March 2008 arXiv papers — page 35

Janet Anders

We investigate the entanglement properties of thermal states of the harmonic lattice in one, two and three dimensions. We establish the value of the critical temperature for entanglement between neighbouring sites and give physical reasons. Further sites are shown to be entangled only due to boundary effects. Other forms of entanglement are addressed in the

Takahiro Onimaru, Yukihiro F. Inoue, Keisuke Shigetoh, Kazunori Umeo

Electrical resistivity rho, magnetic susceptibility chi, magnetization M and specific heat measurements are reported on a singlecrystalline sample of CePd5Al2, showing successive antiferromagnetic orderings at T_N1=4.1 K and T_N2=2.9 K. The temperature dependence of T_N1 shows a Kondo metal behavior with large anisotropy, rho_c/rho_a=3.2 at 20 K, and opening

Luis A. Pugnaloni, Martin Mizrahi, Carlos M. Carlevaro, Fernando Vericat

We present results from four independent models of a granular assembly subjected to tapping. We find that the steady-state packing fraction as a function of the tapping intensity is nonmonotonic. In particular, for high tapping intensities, we observe an increase of the packing fraction with tapping strength. This finding challenges the current understanding

Valentin Savin

Iterative decoding of non-binary LDPC codes is currently performed using either the Sum-Product or the Min-Sum algorithms or slightly different versions of them. In this paper, several low-complexity quasi-optimal iterative algorithms are proposed for decoding non-binary codes. The Min-Max algorithm is one of them and it has the benefit of two possible LLR d

Sarah Mostame, Ralf Schützhold

We propose a physical setup that can be used to simulate the quantum dynamics of the Ising model with present-day technology. Our scheme consists of electrons floating on superfluid helium which interact via Coulomb forces. In the limit of low temperatures, the system will stay near the ground state where its Hamiltonian is equivalent to the Ising model and

Levon Tamaryan, DaeKil Park, Jin-Woo Son, Sayatnova Tamaryan

We give an explicit expression for the geometric measure of entanglement for three qubit states that are linear combinations of four orthogonal product states. It turns out that the geometric measure for these states has three different expressions depending on the range of definition in parameter space. Each expression of the measure has its own geometrical

Valentin Savin

In this paper we propose a very simple but powerful self-correction method for the Min-Sum decoding of LPDC codes. Unlike other correction methods known in the literature, our method does not try to correct the check node processing approximation, but it modifies the variable node processing by erasing unreliable messages. However, this positively affects ch

Shigeki Matsutani

In the previous article (Found Phys. Lett. {\bf{16}} 325-341), we showed that a reciprocity of the Gauss sums is connected with the wave and particle complementary. In this article, we revise the previous investigation by considering a relation between the Gauss optics and the Gauss sum based upon the recent studies of the Weil representation for a finite gr

Yoshimi Yoshino, Tobias Galla, Kei Tokita

We present a non-equilibrium statistical mechanics description of rank abundance relations (RAR) in random community models of ecology. Specifically, we study a multi-species replicator system with quenched random interaction matrices. We here consider symmetric interactions as well as asymmetric and anti-symmetric cases. RARs are obtained analytically via a

M. Kleinmann, H. Kampermann, D. Bruss

We analyze the optimal unambiguous discrimination of two arbitrary mixed quantum states. We show that the optimal measurement is unique and we present this optimal measurement for the case where the rank of the density operator of one of the states is at most 2 ("solution in 4 dimensions"). The solution is illustrated by some examples. The optimality

S. A. Appleby, R. A. Battye

We study cosmological expansion in F(R) gravity using the trace of the field equations. High frequency oscillations in the Ricci scalar, whose amplitude increase as one evolves backward in time, have been predicted in recent works. We show that the approximations used to derive this result very quickly breakdown in any realistic model due to the non-linear n

Ashoke Sen

We construct the partition function of 1/8 BPS dyons in type II string theory on T^6 from counting of microstates of a D1-D5 system in Taub-NUT space. Our analysis extends the earlier ones by Shih, Strominger and Yin and by Pioline by taking into account the walls of marginal stability on which a 1/8 BPS dyon can decay into a pair of half-BPS dyons. Across t

