September 2007 arXiv papers — page 13

G. Maier

VERITAS is an atmospheric Cherenkov telescope array designed to study astrophysi cal sources of very-high-energy gamma radiation. Located in southern Arizona, USA, the array consists of four 12m-diameter imaging Cherenkov telescopes. All four telescopes have been deployed at the basecamp of the Whipple Observatory and began full operation in early 2007. This

V. A. Khodel

Two different scenarios of the quantum critical point (QCP), a zero-temperature instability of the Landau state, related to the divergence of the effective mass, are investigated. Flaws of the standard scenario of the QCP, where this divergence is attributed to the occurrence of some second-order phase transition, are demonstrated. Salient features of a diff

Nikodem J. Poplawski

A general affine connection has enough degrees of freedom to describe the classical gravitational and electromagnetic fields in the metric-affine formulation of gravity. The gravitational field is represented in the Lagrangian by the symmetric part of the Ricci tensor and the classical electromagnetic field can be represented by the tensor of homothetic curv

Simone Severini, Ferenc Szöllősi

Strongly quadrangular matrices have been introduced in the study of the combinatorial properties of unitary matrices. It is known that if a (0, 1)-matrix supports a unitary then it is strongly quadrangular. However, the converse is not necessarily true. In this paper, we fully classify strongly quadrangular matrices up to degree 5. We prove that the smallest

Giovanni Coppola

We study the arithmetic (real) function f=g*1, with g &#34;essentially bounded&#34; and supported over the integers of [1,Q]. In particular, we obtain non-trivial bounds, through f &#34;correlations&#34;, for the &#34;Selberg integral&#34; and the &#34;symmetry integral&#34; of f in almost all short intervals [x-h,x+h], N<x<2N, beyond the &#34;classical&#34;

Nicholas J. Linesch, Raissa M. D&#39;Souza

The Biham-Middleton-Levine model (BML) is simple lattice model of traffic flow, self-organization and jamming. Rather than a sharp phase transition between free-flow and jammed, it was recently shown that there is a region where stable intermediate states exist, with details dependent on the aspect ratio of the underlying lattice. Here we investigate square

Sanjeevi Krishnan

As a practical foundation for a homotopy theory of abstract spacetime, we extend a category of certain compact partially ordered spaces to a convenient category of locally preordered spaces. In particular, we show that our new category is Cartesian closed and that the forgetful functor to the category of compactly generated spaces creates all limits and coli

Kyosuke Tsumura, Teiji Kunihiro

We propose a stable first-order relativistic dissipative hydrodynamic equation in the particle frame (Eckart frame) for the first time. The equation to be proposed was in fact previously derived by the authors and a collaborator from the relativistic Boltzmann equation. We demonstrate that the equilibrium state is stable with respect to the time evolution de

Su Houng Lee, Kazuaki Ohnishi, Shigehiro Yasui, In-Kwon Yoo

We propose the enhancement of $Λ_{c}$ as a novel QGP signal in heavy ion collisions at RHIC and LHC. Assuming a stable bound diquark state in the strongly coupled QGP near the critical temperature, we argue that the direct two-body collision between a $c$ quark and a $[ud]$ diquark would lead to an enhanced $Λ_{c}$ production in comparison with the normal th

J. Lavalle, Q. Yuan, D. Maurin, X. -J. Bi

Anti-proton and positron Galactic cosmic ray spectra are among the key targets for indirect detection of dark matter. The boost factors, corresponding to an enhancement of the signal and linked to the clumpiness properties of the dark matter distribution, have been taken as high as thousands in the past. The dramatic impact of these boost factors for indirec

Emeterio Navarro, Ruben Cantero, Joao Rodrigues, Frank Schweitzer

We present analytical investigations of a multiplicative stochastic process that models a simple investor dynamics in a random environment. The dynamics of the investor&#39;s budget, $x(t)$, depends on the stochasticity of the return on investment, $r(t)$, for which different model assumptions are discussed. The fat-tail distribution of the budget is investi

Hirokazu Nishimura

Lie algebroids are by no means natural as an infinitesimal counterpart of groupoids. In this paper we propose a functorial construction called Nishimura algebroids for an infinitesimal counterpart of groupoids. Nishimura algebroids, intended for differential geometry, are of the same vein as Lawvere&#39;s functorial notion of algebraic theory and Ehresmann&#

