refinement and study possibly singular solutions of time-dependent
partial differential equations. The algorithms are inspired by constructions
used in statistical mechanics to evaluate the properties of a system near a
critical point. The first algorithm allows the accurate determination of the
time of occurrence of a possible singularity. The second algorithm is an
adaptive mesh refinement scheme which can be used to approach efficiently the
possible singularity. Finally, the third algorithm uses the second algorithm
until the available resolution is exhausted (as we approach the possible
singularity) and then switches to a dimensionally reduced model which, when
accurate, can follow faithfully the solution beyond the time of occurrence of
the purported singularity. An accurate dimensionally reduced model should
dissipate energy at the right rate. We construct two variants of each
algorithm. The first variant assumes that we have actual knowledge of the
reduced model. The second variant assumes that we know the form of the reduced
model, i.e. the terms appearing in the reduced model, but not necessarily their
coefficients. In this case, we also provide a way of determining the
coefficients. We present numerical results for the Burgers equation with zero
and nonzero viscosity to illustrate the use of the algorithms.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 01:22:15 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Stinis",
"Panagiotis",
""
]
] |
0706.2896 | Santabrata Das | Santabrata Das and Sandip K. Chakrabarti | Parameter space study of magnetohydrodynamic flows around magnetized
compact objects | 3 pages; 4 figures; prepared on the basis of the talk presented in
the MG11 Meeting on General Relativity, Berlin, July 23-29, 2006 | null | 10.1111/j.1365-2966.2006.11185.x | null | astro-ph | null | We solve the magnetohydrodynamic (MHD) equations governing axisymmetric flows
around neutron stars and black holes and found all possible solution topologies
for adiabatic accretion. We divide the parameter space spanned by the conserved
energy and angular momentum of the flow in terms of the flow topologies. We
also study the possibility of the formation of the MHD shock waves.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 01:17:24 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Das",
"Santabrata",
""
],
[
"Chakrabarti",
"Sandip K.",
""
]
] |
0706.2897 | Georg Hoffstaetter | Georg H. Hoffstaetter, Christian Spethmann | Equilibrium ion distribution in the presence of clearing electrodes and
its influence on electron dynamics | null | Phys.Rev.STAccel.Beams11:014001,2008 | 10.1103/PhysRevSTAB.11.014001 | null | physics.acc-ph physics.comp-ph | null | Here we compute the ion distribution produced by an electron beam when
ion-clearing electrodes are installed. This ion density is established as an
equilibrium between gas ionization and ion clearing. The transverse ion
distributions are shown to strongly peak in the beam's center, producing very
nonlinear forces on the electron beam. We will analyze perturbations to the
beam properties by these nonlinear fields. To obtain reasonable simulation
speeds, we develop fast algorithms that take advantage of adiabatic invariants
and scaling properties of Maxwell's equations and the Lorentz force.