Stéphane Nonnenmacher, Emmanuel Schenck

In order to study the resonance spectra of chaotic cavities subject to some damping (which can be due to absorption or partial reflection at the boundaries), we use a model of damped quantum maps. In the high-frequency limit, the distribution of (quantum) decay rates is shown to cluster near a ``typical'' value, which is larger than the classical dec

Run-Hui Li, Cai-Dian Lü, Hao Zou

Two-body non-leptonic charmed decays $B_{(s)} \to D_{(s)}P$, $D_{(s)}^*P$, $D_{(s)}V$ and $D_{(s)}^*V$ are analyzed in perturbative QCD approach, where $P$ and $V$ denote the light pseudoscalar meson and vector meson, respectively. We test the $D$ meson wave function by a $χ^2$ fit with experimental data of six $B\to DP$ channels. We give the branching ratio

J. Tailleur, M. E. Cates

We consider self-propelled particles undergoing run-and-tumble dynamics (as exhibited by E. coli) in one dimension. Building on previous analyses at drift-diffusion level for the one-particle density, we add both interactions and noise, enabling discussion of domain formation by "self-trapping", and other collective phenomena. Mapping onto detailed-b

T. Yamano, O. Iguchi

The Csiszár f-divergence, which is a class of information distances, is known to offer a useful tool for analysing the classical counterpart of the cloning operations that are quantum mechanically impossible for the factorized and marginality classical probability distributions under Liouville dynamics. We show that a class of information distances that does

B. Iochum, C. Levy, A. Sitarz

The spectral action on the equivariant real spectral triple over \A(SU_q(2)) is computed explicitly. Properties of the differential calculus arising from the Dirac operator are studied and the results are compared to the commutative case of the sphere S^3.

S. Costamagna, J. A. Riera

We study the two-impurity Anderson model on finite chains using numerical techniques. We discuss the departure of magnetic correlations as a function of the interimpurity distance from a pure 2k_F oscillation due to open boundary conditions. We observe qualitatively different behaviors in the interimpurity spin correlations and in transport properties at dif

Rémi Langevin, Jun O'Hara

The set of osculating circles of a given curve in $\SS^3$ forms a curve in the set of oriented circles in $\SS^3$. We show that its "${\frac12}$-dimensional measure" with respect to the pseudo-Riemannian structure of the set of circles is proportional to the conformal arc-length of the original curve, which is a conformally invariant local quantity d

Koenraad Audenaert, Liang Cai, Frank Hansen

We study quantum information inequalities and show that the basic inequality between the quantum variance and the metric adjusted skew information generates all the multi-operator matrix inequalities or Robertson type determinant inequalities studied by a number of authors. We introduce an order relation on the set of functions representing quantum Fisher in

David K. Sing, A. Vidal-Madjar, A. Lecavelier des Etangs, J. -M. Desert

We present a theoretical model fit to the HST/STIS optical transit transmission spectrum of HD209458b. In our fit, we use the sodium absorption line profile along with the Rayleigh scattering by H_2 to help determine the average temperature-pressure profile at the planetary terminator, and infer the abundances of atomic and molecular species. The observed so

Franz Wegner

Three-dimensional central symmetric bodies different from spheres that can float in all orientations are considered. For relative density rho=1/2 there are solutions, if holes in the body are allowed. For rho different from 1/2 the body is deformed from a sphere. A set of nonlinear shape-equations determines the shape in lowest order in the deformation. It i

M. Rozyczka, J. Kaluzny, W. Krzeminski, B. Mazur

We present the results of a variable stars search in the field of the old open cluster NGC 2204. Five new variables were found, four of them being eclipsing binaries. The sample includes a detached binary located at the turnoff, a W UMa - type system, and an interesting detached low-mass binary with a period of 0.45d which, however, is a foreground object. W

Hirotaka Tamanoi

To open-closed cobordism surfaces, open-closed string topology associates topological quantum field theory (TQFT) operations, namely string operations, which depend only on homeomorphism types of surfaces and which satisfy the sewing property. We show that most TQFT string operations vanish in open-closed string topology. We describe those open-closed cobord