Xiaodi Wu, Runyao Duan

We study the unsorted database search problem with items $N$ from the viewpoint of unitary discrimination. Instead of considering the famous $O(\sqrt{N})$ Grover&#39;s the bounded-error algorithm for the original problem, we seek for the results about the exact algorithms, i.e. the ones succeed with certainty. Under the standard oracle model $\sum_j (-1)^{δ_

Matthias Habl, Werner Wegscheider

A quantum Hall system which is divided into two laterally coupled subsystems by means of a tunneling barrier exhibits a complex Landau level dispersion. Magnetotunneling spectroscopy is employed to investigate the small energy gaps which separate subsequent Landau bands. The control on the Fermi level permits to trace the anticrossings for varying magnetic f

Plamen G. Krastev, Bao-An Li, Aaron Worley

Properties, structure, and thermal evolution of neutron stars are determined by the equation of state of stellar matter. Recent data on isospin-diffusion and isoscaling in heavy-ion collisions at intermediate energies as well as the size of neutron skin in $^{208}Pb$ have constrained considerably the density dependence of the nuclear symmetry energy and, in

Ahmad Sheykhi

A class of $(n+1)$-dimensional topological black hole solutions in Einstein-Maxwell-dilaton theory with Liouville-type potentials for the dilaton field is presented. In these spacetimes, black hole horizon and cosmological horizon can be an $(n-1)$-dimensional positive, zero or negative constant curvature hypersurface. Because of the presence of the dilaton

Yun Song, Liang-Jian Zou

The nondegenerate two-orbital Hubbard model is studied within the dynamic mean-field theory to reveal the influence of two important factors, i.e. crystal field splitting and interorbital hopping, on orbital selective Mott transition (OSMT) and realistic compound Ca$_{2-x}$Sr$_{x}$RuO$_{4}$. A distinctive feature of the optical conductivity of the two nondeg

A. Iucci, C. J. Bolech

We present in detail the bosonization-refermionization solution of the anisotropic version of the two-channel Anderson model at a particular manifold in the space of parameters of the theory, where we establish an equivalence with a Fermi-Majorana bi-resonant level model. The correspondence is rigorously proved by explicitly constructing the new fermionic fi

Matvei Libine

These are the lecture notes for the introductory graduate course I taught at Yale during Spring 2007. I mostly followed [GS], [BGV], [AB], [Par2], and there are no original results in these notes.

Chulhoon Chang, Alexander Konopelko, Wei Cui

Many of the recently discovered TeV gamma-ray sources are associated with pulsar wind nebulae (PWNe). In fact, they represent the most populous class of Galactic sources at TeV energies. In addition, HESS has also discovered, in a survey of the Galactic plane, a population of TeV gamma-ray sources that are still without definitive counterparts at longer wave

Thomas R. Weikl, Reinhard Lipowsky

We review theoretical results for the adhesion-induced phase behavior of biomembranes. The focus is on models in which the membranes are represented as discretized elastic sheets with embedded adhesion molecules. We present several mechanism that lead to the formation of domains during adhesion, and discuss the time-dependent evolution of domain patterns obt

Aditya Mahajan, Demosthenis Teneketzis

We consider a real-time communication system with noisy feedback consisting of a Markov source, a forward and a backward discrete memoryless channels, and a receiver with finite memory. The objective is to design an optimal communication strategy (that is, encoding, decoding, and memory update strategies) to minimize the total expected distortion over a fini

Andreea Iordan, Alain Duperray, Claude Verdier

Results on the rheological behavior of novel CHO cell suspensions in a large range of concentrations are reported. The concentration dependent yield stress and elastic plateau modulus are formalized in the context of fractal aggregates under shear, and quite different exponents are found as compared to the case of red blood cell suspensions. This is explaine

Yi-Zen Chu, Tanmay Vachaspati

We find the full spectrum of fermion bound states on a Z_2 kink. In addition to the zero mode, there are int[2 m_f/m_s] bound states, where m_f is the fermion and m_s the scalar mass. We also study fermion modes on the background of a well-separated kink-antikink pair. Using a variational argument, we prove that there is at least one bound state in this back

Harold Blas

We consider the sl(3,C) affine Toda model coupled to matter (Dirac spinor) (ATM) and through a gauge fixing procedure we obtain the classical version of the generalized sl(3,C) sine-Gordon model (cGSG) which completely decouples from the Dirac spinors. The GSG models are multifield extensions of the ordinary sine-Gordon model. In the spinor sector we are lef