Our results are very relevant for high current Energy Recovery Linacs, where
ions are produced relatively quickly, and where clearing gaps in the electron
beam cannot easily be used for ion elimination. The examples in this paper
therefore use parameters of the Cornell Energy Recovery Linac project. For
simplicity we only consider the case of a circular electron beam of changing
diameter. However, we parameterize this model to approximate non-round beams
well. We find suitable places for clearing electrodes and compute the
equilibrium ion density and its effect on electron-emittance growth and halo
development. We find that it is not sufficient to place clearing electrodes
only at the minimum of the electron beam potential where ions are accumulated.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:14:25 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Hoffstaetter",
"Georg H.",
""
],
[
"Spethmann",
"Christian",
""
]
] |
0706.2898 | Nora Ganter | Nora Ganter | Hecke operators in equivariant elliptic cohomology and generalized
moonshine | 38 pages, 1 figure. Groups and symmetries: from the Neolithic Scots
to John McKay, 173-209, CRM Proc. Lecture Notes, 47, Amer. Math. Soc.,
Providence, RI, 2009 | null | null | null | math.AT math.GR | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This paper studies connections between generalized moonshine and elliptic
cohomology with a focus on the action of the Hecke correspondence and its
implications for the notion of replicability.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:09:00 GMT"
},
{
"version": "v2",
"created": "Mon, 7 Dec 2015 09:28:42 GMT"
}
] | 2015-12-08T00:00:00 | [
[
"Ganter",
"Nora",
""
]
] |
0706.2899 | Guanrong Chen | Zhisheng Duan, Guanrong Chen and Lin Huang | Disconnected synchronized regions of complex dynamical networks | 13 pages, 2 figures | null | null | null | math.CO | null | This paper addresses the synchronized region problem, which is reduced to a
matrix stability problem, for complex dynamical networks. For any natural
number $n$, the existence of a network which has $n$ disconnected synchronized
regions is theoretically demonstrated. This shows the complexity in network
synchronization. Convexity characteristic of stability for matrix pencils is
further discussed. Smooth and generalized smooth Chua's circuit networks are
finally discussed as examples for illustration.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:15:20 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Duan",
"Zhisheng",
""
],
[
"Chen",
"Guanrong",
""
],
[
"Huang",
"Lin",
""
]
] |
0706.2900 | David Boboltz | David A. Boboltz, Kevin B. Marvel | Water Maser Kinematics in the Jet of OH 12.8-0.9 | 25 pages, 6 figures, accepted for publication in the ApJ | Astrophys.J.665:680-689,2007 | 10.1086/519067 | null | astro-ph | null | We present Very Long Baseline Array observations of the kinematics of the
water masers associated with OH 12.8-0.9, the fourth member of the so-called
"water fountain" class of sources. We find that the masers occupy two distinct
regions at the ends of a bipolar jet-like structure oriented north-south, with
the blue-shifted masers located to the north and the red-shifted masers to the
south. The masers are distributed along arc-like structures 12-20 mas across
oriented perpendicular to the separation axis with an angular separation of
~110 mas on the sky. Our multi-epoch observations, show the two maser arcs to
be expanding away from each other along the axis of separation. The relative
proper motions of the two maser regions is 2.7 mas/yr (~105 km/s at the assumed
distance of 8 kpc). The measured radial velocity difference between the
northern, blue-shifted masers and the southern, red-shifted masers is 48.4
km/s. The radial velocity, when combined with the proper motion, yields a
three-dimensional expansion velocity of 58 km/s and an inclination angle of 24
deg. for the jet. By combining our radial velocities with historical values, we
estimate the three dimensional acceleration of the masers to be ~0.63 km/s/yr
and a dynamical age for the collimated outflow of ~90 yr.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:18:43 GMT"
}
] | 2011-02-11T00:00:00 | [
[