Taro Nagao, G. J. Rodgers

In order to clarify the statistical features of complex networks, the spectral density of adjacency matrices has often been investigated. Adopting a static model introduced by Goh, Kahng and Kim, we analyse the spectral density of complex scale free networks. For that purpose, we utilize the replica method and effective medium approximation (EMA) in statisti

Hirotaka Tamanoi

Previously, we showed that most of the open-closed topological quantum field theory (TQFT) string operations vanish including all the higher genus TQFT operations, and we described a small list of genus zero open-closed TQFT string operations which can be nontrivial. In this paper, we consider open-closed string operations associated to open-closed cobordism

Harald Grosse, Fabien Vignes-Tourneret

We prove that the self-interacting scalar field on the four-dimensional degenerate Moyal plane is renormalisable to all orders when adding a suitable counterterm to the Lagrangean. Despite the apparent simplicity of the model, it raises several non trivial questions. Our result is a first step towards the definition of renormalisable quantum field theories o

Assane Lo

The aim of this paper is to solve the three dimensional Navier-Stokes problem with conservative source term. We use convolution methods to construct "well behaved" smooth solutions of the initial boundary value problem for the system of Navier-Stokes with conservative source term.

Makoto Tagami

Beck et. al. characterized the grid graphs whose perfect matching polytopes are Gorenstein and they also showed that for some parameters, perfect matching polytopes of torus graphs are Gorenstein. In this paper, we complement their result, that is, we characterize the torus graphs whose perfect matching polytopes are Gorenstein. Beck et. al. also gave a meth

A. S. Danagulyan, A. R. Balabekyan, G. H. Hovhannisyan, N. A. Demekhina

Isospin effects in 12C ion induced reactions on enriched tin isotopes are investigated. The isoscaling parameter B is determined for different mass regions of product nuclei. It is shown that the isoscaling parameter is sensitive to the formation mechanism of products, and increases as the difference in the asymmetry is increasing. Using the exitatation ener

S. Mendoza, E. Tejeda, E. Nagel

We construct a steady analytic accretion flow model for a finite rotating gas cloud that accretes material to a central gravitational object. The pressure gradients of the flow are considered to be negligible and so, the flow is ballistic. We also assume a steady flow and consider the particles at the boundary of the spherical cloud to be rotating as a rigid

Suho Oh

Postnikov gave a combinatorial description of the cells in a totally-nonnegative Grassmannian. These cells correspond to a special class of matroids called positroid. We prove his conjecture that a positroid is exactly an intersection of permuted Schubert matroids. This leads to a nice combinatorial description of positroids that is easily computable.

Xiao-Gang Wen, Zhenghan Wang

It has been shown that different Abelian and non-Abelian fraction quantum Hall states can be characterized by patterns of zeros described by sequences of integers {S_a}. In this paper, we will show how to use the data {S_a} to calculate various topological properties of the corresponding fraction quantum Hall state, such as the number of possible quasipartic

Artem Pulemotov

The paper pursues two connected goals. Firstly, we establish the Li-Yau-Hamilton estimate for the heat equation on a manifold $M$ with nonempty boundary. Results of this kind are typically used to prove monotonicity formulas related to geometric flows. Secondly, we establish bounds for a solution $\nabla(t)$ of the Yang-Mills heat equation in a vector bundle

Zong-Kuan Guo, Nobuyoshi Ohta

We investigate the cosmological evolution of the system of a Dirac-Born-Infeld field plus a perfect fluid. We analyze the existence and stability of scaling solutions for the AdS throat and the quadratic potential. We find that the scaling solutions exist when the equation of state of the perfect fluid is negative and in the ultra-relativistic limit.

Chun-Hua Yuan, Cui-Ping Lu, Weiping Zhang, L. Deng

A scheme of generating controllable (2+1) photons in a double-$% Λ$ atomic system based on active-Raman-gain is presented in this paper. Such (2+1) photons can be a potential candidate to generate a correlated photon pair as the photon `1' acts as a trigger. Compared to other schemes of generating correlated photon pairs, our scheme exhibits a number of

S. Laporta

In this paper we continue the work begun in 2002 on the identification of the analytical expressions of Feynman integrals which require the evaluation of multiple elliptic integrals. We rewrite and simplify the analytical expression of the 3-loop self-mass integral with three equal masses and on-shell external momentum. We collect and analyze a number of res