Bing Qi, Lei-Lei Huang, Li Qian, Hoi-Kwong Lo

In this paper, we present a fully fiber-based one-way Quantum Key Distribution (QKD) system implementing the Gaussian-Modulated Coherent States (GMCS) protocol. The system employs a double Mach-Zehnder Interferometer (MZI) configuration in which the weak quantum signal and the strong Local Oscillator (LO) go through the same fiber between Alice and Bob, and

Pierre Colin

The giant radio galaxy M87 is the only extragalactic non-blazar object which has been detected as a source of very high energy gamma-rays. It represents a unique opportunity to study the phenomena of gamma-ray emission from a nearby AGN. In this paper we report preliminary results from the observations of M87 taken with the imaging atmospheric Cherenkov tele

Gernot Maier

The high mass X-ray binary LS I +61 303 has been observed over several months in 2006 and 2007 with the VERITAS array of imaging air-Cherenkov telescopes. A signal of high energy gamma rays with energies above 350 GeV is detected in several orbital cycles of the binary system. The detected flux of gamma rays is strongly variable with the orbital period of 26

S. J. Fegan

VERITAS, the Very Energetic Radiation Telescope Imaging Array System, is an array of four imaging Atmospheric Cherenkov telescopes in southern Arizona. It is sensitive to gamma rays at energies above 100 GeV. Here, we discuss the results of observations of two well known VHE blazars, Markarian 421 and Markarian 501, during Spring 2006 which were made with th

Pascal Fortin

The VERITAS collaboration has observed the high-frequency-peaked BL Lac object 1ES 1218+304 using an array of several imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in Southern Arizona. A gamma-ray signal was detected with high significance for the observations taken during several months in the 2006-2007 observing season. Here

H. Xiao, T. Hu, T. A. Sayles, M. B. Maple

Torque and magnetization measurements in magnetic fields $H$ up to 14 T were performed on CeCoIn$_5$ single crystals. The amplitude of the paramagnetic torque shows an $H^{2.3}$ dependence in the mixed state and an $H^{2}$ dependence in the normal state. In addition, the mixed-state magnetizations for both $H\parallel c$ and $H\parallel ab$ axes show anomalo

Antonio Sa Barreto

We prove a support theorem for the radiation fields on asymptotically Euclidean manifolds with metrics which are warped products near infinity. It generalizes to this setting the well known support theorem for the Radon transform on n-dimensional Euclidean space.

X. S. Chen, X. F. Lü, W. M. Sun, F. Wang

This two-paper series addresses and fixes the long-standing gauge invariance problem of angular momentum in gauge theories. This QED part reveals: 1) The spin and orbital angular momenta of electrons and photons can all be consistently defined gauge invariantly. 2) These gauge-invariant quantities can be conveniently computed via the canonical, gauge-depende

Elena Belsole, Andrew C. Fabian

One of the most promising solutions for the cooling flow problem involves energy injection from the central AGN. However it is still not clear how collimated jets can heat the ICM at large scale, and very little is known concerning the effect of radio lobe expansion as they enter into pressure equilibrium with the surrounding cluster gas. Cygnus A is one of

Y. I. Izotov, T. X. Thuan, N. G. Guseva

We present spectra of a large sample of low-metallicity blue compact dwarf galaxies which exhibit broad components in their strong emission lines, mainly in Hbeta, [O III]4959, 5007 and Halpha. Twenty-three spectra have been obtained with the MMT, 14 of which show broad emission. The remaining 21 spectra with broad emission have been selected from the Data R

Fabrice Rossi, Brieuc Conan-Guez

In this paper, we study a natural extension of Multi-Layer Perceptrons (MLP) to functional inputs. We show that fundamental results for classical MLP can be extended to functional MLP. We obtain universal approximation results that show the expressive power of functional MLP is comparable to that of numerical MLP. We obtain consistency results which imply th

Fabrice Rossi, Nicolas Delannay, Brieuc Conan-Guez, Michel Verleysen

Functional Data Analysis (FDA) is an extension of traditional data analysis to functional data, for example spectra, temporal series, spatio-temporal images, gesture recognition data, etc. Functional data are rarely known in practice; usually a regular or irregular sampling is known. For this reason, some processing is needed in order to benefit from the smo