"Boboltz",
"David A.",
""
],
[
"Marvel",
"Kevin B.",
""
]
] |
0706.2901 | Guanrong Chen | Zhisheng Duan, Guanrong Chen and Lin Huang | Analysis and control of network synchronizability | 12 pages, 8 figures | null | null | null | math.CO | null | In this paper, the investigation is first motivated by showing two examples
of simple regular symmetrical graphs, which have the same structural
parameters, such as average distance, degree distribution and node betweenness
centrality, but have very different synchronizabilities. This demonstrates the
complexity of the network synchronizability problem. For a given network with
identical node dynamics, it is further shown that two key factors influencing
the network synchronizability are the network inner linking matrix and the
eigenvalues of the network topological matrix. Several examples are then
provided to show that adding new edges to a network can either increase or
decrease the network synchronizability. In searching for conditions under which
the network synchronizability may be increased by adding edges, it is found
that for networks with disconnected complementary graphs, adding edges never
decreases their synchronizability. This implies that better understanding and
careful manipulation of the complementary graphs are important and useful for
enhancing the network synchronizability. Moreover, it is found that an
unbounded synchronized region is always easier to analyze than a bounded
synchronized region. Therefore, to effectively enhance the network
synchronizability, a design method is finally presented for the inner linking
matrix of rank 1 such that the resultant network has an unbounded synchronized
region, for the case where the synchronous state is an equilibrium point of the
network.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:19:43 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Duan",
"Zhisheng",
""
],
[
"Chen",
"Guanrong",
""
],
[
"Huang",
"Lin",
""
]
] |
0706.2902 | Guanrong Chen | Zhisheng Duan, Jinzhi Wang, Guanrong Chen and Lin Huang | Complexity in linearly coupled dynamical networks: Some unusual
phenomena in energy accumulation | 12 pages, 2 figures | null | null | null | math.OC math.DS | null | This paper addresses the energy accumulation problem, in terms of the $H_2$
norm, of linearly coupled dynamical networks. An interesting outer-coupling
relationship is constructed, under which the $H_2$ norm of the newly
constructed network with column-input and row-output shaped matrices increases
exponentially fast with the node number $N$: it increases generally much faster
than $2^N$ when $N$ is large while the $H_2$ norm of each node is 1. However,
the $H_2$ norm of the network with a diffusive coupling is equal to $\gamma_2
N$, i.e., increasing linearly, when the network is stable, where $\gamma_2$ is
the $H_2$ norm of a single node. And the $H_2$ norm of the network with
antisymmetrical coupling also increases, but rather slowly, with the node
number $N$. Other networks with block-diagonal-input and block-diagonal-output
matrices behave similarly. It demonstrates that the changes of $H_2$ norms in
different networks are very complicated, despite the fact that the networks are
linear. Finally, the influence of the $H_2$ norm of the locally linearized
network on the output of a network with Lur'e nodes is discussed.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:23:22 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Duan",
"Zhisheng",
""
],
[
"Wang",
"Jinzhi",
""
],
[
"Chen",
"Guanrong",
""
],
[
"Huang",
"Lin",
""
]
] |
0706.2903 | Jason Tumlinson | Jason Tumlinson | Carbon-Enhanced Metal-Poor Stars, the Cosmic Microwave Background, and
the Stellar IMF in the Early Universe | 7 pages emulateapj format, three figures, accepted for ApJ Letters | null | 10.1086/520930 | null | astro-ph | null | The characteristic mass of stars at early times may have been higher than
today owing to the cosmic microwave background (CMB). This study proposes that
(1) the testable predictions of this "CMB-IMF" hypothesis are an increase in
the fraction of carbon-enhanced metal-poor (CEMP) stars with declining
metallicity and an increase from younger to older populations at a single
