October 2006 arXiv papers — page 7

Carsten Fortmann, Gerd Röpke, August Wierling

A basic concept to calculate physical features of non-ideal plasmas, such as optical properties, is the spectral function which is linked to the self-energy. We calculate the spectral function for a non-relativistic hydrogen plasma in $GW$-approximation. In order to go beyond $GW$ approximation, we include self-energy and vertex correction to the polarizatio

O. I. Kartavtsev, A. V. Malykh

The universal three-body dynamics in ultra-cold binary Fermi and Fermi-Bose mixtures is studied. Two identical fermions of the mass $m$ and a particle of the mass $m_1$ with the zero-range two-body interaction in the states of the total angular momentum L=1 are considered. Using the boundary condition model for the s-wave interaction of different particles,

Dirk Jacobmeier

The paper treats opinion dynamics of an unequal distribution as the initial opinion distribution. Simulated is the Deffuant model on a directed Barabasi-Albert network with discrete opinions and several subjects. Noticed is a focusing of the the resulting opinion distribution during the simulation towards the average value of the initial opinion distribution

Katja Klein

With an active silicon area of more than 200 squaremetres, the silicon strip tracker of the CMS experiment, one of the experiments currently under construction for the future Large Hadron Collider at CERN, will be by far the largest silicon tracker in the world. Efficient mass production and rigid quality control are crucial to finish the detector, comprisin

Gentaro Watanabe

In cores of supernovae and crusts of neutron stars, nuclei can adopt interesting shapes, such as rods or slabs, etc., which are referred to as nuclear "pasta." In recent years, we have studied the pasta phases focusing on their dynamical aspects with a quantum molecular dynamic (QMD) approach. In this article, we review these works. We also focus on

Eduardo Cuervo-Reyes, Ramis Movassagh

Geometrization of dynamics using (non)-affine parametization of arc length with time is investigated. The two archetypes of such parametrizations, the Eisenhart and the Jacobi metrics, are applied to a system of linear harmonic oscillators. Application of the Jacobi metric results in positive values of geometrical lyapunov exponent. The non-physical instabil

Raul E. Curto, Jasang Yoon

We study the class of hyponormal 2-variable weighted shifts with two consecutive equal weights in the weight sequence of one of the coordinate operators. We show that under natural assumptions on the coordinate operators, the presence of consecutive equal weights leads to horizontal or vertical flatness, in a way that resembles the situation for 1-variable w

Raul E. Curto, Sang Hoon Lee, Jasang Yoon

Let H_0 (resp. H_\infty denote the class of commuting pairs of subnormal operators on Hilbert space (resp. subnormal pairs), and for an integer k>=1 let H_k denote the class of k-hyponormal pairs in H_0. We study the hyponormality and subnormality of powers of pairs in H_k. We first show that if (T_1,T_2) is in H_1, then the pair (T_1^2,T_2) may fail to be i

Raul E. Curto, Sang Hoon Lee

We give the first example of a quartically hyponormal unilateral weighted shift which is not 3-hyponormal.

Raul E. Curto, Young Min Han

We find necessary and sufficient conditions for a Banach space operator T to satisfy the generalized Browder's theorem, and we obtain new necessary and sufficient conditions to guarantee that the spectral mapping theorem holds for the B-Weyl spectrum and for polynomials in T. We also prove that the spectral mapping theorem holds for the B-Browder spectru

Jing Zhang

We consider smooth threefolds $Y$ defined over $\Bbb{C}$ with $H^i(Y, Ω^j_Y)=0$ for all $j\geq 0$, $i>0$. Let $X$ be a smooth projective threefold containing $Y$ and $D$ be the boundary divisor with support $X-Y$. We are interested in the following question: What geometry information of $X$ can be obtained from the regular function information on $Y$? Suppos

Raul E. Curto, Lawrence A. Fialkow, H. Michael Moeller

For a degree 2n real d-dimensional multisequence β^(2n) to have a representing measure, it is necessary for the associated moment matrix M(n) to be positive semidefinite and for the algebraic variety V = V(β) associated to βto satisfy rank M(n) <= card V as well as the following consistency condition: if a polynomial p vanishes on V, then p(β) = 0. We prove

Jing Zhang

Let $Y$ be an algebraic manifold of dimension 3 with $H^i(Y, Ω^j_Y)=0$ for all $j\geq 0$, $i>0$ and $h^0(Y, {\mathcal{O}}_Y) > 1$. Let $X$ be a smooth completion of $Y$ such that the boundary $X-Y$ is the support of an effective divisor $D$ on $X$ with simple normal crossings. We prove that the $D$-dimension of $X$ cannot be 2, i.e., either any two nonconsta

Alexei Miasnikov, Enric Ventura, Pascal Weil

The aim of this paper is to unify the points of view of three recent and independent papers (Ventura 1997, Margolis, Sapir and Weil 2001 and Kapovich and Miasnikov 2002), where similar modern versions of a 1951 theorem of Takahasi were given. We develop a theory of algebraic extensions for free groups, highlighting the analogies and differences with respect

A. Vershik, P. Nikitin

We describe the central measures for the random walk on graded graphs. Using this description, we obtain the list of all finite traces on three infinite-dimensional algebras: on the Brauer algebra, on the partition algebra, and on the walled Brauer algebra. For the first two algebras, these lists coincide with the list of all finite traces of the infinite sy