Damien François, Fabrice Rossi, Vincent Wertz, Michel Verleysen

Combining the mutual information criterion with a forward feature selection strategy offers a good trade-off between optimality of the selected feature subset and computation time. However, it requires to set the parameter(s) of the mutual information estimator and to determine when to halt the forward procedure. These two choices are difficult to make becau

Fabrice Rossi, Damien François, Vincent Wertz, Marc Meurens

The large number of spectral variables in most data sets encountered in spectral chemometrics often renders the prediction of a dependent variable uneasy. The number of variables hopefully can be reduced, by using either projection techniques or selection methods; the latter allow for the interpretation of the selected variables. Since the optimal approach o

Aram Apyan, Armen Apyan, Michael Schmitt

It is well established that neutrinos have mass, yet it is very difficult to measure those masses directly. Within the standard model of particle physics, neutrinos will have an intrinsic magnetic moment proportional to their mass. We examine the possibility of detecting the magnetic moment using a conducting loop. According to Faraday&#39;s Law of Induction

Elena Belsole, Diana M. Worrall, Martin J. Hardcastle, Judith H. Croston

We investigate the properties of the environment around 20 powerful radio galaxies and quasars at redshifts between 0.45 and 1. Using XMM-Newton and Chandra observations we probe the spatial distribution and the temperature of the cluster gas. We find that more than 60 per cent of powerful radio sources in the redshift range of our sample lie in a cluster of

R. Salinas, T. Richtler, A. J. Romanowsky, M. J. West

Context:Struble (1988) found what appeared to be a cD halo without cD galaxy in the center of the galaxy cluster Abell 545. This remarkable feature has been passed almost unnoticed for nearly twenty years. Aims:Our goal is to review Struble&#39;s claim by providing a first (preliminary) photometric and spectroscopic analysis of this &#39;&#39;star pile&#39;&

N. B. Christensen, H. M. Ronnow, D. F. McMorrow, A. Harrison

Bulk magnetism in solids is fundamentally quantum mechanical in nature. Yet in many situations, including our everyday encounters with magnetic materials, quantum effects are masked, and it often suffices to think of magnetism in terms of the interaction between classical dipole moments. Whereas this intuition generally holds for ferromagnets, even as the si

Kanetomo Sato

In this paper, we prove the $\ell$-adic abelian class field theory for henselian regular local rings of equi-characteristic assuming the surjectivity of Galois symbol maps, which is a $\ell$-adic variant of a result of Matsumi [13].

Yu. Yu. Tarasevich, V. A. Cherkasova

We consider site percolation of dimers (``neadles&#39;&#39;) on simple cubic lattice. The percolation threshold is estimated as $p_c^\text{perc} \approx 0.2555 \pm 0.0001$. The jamming threshold is estimated as $p_c^\text{jamm} = 0.799 \pm 0.002$.

Olivier Mousis, Francoise Pauzat, Yves Ellinger, Cecilia Ceccarelli

We study the efficiency of the noble gases sequestration by the ion H3+ in the form of XH3+ complexes (with X = argon, krypton or xenon) in gas phase conditions similar to those encountered during the cooling of protoplanetary disks, at the epoch of icy planetesimals formation. We show that XH3+ complexes form very stable structures in the gas phase and that

A. Bina, K. Atazadeh, S. Jalalzadeh

We consider the effects of noncommutativity and the generalized uncertainty principle on the FRW cosmology with a scalar field. We show that, the cosmological constant problem and removability of initial curvature singularity find natural solutions in this scenarios.

Dongni Tan

In order to generalize the results of Mazur-Ulam and Vogt, we shall prove that any map T which preserves equality of distance with T(0)=0 between two F-spaces without surjective condition is linear. Then, as a special case linear isometries are characterized through a simple property of their range.

C. W. Walter

Uncertainties in knowledge of neutrino interactions directly impact the ability to measure the parameters of neutrino oscillation. Experiments which make use of differing technologies and neutrino beams are sensitive to different uncertainties. Several experimental and theoretical issues are reviewed.

Calin Chindris

For the Kronecker quiver, Zwara has found an example of a representation whose orbit closure is neither unibranch nor Cohen-Macaulay. In this note, we explain how to extend this example to all infinite type quivers without oriented cycles.

Asish Satpathy

The CMS experiment at the LHC features the largest Silicon Strip Detector ever built. The impact of the operating conditions and physics requirements on the design choices of the CMS Silicon Tracker is reviewed. The readiness of the Silicon Strip Tracker for the tentatively scheduled CMS commissioning in Summer 2008 is briefly described.