C. P. Morath, J. A. Seamons, J. L. Reno, M. P. Lilly

The layer interdependence of transport in an undoped electron-hole bilayer (uEHBL) device was studied as a function of carrier density, interlayer electric field, and temperature. The uEHBL device consisted of a density tunable, independently contacted two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) induced via field effect in distinc

Frederik Denef

These lectures give a detailed introduction to constructing and analyzing string vacua suitable for phenomenological model building, with particular emphasis on F-theory flux vacua. Topics include (1) general challenges and overview of some proposed scenarios, (2) an extensive introduction to F-theory and its relation to M-theory and perturbative IIB string

Jacopo De Simoi

We consider the static wall approximation to the dynamics of a particle bouncing on a periodically oscillating infinitely heavy plate while subject to a potential force. We assume the case of a potential given by a power of the particle's height and sinusoidal motions of the plate. We find that for powers smaller than 1 the set of escaping orbits has ful

Yang Liu, Karin A. Dahmen, A. Berger

The $ΔH(M, ΔM)$ method and its ability to determine intrinsic switching field distributions of perpendicular recording media are numerically studied. It is found that the presence of dipolar interactions in the range of typical recording media substantially enhances the reliability of the $ΔH(M,ΔM)$ method. In addition, a strong correlation is observed betwe

H. Tashiro, J. M. Graybeal, D. B. Tanner, E. J. Nicol

Thin films of $α$-MoGe show progressively reduced $T_{c}$'s as the thickness is decreased below 30 nm and the sheet resistance exceeds 100 $Ω/\Box$. We have performed far-infrared transmission and reflection measurements for a set of $α$-MoGe films to characterize this weakened superconducting state. Our results show the presence of an energy gap with ra

Eric G. Daub, M. Lisa Manning, Jean M. Carlson

We study strain localization as an enhanced velocity weakening mechanism on earthquake faults. Fault friction is modeled using Shear Transformation Zone (STZ) Theory, a microscopic physical model for non-affine rearrangements in granular fault gouge. STZ Theory is implemented in spring slider and dynamic rupture models of faults. We compare dynamic shear loc

Edouard J. Bernard, Carme Gallart, Matteo Monelli, Antonio Aparicio

We present a study of the radial distribution of RR Lyrae variables, which present a range of photometric and pulsational properties, in the dwarf spheroidal galaxy Tucana. We find that the fainter RR Lyrae stars, having a shorter period, are more centrally concentrated than the more luminous, longer period RR Lyrae variables. Through comparison with the pre

J. B. Hutchings, L. Bianchi

We discuss selection of QSO candidates from the combined SDSS and GALEX catalogues. We discuss properties of QSOs within the combined sample, and note uncertainties in number counts and completeness, compared with other SDSS-based samples. We discuss colour and other properties with redshift within the sample and the SEDs for subsets. We estimate the numbers

Jay Stine, M. V. Mielke

This paper introduces three separation conditions for topological spaces, called T_{0,1}, T_{0,2} ("pre-Hausdorff"), and T_{1,2}. These conditions generalize the classical T_(1) and T_(2) separation axioms, and they have advantages over them topologically which we discuss. We establish several different characterizations of pre-Hausdorff spaces, and

J. F. Helmboldt, G. B. Taylor, R. C. Walker, R. D. Blanford

A detailed analysis of the evolution of the properties of core-jet systems within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a power-law relationship between jet intensity and width that suggests for the typical jet, little if any energy is lost as it moves away from its core. Using VLA images at 1.5 GHz, we have found evidence that

Michael Connelley, Bo Reipurth, Alan Tokunaga

We present the Class I protostellar binary separation distribution based on the data tabulated in the companion paper. We verify the excess of Class I binary stars over solar-type main-sequence stars, especially at separations beyond 500 AU. Although our sources are in nearby star forming regions distributed across the entire sky (including Orion), none of o

G. Akemann, P. H. Damgaard

Dirac operator eigenvalues split into two when subjected to two different external vector sources. In a specific finite-volume scaling regime of gauge theories with fermions, this problem can be mapped to a chiral Random Two-Matrix Theory. We derive analytical expressions to leading order in the associated finite-volume expansion, showing how individual Dira