metallicity (e.g. disk to halo), and (2) these signatures are already seen in
recent samples of CEMP stars and can be better tested with anticipated data.
The expected spatial variation may explain discrepancies of CEMP frequency
among published surveys. The ubiquity and time dependence of the CMB will
substantially alter the reconstruction of star formation histories in the Local
Group and early Universe.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 14:54:37 GMT"
}
] | 2009-11-13T00:00:00 | [
[
"Tumlinson",
"Jason",
""
]
] |
0706.2904 | Sang Chul Kim | Sang Chul Kim (KASI), Myung Gyoon Lee (SNU), Doug Geisler (UdeC), Ata
Sarajedini (UF), Hong Soo Park (SNU), Ho Seong Hwang (SNU), William E. Harris
(McMasterU), Juan C. Seguel (UdeC), Ted von Hippel (UTAustin) | Wide-Field Survey of Globular Clusters in M31. I. A Catalog of New
Clusters | accepted by AJ, using emulateapj.cls | Astron.J.134:706-720,2007 | 10.1086/519556 | null | astro-ph | null | We present the result of a wide-field survey of globular clusters (GCs) in
M31 covering a 3deg x 3deg field c. We have searched for GCs on CCD images
taken with Washington CMT1 filters at the KPNO 0.9 m telescope using steps: (1)
inspection of morphological parameters given by the SExtractor package such as
stellarity, full maximum, and ellipticity; (2) consulting the spectral types
and radial velocities obtained from spectra takena spectrograph at the WIYN 3.5
m telescope; and (3) visual inspection of the images of each object. We have
and GC candidates, of which 605 are newly found GCs and GC candidates and 559
are previously known GCs. Amoects there are 113 genuine GCs, 258 probable GCs,
and 234 possible GCs, according to our classification critee known objects
there are 383 genuine GCs, 109 probable GCs, and 67 possible GCs. In total
there are 496 genprobable GCs and 301 possible GCs. Most of these newly found
GCs have T1 magnitudes of 17.5 - 19.5 mag, [17.9 < V < 19.9 mag assuming (C-T1)
~ 1.5], and (C-T1) colors in the range 1 - 2.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 02:42:18 GMT"
},
{
"version": "v2",
"created": "Thu, 21 Jun 2007 04:37:17 GMT"
}
] | 2010-11-05T00:00:00 | [
[
"Kim",
"Sang Chul",
"",
"KASI"
],
[
"Lee",
"Myung Gyoon",
"",
"SNU"
],
[
"Geisler",
"Doug",
"",
"UdeC"
],
[
"Sarajedini",
"Ata",
"",
"UF"
],
[
"Park",
"Hong Soo",
"",
"SNU"
],
[
"Hwang",
"Ho Seong",
"",
"SNU"
],
[
"Harris",
"William E.",
"",
"McMasterU"
],
[
"Seguel",
"Juan C.",
"",
"UdeC"
],
[
"von Hippel",
"Ted",
"",
"UTAustin"
]
] |
0706.2905 | Myungseok Yoon | Chang-Young Ee, Daeho Lee, and Myungseok Yoon | Entropy of Schwarzschild Black Holes on DGP Brane | 6 pages, 1 figure; to appear in J. Kor. Phys. Soc | J.Korean Phys.Soc. 51 (2007) 2091-2093 | null | null | gr-qc | null | We study the entropy of Schwarzschild black holes on DGP brane. The radius of
event horizon on DGP brane is obtained by a numerical method. It is smaller
than that of Einstein gravity in the conventional branch, and is larger in the
accelerated branch. However, the difference is very small. The entropy of the
black hole is calculated by using the improved brick-wall method.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 03:29:54 GMT"
},
{
"version": "v2",
"created": "Fri, 2 Nov 2007 05:32:31 GMT"
}
] | 2008-10-21T00:00:00 | [
[
"Ee",
"Chang-Young",
""
],
[
"Lee",
"Daeho",
""
],
[
"Yoon",
"Myungseok",
""
]
] |
0706.2906 | Rahul Vaze | Rahul Vaze and Robert W. Heath Jr | Capacity Scaling for MIMO Two-Way Relaying | null | null | null | null | cs.IT math.IT | null | A multiple input multiple output (MIMO) two-way relay channel is considered,
where two sources want to exchange messages with each other using multiple
relay nodes, and both the sources and relay nodes are equipped with multiple
antennas. Both the sources are assumed to have equal number of antennas and
have perfect channel state information (CSI) for all the channels of the MIMO
two-way relay channel, whereas, each relay node is either assumed to have CSI
for its transmit and receive channel (the coherent case) or no CSI for any of
the channels (the non-coherent case). The main results in this paper are on the
scaling behavior of the capacity region of the MIMO two-way relay channel with