Nawaf Bou-Rabee, Houman Owhadi

Stochastic variational integrators for constrained, stochastic mechanical systems are developed in this paper. The main results of the paper are twofold: an equivalence is established between a stochastic Hamilton-Pontryagin (HP) principle in generalized coordinates and constrained coordinates via Lagrange multipliers, and variational partitioned Runge-Kutta

Michael Assaf, Baruch Meerson

We find that discrete noise of inhibiting (signal) molecules can greatly delay the extinction of plasmids in a plasmid replication system: a prototypical biochemical regulatory network. We calculate the probability distribution of the metastable state of the plasmids and show on this example that the reaction rate equations may fail in predicting the average

Panos Aliferis

The threshold estimate derived in previous versions of this paper was incorrect; this note explains the flaw. A new proof is discussed in arXiv:0809.5063.

Romyar T. Sharifi

For primes p greater than 3, we propose a conjecture that relates the values of cup products in the Galois cohomology of the maximal unramified outside p extension of a cyclotomic field on cyclotomic p-units to the values of p-adic L-functions of cuspidal eigenforms that satisfy mod p congruences with Eisenstein series. Passing up the cyclotomic and Hida tow

C. Nadir Kaplan, A. Nihat Berker

The spin-1/2 quantum Heisenberg model is studied in all spatial dimensions d by renormalization-group theory. Strongly asymmetric phase diagrams in temperature and antiferromagnetic bond probability p are obtained in dimensions d \geq 3. The asymmetry at high temperatures approaching the pure ferromagnetic and antiferromagnetic systems disappears as d is inc

F. Pauly, J. K. Viljas, J. C. Cuevas

We study theoretically the length dependence of both conductance and thermopower in metal-molecule-metal junctions made up of dithiolated oligophenylenes contacted to gold electrodes. We find that while the conductance decays exponentially with increasing molecular length, the thermopower increases linearly as suggested by recent experiments. We also analyze

Andreas Fischer, Paolo Sibani, Karl Heinz Hoffmann

We numerically simulate a thermalization process in an energy landscape with hierarchically organized metastable states. The initial configuration is chosen to have a large energy excess, relative to the thermal equilibrium value at the running temperature. We show that the initial energy surplus is dissipated in a series of intermittent bursts, or quakes, w

Michael Taylor, Angeles I. Diaz, Lucas A. Jodar-Sanchez, Rafael J. Villanueva-Mico

On the verge of the centenary of dimensional analysis (DA), we present a generalisation of the theory and a methodology for the discovery of empirical laws from observational data. It is well known that DA: a) reduces the number of free parameters, b) guarantees scale invariance through dimensional homogeneity and c) extracts functional information encoded i

Andreas Alvermann, Holger Fehske

We propose a new concept for the dynamics of a quantum bath, the Chebyshev space, and a new method based on this concept, the Chebyshev space method. The Chebyshev space is an abstract vector space that exactly represents the fermionic or bosonic bath degrees of freedom, without a discretization of the bath density of states. Relying on Chebyshev expansions

Pio J. Arias, Rolando Gaitan Deveras

The Lagrangian constraint analysis of the selfdual massive spin 2 theory in a 2+1 dimensional flat space-time and its extension to a curved one, are performed. Demanding consistence of degrees of freedom in the model with gravitational interaction, gives rise to physical restrictions on non minimal coupling terms and background. Finally, a constant curvature

Mauricio Martinez, Michael Strickland

We calculate the medium dilepton yield from a quark-gluon plasma which has a time-dependent local momentum-space anisotropy. A phenomenological model for the hard momentum scale, p_hard(tau), and plasma anisotropy parameter, xi(tau), is constructed which interpolates between free streaming behavior at early times (tau << tau_iso) and ideal hydrodynamic behav

Matthias Lenz

In dieser Diplomarbeit werden einige Gradschranken für Erzeugendensysteme und Gröbnerbasen von torischen Idealen von Flusspolytopen bewiesen. Alle torischen Ideale von Flusspolytopen sind im Grad 3 erzeugt. Glatte (3x4)-Transportpolytope sind sogar im Grad 2 erzeugt. Die reduzierte Gröbnerbasis eines beliebigen (m \times n)-Transportpolytops bezüglich einer

V. M. Red&#39;kov, A. A. Bogush, N. G. Tokarevskaya

Parametrization of complex 4 x 4 - matrices G in terms of Dirac tensor parameters (A,B,A_{l},B_{l},F_{kl}) or equivalent four complex 4-vectors (k,m,n,l) is investigated. In the given parametrization, the problem of inverting any 4 x 4 matrix G is solved. Expression for determinant of any matrix G is found: det G = F(k,m,n,l).