Daniel Campos, Sergei Fedotov, Vicenç Méndez

In this paper we reconsider the Mass Action Law (MAL) for the anomalous reversible reaction $A\rightleftarrows B$ with diffusion. We provide a mesoscopic description of this reaction when the transitions between two states $A$ and $B$ are governed by anomalous (heavy-tailed) waiting-time distributions. We derive the set of mesoscopic integro-differential equ

Su Houng Lee, Marina Nielsen, Ulrich Wiedner

We use QCD sum rules to study the possible existence of a $D_s\bar{D}^*+ D_s^*\bar{D}$ molecule with the quantum number $J^P=1^+$. We consider the contributions of condensates up to dimension eight and work at leading order in $α_s$. We obtain $m_{D_sD^*}=(3.96\pm0.10) \GeV$ around 100 MeV above the mass of the meson X(3872). The proposed state is a natural

Kunihiko Yamauchi, Frank Freimuth, Stefan Blügel, Silvia Picozzi

The microscopic origin of the magnetically-driven ferroelectricity in collinear AFM-E orthorhombic manganites is explained by means of first-principles Wannier functions. We show that the polarization is mainly determined by the "asymmetric electron hopping" of orbitally-polarized Mn eg states, implicit in the peculiar in-plane zig-zag spin arrangeme

S. V. Barabash, V. Ozolins, C. Wolverton

Using a first-principles cluster expansion, we shed light on the solid-state phase diagram and structure of the recently discovered high-performance thermoelectrics, Pb-Ag-Sb-Te alloys. The observed nanoscale inhomogeneities are shown to be coherent precipitates of ordered (Ag)m(Sb)n(Te)m+n phases, such as AgSbTe2, all immiscible with rocksalt PbTe. The solu

Florian Marquardt, A. A. Clerk, S. M. Girvin

We review the quantum theory of cooling of a mechanical oscillator subject to the radiation pressure force due to light circulating inside a driven optical cavity. Such optomechanical setups have been used recently in a series of experiments by various groups to cool mechanical oscillators (such as cantilevers) by factors reaching $10^{5}$, and they may soon

B. G. Ueland, G. C. Lau, R. S. Freitas, J. Snyder

We have studied the thermodynamics of the stuffed spin ice material, Dy2(DyxTi2-x)O7-x/2, in which additional Dy3+ replace Ti4+ in the pyrochlore Dy2Ti2O7. Heat capacity measurements indicate that these materials lose the spin ice zero point entropy for x >= 0.3, sharply contrasting with results on the analogous Ho materials. A finite ac susceptibility is ob

C. Ciofi degli Atti, L. P. Kaptari, H. Morita

The interpretation of recent Jlab experimental data on the exclusive process A(e,e'p)B off few-nucleon systems are analyzed in terms of realistic nuclear wave functions and Glauber multiple scattering theory, both in its original form and within a generalized eikonal approximation. The relevance of the exclusive process 4He(e,e'p)^3H for possible inv

U. Baur, L. H. Orr

Many new physics models predict resonances with masses in the TeV range which decay into a pair of top quarks. With its large cross section, t-bar t production at the Large Hadron Collider (LHC) offers an excellent opportunity to search for such particles. We present a detailed study of the discovery potential of the CERN Large Hadron Collider for Kaluza-Kle

F. J. Rodriguez, L. Quiroga, C. Tejedor, M. D. Martin

We report on time-resolved photoluminescence from semiconductor microcavities showing that an optically controllable mechanism exists to turn on and off memory effects in a polariton system. By increasing the laser pumping pulse intensity we observe revivals of the decaying time-resolved photoluminescence signal, a manifestly non-Markovian behavior of the op

Gabor Schmera, Laszlo B. Kish

We analyze a (symmetrical) two-sensor arrangement with a joint boundary line between the sensors for fluctuation-enhanced sensing. We show a way to separate the adsorption-desorption signal components from the diffusive signal component. Thus the method generates two independent output spectra which doubles the sensor information for pattern recognition.

S. Dawson, M. Grazzini, A. Nikitenko, M. Schumacher

Report of the Working Group on Higgs Bosons for the Workshop, ``Physics at TeV Colliders'', Les Houches, France, 11-29 June, 2007.