increasing number of relay nodes. In the coherent case, the capacity region of
the MIMO two-way relay channel is shown to scale linearly with the number of
antennas at source nodes and logarithmically with the number of relay nodes. In
the non-coherent case, the capacity region is shown to scale linearly with the
number of antennas at the source nodes and logarithmically with the signal to
noise ratio.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 03:33:02 GMT"
},
{
"version": "v2",
"created": "Thu, 19 Jul 2007 05:12:34 GMT"
},
{
"version": "v3",
"created": "Mon, 7 Apr 2008 15:59:18 GMT"
}
] | 2008-04-07T00:00:00 | [
[
"Vaze",
"Rahul",
""
],
[
"Heath",
"Robert W.",
"Jr"
]
] |
0706.2907 | Jon Yard | Jon Yard, Igor Devetak | Optimal quantum source coding with quantum information at the encoder
and decoder | Final version | IEEE Transactions on Information Theory ( Volume: 55 , Issue: 11 ,
Nov. 2009 ) | 10.1109/TIT.2009.2030494 | null | quant-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Consider many instances of an arbitrary quadripartite pure state of four
quantum systems ABCD. Alice holds the AC part of each state, Bob holds B, while
D represents all other parties correlated with ABC. Alice is required to
redistribute the C systems to Bob while asymptotically preserving the overall
purity. We prove that this is possible using Q qubits of communication and E
ebits of shared entanglement between Alice and Bob, provided that Q geq
I(C;D|B)/2 and Q+E geq H(C|B), proving the optimality of the Luo-Devetak outer
bound. The optimal qubit rate provides the first known operational
interpretation of quantum conditional mutual information. We also show how our
protocol leads to a fully operational proof of strong subadditivity and uncover
a general organizing principle, in analogy to thermodynamics, that underlies
the optimal rates.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:19:54 GMT"
},
{
"version": "v2",
"created": "Sat, 26 Sep 2020 20:02:56 GMT"
}
] | 2020-09-29T00:00:00 | [
[
"Yard",
"Jon",
""
],
[
"Devetak",
"Igor",
""
]
] |
0706.2908 | Stephanie van Willigenburg | M.D. Atkinson, G. Pfeiffer, S.J. van Willigenburg | The $p$-modular descent algebras | 21 pages; Original version of Algebr. Represent. Theory 5:101-113
(2002). Journal version can be found at
http://www.math.ubc.ca/~steph/pub.html | Algebr. Represent. Theory 5:101-113 (2002) | null | null | math.CO | null | The concept of descent algebras over a field of characteristic zero is
extended to define descent algebras over a field of prime characteristic. Some
basic algebraic structure of the latter, including its radical and irreducible
modules, is then determined. The decomposition matrix of the descent algebras
of Coxeter group types $A$, $B$, and $D$ are calculated, and used to derive a
description of the decomposition matrix of an arbitrary descent algebra. The
Cartan matrix of a variety of descent algebras over a finite field is then
obtained.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:19:19 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Atkinson",
"M. D.",
""
],
[
"Pfeiffer",
"G.",
""
],
[
"van Willigenburg",
"S. J.",
""
]
] |
0706.2909 | Abraham Harte | Abraham I. Harte | Extended-body effects in cosmological spacetimes | 14 pages, minor clarifications added | Class.Quant.Grav.24:5161-5172,2007 | 10.1088/0264-9381/24/20/015 | null | gr-qc | null | We study the dynamics of extended test bodies in flat
Friedmann-Robertson-Walker spacetimes. It is shown that such objects can
usually alter their inertial mass, spin, and center-of-mass trajectory purely
through the use of internal deformations. Many of these effects do not have
Newtonian analogs, and exist despite the presence of conserved momenta
associated with the translational and rotational symmetries of the background.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:29:24 GMT"
},
{
"version": "v2",
"created": "Tue, 2 Oct 2007 16:56:37 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Harte",
"Abraham I.",
""
]
] |
0706.2910 | Stephanie van Willigenburg | Stephanie van Willigenburg | Properties of the descent algebras of type $D$ | 7 pages | Discrete Math. 269: 325--332 (2003) | null | null | math.CO | null | We establish simple combinatorial descriptions of the radical and irreducible