Hyeong-Chan Kim, Jae-Weon Lee, Jungjai Lee

We discuss the identity of black hole entropy and show that the first law of black hole thermodynamics, in the case of a Schwarzschild black hole, can be derived from Landauer&#39;s principle by assuming that the black hole is one of the most efficient information erasers in systems of a given temperature. The term &#34;most efficient&#34; implies that minim

Adi Nusser

We present a simplified dynamical model of the ``Bullet&#39;&#39; system of two colliding clusters. The model constrains the masses of the system by requiring that the orbits of the main and sub components satisfy the cosmological initial conditions of vanishing physical separation a Hubble time ago. This is also known as the timing argument. The model consi

Rong-Gen Cai, Li-Ming Cao, Ya-Wen Sun

We show that the confinement-deconfinement phase transition of supersymmetric Yang-Mills theories with 16 supercharges in various dimensions can be realized through the Hawking-Page phase transition between the near horizon geometries of black Dp-branes and BPS Dp-branes by removing a small radius region in the geometry in order to realize a confinement phas

Elaine M. Sadler, Roberto Ricci, Ronald D. Ekers, Robert J. Sault

We have used the Australia Telescope Compact Array (ATCA) at 95GHz to carry out continuum observations of 130 extragalactic radio sources selected from the Australia Telescope 20GHz (AT20G) survey. Over 90% of these sources are detected at 95 GHz, and we use a triple-correlation method to measure simultaneous 20 and 95 GHz flux densities. We show that the AT

Ben Green, Terence Tao

A theorem of Leibman asserts that a polynomial orbit $(g(1),g(2),g(3),\ldots)$ on a nilmanifold $G/Γ$ is always equidistributed in a union of closed sub-nilmanifolds of $G/Γ$. In this paper we give a quantitative version of Leibman&#39;s result, describing the uniform distribution properties of a finite polynomial orbit $(g(1),\ldots,g(N))$ in a nilmanifold.

M. C. Babiuc, S. Husa, D. Alic, I. Hinder

We discuss results that have been obtained from the implementation of the initial round of testbeds for numerical relativity which was proposed in the first paper of the Apples with Apples Alliance. We present benchmark results for various codes which provide templates for analyzing the testbeds and to draw conclusions about various features of the codes. Th

Assaf Shomer

We present a short and intuitive argument explaining why gravity is non-renormalizable. The argument is based on black-hole domination of the high energy spectrum of gravity and not on the standard perturbative irrelevance of the gravitational coupling. This is a pedagogical note, containing textbook material that is widely appreciated by experts and is by n

N. Barbosa-Cendejas, A. Herrera-Aguilar, M. A. Reyes, C. Schubert

We study the properties of a previously found family of thick brane configurations in a pure geometric Weyl integrable 5D space time, a non-Riemannian generalization of Kaluza-Klein (KK) theory involving a geometric scalar field. Thus the 5D theory describes gravity coupled to a self-interacting scalar field which gives rise to the structure of the thick bra

Che-Ming Li, Der-San Chuu, Yueh-Nan Chen

We analyze the correlation structure of bipartite arbitrary-dimensional Bell inequalities via novel conditions of correlations in terms of differences of joint probabilities called correlators. The conditions of correlations are shown to be necessary for the multi-level Bell state. In particular, we find that the bipartite arbitrary-dimensional Bell-type ine

Michael Galperin, Abraham Nitzan, Mark A. Ratner

The influence of molecular vibration on the Seebeck coefficient is studied within a simple model. Results of a scattering theory approach are compared to those of a full self-consistent non-equilibrium Green&#39;s function scheme. We show, for a reasonable choice of parameters, that inelastic effects have non-negligible influence on the resulting Seebeck coe

Murat Cetinbas, Joshua Wilkie

We consider a system interacting with a chaotic thermodynamic bath. We derive an explicit and exact Kraus operator sum representation (OSR) for the open system reduced density. The OSR preserves the Hermiticity, complete positivity and norm. We show that it is useful as a numerical tool by testing it against exact results for a qubit interacting with an isol