A. Amador, N. Bagatella, R. Cordero, E. Rojas

We describe how to construct the dynamics of relativistic particles following, either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline

C. Ciofi degli Atti, L. P. Kaptari

The exclusive process 3He(e,e'p)2H has been analyzed by a non-factorized and parameter-free approach based upon realistic few-body wave functions corresponding to the $AV18$ interaction and treating the rescattering of the struck nucleon within a generalized eikonal approximation. The results of our calculations, compared with recent JLab experimental da

Alan R. White

SU(5) gauge theory with massless left-handed fermions in the representation 5+15+40+45* (QUD) may have a bound-state S-Matrix that, uniquely, contains the asymptotically unitary Critical Pomeron and which might also reproduce the full Standard Model. If so, QUD would provide an underlying unification for the Standard Model in which very similar massless ferm

J. B. Hutchings, C. Proulx

An asymmetry index is derived from ellipse-fitting to galaxy images, that gives weight to faint outer features and is not strongly redshift-dependent. These measures are made on a sample of 13 2MASS QSOs and their neighbour galaxies, and a control sample of field galaxies from the same wide-field imaging data. The QSO host galaxy asymmetries correlate well w

S. Esposito, O. Pisanti

We give a detailed account of the recent retrieval of a consistent amount (about 600 pages) of documents written by Enrico Fermi and/or his collaborators, coming from different sources previously unexplored. These documents include articles, patents, reports, notes on scientific and technical meetings and other papers, mainly testifying Fermi's activity

Nadia Fawaz, Keyvan Zarifi, Merouane Debbah, David Gesbert

We analyze a multi-level MIMO relaying system where a multiple-antenna transmitter sends data to a multipleantenna receiver through several relay levels, also equipped with multiple antennas. Assuming correlated fading in each hop, each relay receives a faded version of the signal transmitted by the previous level, performs precoding on the received signal a

Pierre Le Doussal, A. Alan Middleton, Kay Joerg Wiese

We study the minimum-energy configuration of a d-dimensional elastic interface in a random potential tied to a harmonic spring. As a function of the spring position, the center of mass of the interface changes in discrete jumps, also called shocks or "static avalanches''. We obtain analytically the distribution of avalanche sizes and its cumulant

Hidetsugu Seki, Kazusumi Ino

We numerically study the system of rapidly rotating Bose atoms at the filling factor (ratio of particle number to vortex number) $ν=1$ with the dipolar interaction. A moderate dipolar interaction stabilizes the incompressible quantum liquid at $ν=1$. Further addition induces a collapse of it. The state after the collapse is a compressible state which has pha

Krystyna Kuperberg, Kevin Gammon

The pseudo-circle is known to be nonhomogeneous. The original proofs of this fact were discovered independently by L. Fearnley and J.T. Rogers, Jr. The purpose of this paper is to provide an alternative, very short proof based on a result of D. Bellamy and W. Lewis.

Paolo Moretti, Lasse Laurson, Mikko J. Alava

The dynamics of dislocation assemblies in deforming crystals indicate the emergence of collective phenomena, intermittent fluctuations and strain avalanches. In polycrystalline materials, the understanding of plastic deformation mechanisms depends on grasping the role of grain boundaries on dislocation motion. Here the interaction of dislocations and elastic

S. Messina, E. Distefano, Padmakar Parihar, Y. B. Kang

Rotation and solar-type magnetic activity are closely related to each other in stars of G or later spectral types. Presence and level of magnetic activity depend on star's rotation and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the connection bet

J. O. Day, E. Brekke, T. G. Walker

Population dynamics in weakly-excited clouds of ultracold $^{87}$Rb Rydberg atoms were studied by means of trap loss, fluorescence detection, and state dependent stimulated emission. Rydberg atoms were excited to various nl Rydberg states via continuous two-photon excitation from a magneto-optical trap. A stimulated emission probe laser was then used to brin

Gustavo A. Lara, P. A. Orellana, E. V. Anda

Electron tunneling through a two stage Kondo system constituted by a double quantum-dot molecule side coupled to a quantum wire, under the effect of a finite external potential is studied. We found that $I$-$V$ characteristic shows a negative differential conductance region induced by the electronic correlation. This phenomenon is a consequence of the proper