representations specifically for the descent algebra of a Coxeter group of type
$D$ over any field.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:30:05 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"van Willigenburg",
"Stephanie",
""
]
] |
0706.2911 | Takayuki Myo | Takayuki Myo, Kiyoshi Kato, Hiroshi Toki, Kiyomi Ikeda | Roles of the tensor and pairing correlations on the halo formation in
11Li | 8 pages, 5 figures | Phys.Rev.C76:024305,2007 | 10.1103/PhysRevC.76.024305 | null | nucl-th | null | We study the roles of the tensor and pairing correlations on the halo
formation in 11Li with an extended 9Li+n+n model. We first solve the ground
state of 9Li in the shell model basis by taking 2p-2h states using the Gaussian
functions with variational size parameters to take into account the tensor
correlation fully. In 11Li, the tensor and pairing correlations in 9Li are
Pauli-blocked by additional two neutrons, which work coherently to make the
configurations containing the 0p1/2 state pushed up and close to those
containing the 1s1/2 state. Hence, the pairing interaction works efficiently to
mix the two configurations by equal amount and develop the halo structure in
11Li. For 10Li, the inversion phenomenon of s- and p-states is reproduced in
the same framework. Our model furthermore explains the recently observed
Coulomb breakup strength and charge radius for 11Li.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:46:39 GMT"
}
] | 2008-11-26T00:00:00 | [
[
"Myo",
"Takayuki",
""
],
[
"Kato",
"Kiyoshi",
""
],
[
"Toki",
"Hiroshi",
""
],
[
"Ikeda",
"Kiyomi",
""
]
] |
0706.2912 | Satoshi Aoki | Satoshi Aoki and Masami Miyakawa | Statistical testing procedure for the interaction effects of several
controllable factors in two-valued input-output systems | 14pages | null | null | null | stat.ME | null | Suppose several two-valued input-output systems are designed by setting the
levels of several controllable factors. For this situation, Taguchi method has
proposed to assign the controllable factors to the orthogonal array and use
ANOVA model for the standardized SN ratio, which is a natural measure for
evaluating the performance of each input-output system. Though this procedure
is simple and useful in application indeed, the result can be unreliable when
the estimated standard errors of the standardized SN ratios are unbalanced. In
this paper, we treat the data arising from the full factorial or fractional
factorial designs of several controllable factors as the frequencies of
high-dimensional contingency tables, and propose a general testing procedure
for the main effects or the interaction effects of the controllable factors.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:48:48 GMT"
}
] | 2007-06-21T00:00:00 | [
[
"Aoki",
"Satoshi",
""
],
[
"Miyakawa",
"Masami",
""
]
] |
0706.2913 | Juhn-Jong Lin | S. M. Huang, T. C. Lee, H. Akimoto, K. Kono, and J. J. Lin | Observation of strong electron dephasing in disordered
Cu$_{93}$Ge$_4$Au$_3$ thin films | to appear in Phys. Rev. Lett | Phys. Rev. Lett. 99, 046601 (2007) | 10.1103/PhysRevLett.99.046601 | null | cond-mat.mes-hall | null | We report the observation of strong electron dephasing in a series of
disordered Cu$_{93}$Ge$_4$Au$_3$ thin films. A very short electron dephasing
time possessing very weak temperature dependence around 6 K, followed by an
upturn with further decrease in temperature below 4 K, is found. The upturn is
progressively more pronounced in more disordered samples. Moreover, a ln$T$
dependent, but high-magnetic-field-insensitive, resistance rise persisting from
above 10 K down to 30 mK is observed in the films. These results suggest a
nonmagnetic dephasing process which is stronger than any known mechanism and
may originate from the coupling of conduction electrons to dynamic defects.
| [
{
"version": "v1",
"created": "Wed, 20 Jun 2007 04:52:00 GMT"
}
] | 2011-11-10T00:00:00 | [
[
"Huang",
"S. M.",
""
],
[
"Lee",
"T. C.",
""
],
[
"Akimoto",
"H.",
""
],
[
"Kono",
"K.",
""
],
[
"Lin",
"J. J.",
""
]
] |
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