K. Marinov, A. D. Boardman, V. A. Fedotov, N. Zheludev

It is shown that a new type of metamaterial, a 3D-array of toroidal solenoids, displays a significant toroidal response that can be readily measured. This is in sharp contrast to materials that exist in nature, where the toroidal component is weak and hardly measurable. The existence of an optimal configuration, maximizing the interaction with an external el

Carl M. Bender, Hugh F. Jones

The coupling of non-Hermitian PT-symmetric Hamiltonians to standard Hermitian Hamiltonians, each of which individually has a real energy spectrum, is explored by means of a number of soluble models. It is found that in all cases the energy remains real for small values of the coupling constant, but becomes complex if the coupling becomes stronger than some c

Mathieu Coppey, Alexander M. Berezhkovskii, Stuart C. Sealfon, Stanislav Y. Shvartsman

A model of autocrine signaling in cultures of suspended cells is developed on the basis of the effective medium approximation. The fraction of autocrine ligands, the mean and distribution of distances traveled by paracrine ligands before binding, as well as the mean and distribution of the ligand lifetime are derived. Interferon signaling by dendritic immune

A. V. Alexeevski, S. M. Natanzon

Analogue of classical Hurwitz numbers is defined in the work for regular coverings of surfaces with marked points by seamed surfaces. Class of surfaces includes surfaces of any genus and orientability, with or without boundaries; coverings may have certain singularities over the boundary and marked points. Seamed surfaces introduced earlier are not actually

G. Koch, N. Nadirashvili, G. Seregin, V. Sverak

We study bounded ancient solutions of the Navier-Stokes equations. These are the solutions which are defined for all past time. In two space dimensions we prove that such solutions are either constant or functions of time only, depending on the exact definition of admissible solutions. The general three dimensional problem seems to be out of reach of existin

Arnaud Durand

We study the size properties of a general model of fractal sets that are based on a tree-indexed family of random compacts and a tree-indexed Markov chain. These fractals may be regarded as a generalization of those resulting from the Moran-like deterministic or random recursive constructions considered by various authors. Among other applications, we consid

Arnaud Durand

We study the global and local regularity properties of random wavelet series whose coefficients exhibit correlations given by a tree-indexed Markov chain. We determine the law of the spectrum of singularities of these series, thereby performing their multifractal analysis. We also show that almost every sample path displays an oscillating singularity at almo

Arnaud Durand

We completely describe the size and large intersection properties of the Holder singularity sets of Levy processes. We also study the set of times at which a given function cannot be a modulus of continuity of a Levy process. The Holder singularity sets of the sample paths of certain random wavelet series are investigated as well.

Arnaud Durand

We investigate the size and large intersection properties of $$E_{t}=\{x\in\R^d \:|\: \|x-k-x_{i}\|<{r_{i}}^t\text{for infinitely many}(i,k)\in I^{μ,α}\times\Z^d\},$$ where $d\in\N$, $t\geq 1$, $I$ is a denumerable set, $(x_{i},r_{i})_{i\in I}$ is a family in $[0,1]^d\times (0,\infty)$ and $I^{μ,α}$ denotes the set of all $i\in I$ such that the $μ$-mass of t

Ishmael S. Msiza, Mehmood Haffejee

The protection of any electrical installation is one of the most important considerations in the field of electrical engineering. The electrical installation should be protected against hazards such as overload current and short circuit current conditions. The protection devices studied in this paper are the Miniature Circuit Breaker (MCB) and the High Ruptu

S. Pakuliak, V. Rubtsov, A. Silantyev

In this paper we discuss classical elliptic current algebras and show that there are two different choices of commutative test function algebras on a complex torus leading to two different elliptic current algebras. Quantization of these classical current algebras give rise to two classes of quantized dynamical quasi-Hopf current algebras studied by Enriquez

Aïcha El Golli, Brieuc Conan-Guez, Fabrice Rossi

In data analysis new forms of complex data have to be considered like for example (symbolic data, functional data, web data, trees, SQL query and multimedia data, ...). In this context classical data analysis for knowledge discovery based on calculating the center of gravity can not be used because input are not $\mathbb{R}^p$ vectors. In this paper, we pres

Aïcha El Golli, Fabrice Rossi, Brieuc Conan-Guez, Yves Lechevallier

Many data analysis methods cannot be applied to data that are not represented by a fixed number of real values, whereas most of real world observations are not readily available in such a format. Vector based data analysis methods have therefore to be adapted in order to be used with non standard complex data. A flexible and general solution for this adaptat

Sébastien Tremblay, Pavel Winternitz

All finite-dimensional indecomposable solvable Lie algebras $L(n,f)$, having the triangular algebra T(n) as their nilradical, are constructed. The number of nonnilpotent elements $f$ in $L(n,f)$ satisfies $1\leq f\leq n-1$ and the dimension of the Lie algebra is $\dim L(n,f)=f+{1/2}n(n-1)$.