Tomas Dahlen, Louis-Gregory Strolger, Adam G. Riess

We use the HST ACS imaging of the two GOODS fields during Cycles 11, 12, and 13 to derive the Type Ia supernova rate in four redshift intervals in the range 0.2<z<1.8. Compared to our previous results based on Cycle 11 observations only, we have increased the coverage of the search by a factor 2.7, making the total area searched equivalent to one square degr

Svante Janson

We exploit a bijection between plane recursive trees and Stirling permutations; this yields the equivalence of some results previously proven separately by different methods for the two types of objects as well as some new results. We also prove results on the joint distribution of the numbers of ascents, descents and plateaux in a random Stirling permutatio

Mathias Michel, Ortwin Hess, Hannu Wichterich, Jochen Gemmer

We investigate energy transport in several two-level atom or spin-1/2 models by a direct coupling to heat baths of different temperatures. The analysis is carried out on the basis of a recently derived quantum master equation which describes the nonequilibrium properties of internally weakly coupled systems appropriately. For the computation of the stationar

Erek Bilgici, Christof Gattringer

We represent the Polyakov loop correlator as a spectral sum of correlators of eigenvectors of the lattice Dirac operator. This spectral representation is studied numerically using quenched SU(3) configurations below and above the deconfinement temperature. We analyze whether the individual Dirac eigenvector correlators differ in the confined and deconfined p

Odinette Renée Abib

We shall study the equivalence problem for ordinary differential equations with respect to the affine transformations group.

Eric Braaten, Lucas Platter

The momentum distribution in a Fermi gas with two spin states and a large scattering length has a tail that falls off like 1/k^4 at large momentum k, as pointed out by Shina Tan. He used novel methods to derive exact relations between the coefficient of the tail in the momentum distribution and various other properties of the system. We present simple deriva

Tim Dokchitser, Vladimir Dokchitser

Let E be an elliptic curve defined over a number field K. Michael Larsen conjectured that for any finitely generated subgroup G of Gal(\bar K/K), the Mordell-Weil rank of E is unbounded in number fields fixed by G. We prove that the conjecture holds over K=Q for both the analytic rank and the p-infinity Selmer rank of E for every odd prime p. For arbitrary E

B. V. Novikov

This article is a survey of 0-cohomology of semigroups. The main attention is devoted to applications.

Ludovic Margerin, Michel Campillo, Bart Van Tiggelen, Renaud Hennino

We have studied the partition of shear, compressional and kinetic energies in the coda of ten earthquakes recorded on a dense array, located at Pinyon Flats Observatory (PFO), California. We observe a clear stabilization of the shear to compressional ($W^s/W^p$) energy ratio in the coda, with an average value of about 2.8. The ratio between the vertical and

Ramanpreet Kaur, Biswajit Paul, Brijesh Kumar, Ram Sagar

We have investigated multiband optical photometric variability and stability of the H$α$ line profile of the transient X-ray binary IGR J01583+6713. We set an upper limit of 0.05 mag on photometric variations in the {\it V} band over a time scale of 3 months. The H$α$ line is found to consist of non-Gaussian profile and quite stable for a duration of 2 month

Olivier Lopez

In this article, we propose some new generalizations of M-estimation procedures for single-index regression models in presence of randomly right-censored responses. We derive consistency and asymptotic normality of our estimates. The results are proved in order to be adapted to a wide range of techniques used in a censored regression framework (e.g. syntheti

Abedelaziz Mohaisen, DaeHun Nyang, KyungHee Lee

The security of wireless sensor networks is an active topic of research where both symmetric and asymmetric key cryptography issues have been studied. Due to their computational feasibility on typical sensor nodes, symmetric key algorithms that use the same key to encrypt and decrypt messages have been intensively studied and perfectly deployed in such envir

Daouda Niang Diatta, Bernard Mourrain, Olivier Ruatta

An algorithm is presented for the computation of the topology of a non-reduced space curve defined as the intersection of two implicit algebraic surfaces. It computes a Piecewise Linear Structure (PLS) isotopic to the original space curve. The algorithm is designed to provide the exact result for all inputs. It&#39;s a symbolic-numeric algorithm based on sub

Jean-Louis Nicolas

Let us denote by $τ(n)$ and $\si(n)$ the number and the sum of the divisors of $n$ and by $\vfi$ Euler&#39;s function. We give effective upper bounds for $\frac{n}{\vfi(n)}$ in terms of $\vfi(n)$, and for $\frac{\si(n)}{n}$ in terms of $τ(n)$.