A. D. Alhaidari

We obtain analytic solution of the time-independent Schrodinger equation in two dimensions for a charged particle moving in the field of an electric quadrupole. The solution is written as a series in terms of special functions that support a tridiagonal matrix representation for the angular and radial components of the wave operator. This solution is for all

A. E. Patrick

We investigate the properties of the Gibbs states and thermodynamic observables of the spherical model in a random field. We show that on the low-temperature critical line the magnetization of the model is not a self-averaging observable, but it self-averages conditionally. We also show that an arbitrarily weak homogeneous boundary field dominates over fluct

Mohamed Assad Abdel-Raouf

The emission of Auger electrons from the K-, L- and M-sheels of two configurations of copper atoms is investigated in detail within the frame work of the momentum average technique. Ab initio calculations for the bound state wavefunctions of the ionized atoms are performed using a Gaussian computer code. The continuum wavefunctions of the emitted electrons a

Mohamed Assad Abdel-Raouf

An elaborate least-squares variational technique is proposed for obtaining improved continuum wavefunctions of Auger electrons emitted from arbitrary systems the electronic structures of which are determined via one of the computer codes available. A computer program is developed on the basis of this technique for calculating the Auger transition rates using

G. Brodin, M. Marklund

We consider a low-temperature plasma within a newly developed MHD Fluid model. In addition to the standard terms, the electron spin, quantum particle dispersion and degeneracy effects are included. It turns out that the electron spin properties can give rise to Ferromagnetic behavior in certain regimes. If additional conditions are fulfilled, a homogenous ma

Nan Li, Sheng Chen

Suppose that $a_1(n),a_2(n),...,a_s(n),m(n)$ are integer-valued polynomials in $n$ with positive leading coefficients. This paper presents Popoviciu type formulas for the generalized restricted partition function $$p_{A(n)}(m(n)):=#\{(x_1,...,x_s)\in \mathbb{Z}^{s}: all x_j\geqslant 0, x_1a_1(n)+...+x_sa_s(n)=m(n) \}$$ when $s=2$ or 3. In either case, the fo

P. M. Gauthier, N. Tarkhanov

Approximation theorems, analogous to known results for linear elliptic equations, are obtained for solutions of the heat equation. Via the Cole-Hopf transformation, this gives rise to approximation theorems for a nonlinear parabolic equation, Burgers&#39; equation.

M. Eleftheriou, N. Lazarides, G. P. Tsironis

The existence and stability of discrete breathers (DBs) in one-dimensional and two-dimensional magnetic metamaterials (MMs), which consist of periodic arrangem ents (arrays) of split-ring resonators (SRRs), is investigated numerically. We consider different configurations of the SRR arrays, which are related to the relative orientation of the SRRs in the MM,

Craig D. Hodgson, Steven P. Kerckhoff

In this paper we develop a new theory of infinitesimal harmonic deformations for compact hyperbolic 3-manifolds with ``tubular boundary&#39;&#39;. In particular, this applies to complements of tubes of radius at least $R_0 = \arctanh(1/\sqrt{3}) \approx 0.65848$ around the singular set of hyperbolic cone manifolds, removing the previous restrictions on cone

Li-Gang Wang, Manzoor Ikram, M. Suhail Zubairy

We present a proposal to manipulate the Goos-Hanchen shift of a light beam via a coherent control field, which is injected into a cavity configuration containing the two-level atomic medium. It is found that the lateral shifts of the reflected and transmitted probe beams can be easily controlled by adjusting the intensity and detuning of the control field. U

K. Bekki, H. Yahagi, M. Nagashima, D. A. Forbes

Recent observations have reported that the Galactic globular clusters (GCs) with unusually extended horizontal-branch (EHB) morphologies show a significantly lower velocity dispersion compared with that of the entire Galactic GC system. We consider that the observed distinctive kinematics of GCs with EHB has valuable information on the formation epochs of GC