Shinji Tsujikawa, Kotub Uddin, Shuntaro Mizuno, Reza Tavakol

We construct a family of viable scalar-tensor models of dark energy (DE) which possess a phase of late-time acceleration preceded by a standard matter era, while at the same time satisfying the local gravity constraints (LGC). The coupling Q between the scalar field and the non-relativistic matter in the Einstein frame is assumed to be constant in our scenar

Michael Schulz, Steffen Trimper

An exact expression for the Drude conductivity in one dimension is derived under the presence of an arbitrary potential. In getting the conductivity the influence of the electric field on the crystal potential is taken into account. This coupling leads to a systematic deformation of the potential and consequently to a significant modification of the charge t

Michael Hahsler

With customer relationship management (CRM) companies move away from a mainly product-centered view to a customer-centered view. Resulting from this change, the effective management of how to keep contact with customers throughout different channels is one of the key success factors in today&#39;s business world. Company Web sites have evolved in many indust

O. V. Dolgov, A. A. Golubov

We discuss the effects of anisotropy on superconducting critical temperature and order parameter in a strongly coupled regime. The multiband representation is used as a model for anisotropy. We show that strong coupling effects in multiband superconductors lead to pair-breaking due to interband coupling because soft phonon modes play the same role as usual i

Pei-Qing Jin, You-Quan Li

Starting from a continuum constituted by charged tops, we formulate the classical counterpart of a previously obtained covariant continuity-like equation for the spin current. Such a formulism provides an intuitive picture to elucidate the non-conservation of the spin current and to interpret the condition for the emergence of an infinite spin relaxation tim

P. D. Gujrati

The irreversibility in a statistical system is traced to its probabilistic evolution, and the molecular chaos assumption is not its unique consequence as is commonly believed. Under the assumption that the rate of change of the each microstate probability vanishes only as time diverges, we prove that the entropy of a system at constant energy cannot decrease

Lorenzo Zaninetti

The search for a luminosity function for galaxies both alternative or companion to a Schechter function is a key problem in the reduction of data from catalogs of galaxies. Two luminosity functions for galaxies can be built starting from two distributions of mass as given by the fragmentation. A first overall distribution function is the Kiang function that

J. M. Paredes

The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259-63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides a clear evidence of very efficient acceleration of particles to multi-TeV energies in X-ray binaries. These observations demonstrate the richness of non-thermal phenomena in compact galac

Valentin Savin

Algebraic-geometric codes can be constructed by evaluating a certain set of functions on a set of distinct rational points of an algebraic curve. The set of functions that are evaluated is the linear space of a given divisor or, equivalently, the set of section of a given line bundle. Using arbitrary rank vector bundles on algebraic curves, we propose a natu

Bjoern Malte Schäfer

In this paper I investigate the family of mixed three-point correlation functions <tau^q gamma^{3-q}>, q=0,1,2, between the integrated Sachs-Wolfe (iSW) temperature perturbation tau and the galaxy overdensity gamma as a tool for detecting the gravitational interaction of cosmic microwave background (CMB) photons with the potentials of nonlinearly evolving co

Chris Allton, Michael Teper, Aurora Trivini

Interpreting the way that the SU(3) bare lattice coupling runs with the lattice spacing is complicated by the fact that there is a smooth cross-over region in which the strong coupling expansion transforms into a weak-coupling one. For N > 4, however, there is a first order bulk transition that cleanly separates the strong and weak coupling regimes. We find

V. V. Korostelev

An introduction in quantum mechanical theory for NMR students which covers basic concepts and calculations.

Pedro Ramos, Raquel Viaña

Neumann-Lara and Urrutia showed in 1985 that in any set of n points in the plane in general positionthere is always a pair of points such that any circle through them contains at least (n-2)/60 points. In a series of papers, this result was subsequently improved till n/4.7, which is currently the best known lower bound. In this paper we propose a new approac