S. S. Moskaliuk

Complex classical Cayley-Klein categories ${\bf A({\bj})}$, ${\bf B({\bj})}$, ${\bf C({\bj})}$ and ${\bf D({\bj})}$ are constructed by the method of categorical extension of the complex classical Cayley-Klein groups $SL(2n;{\bj};{\Bbb C}), SO(2n+1;{\bj};{\Bbb C}), Sp(2n;{\bj};{\Bbb C})$ and $SO(2n;{\bj};{\Bbb C})$, respectively. The explicit construction of

P. V. Golubtsov, S. S. Moskaliuk

This paper develops a category-theoretic approach to uncertainty, informativeness and decision-making problems. It is based on appropriate first order fuzzy logic in which not only logical connectives but also quantifiers have fuzzy interpretation. It is shown that all fundamental concepts of probability and statistics such as joint distribution, conditional

Dan Burghelea, Stefan Haller

In this paper we extend Witten-Helffer-Sjöstrand theory from selfadjoint Laplacians based on fiber wise Hermitian structures, to non-selfadjoint Laplacians based on fiber wise non-degenerate symmetric bilinear forms. As an application we verify, up to sign, the conjecture about the comparison of the Milnor-Turaev torsion with the complex valued analytic tors

Masaki Kashiwara, Kailash C. Misra, Masato Okado, Daisuke Yamada

A perfect crystal of any level is constructed for the Kirillov-Reshetikhin module of $U_q(D_4^{(3)})$ corresponding to the middle vertex of the Dynkin diagram. The actions of Kashiwara operators are given explicitly. It is also shown that this family of perfect crystals is coherent. A uniqueness problem solved in this paper can be applied to other quantum af

Daniel N. Blaschke, François Gieres, Olivier Piguet, Manfred Schweda

We show that the &#34;topological BF-type&#34; term introduced by Slavnov in order to cure the infrared divergences of gauge theories in noncommutative space can be characterized as the consequence of a new symmetry. This symmetry is a supersymmetry, generated by vector charges, of the same type as the one encountered in Chern-Simons or BF topological theori

Luigi Accardi, Andreas Boukas

Recently (cf. \cite{ABIDAQP06} and \cite{ABIJMCS06}) L. Accardi and A. Boukas proved that the generators of the second quantized Virasoro--Zamolodchikov--$w_{\infty}$ algebra can be expressed in terms of the Renormalized Higher Powers of White Noise and conjectured that this inclusion might in fact be an identity, in the sense that the converse is also true.

Levon Mardoyan, Armen Nersessian, Armen Yeranyan

We show that the inclusion of the monopole field in the three- and five-dimensional spherically symmetric quantum mechanical systems, supplied by the addition of the special centrifugal term, does not yield any change in the radial wavefunction and in the functional dependence of the energy spectra on quantum numbers. The only change in the spectrum is the l

P. V. Dong, H. N. Long, D. V. Soa

We show that, in frameworks of the economical 3-3-1 model, the suitable pattern of neutrino masses arises from the three quite different sources - the lepton-number conserving, the spontaneous lepton-number breaking and the explicit lepton-number violating, widely ranging over the mass scales including the GUT one: $u\sim O(1) \mathrm{GeV}$, $v\approx 246 \m

M. Haghighat, F. Loran

We address the problem of finding a system in which there would be measurable quantum gravitational effects. Following standard quantum-field methods, we have calculated the first-order radiative correction of graviton exchange on the binding energy of an electron with an ultra cold superfluid droplet of $^4$He with mass about the Planck mass. For two $^4$He

R. O. Kuzian, S. -L. Drechsler

The two-magnon problem for the frustrated XXZ spin-1/2 Heisenberg Hamiltonian and external magnetic fields exceeding the saturation field Bs is considered. We show that the problem can be exactly mapped onto an effective tight-binding impurity problem. It allows to obtain explicit exact expressions for the two-magnon Green&#39;s functions for arbitrary dimen

F. Mullally, Ted von Hippel, D. E. Winget

We present preliminary limits on the presence of planets around white dwarf stars using the IRAC photometer on the Spitzer space telescope. Planets emit strongly in the mid-infrared which allows their presence to be detected as an excess at these wavelengths. We place limits of $5 M_J$ for 8 stars assuming ages of $1 Gyr$, and $10 M_J$ for 23 stars.We descri

F. Combes, S. Garcia-Burillo, J. Braine, E. Schinnerer

We present the results of CO(1-0) emission mapping with the IRAM interferometer, at \sim 1 arcsec, resolution, of the z=0.223 ultra-luminous starburst IRAS 11582+3020. This galaxy was selected from an IRAM-30m survey of 30 galaxies at moderate redshift (z \sim 0.2-0.6) to explore galaxy evolution and in particular the star formation efficiency, in the redshi

J. Bouwman, W. A. Lawson, C. Dominik, E. D. Feigelson

The formation of planets is directly linked to the evolution of the circumstellar (CS) disk from which they are born. The dissipation timescales of CS disks are, therefore, of direct astrophysical importance in evaluating the time available for planet formation. We employ Spitzer Space Telescope spectra to complete the CS disk census for the late-type member

Ying-Qing Wu

Exceptional Dehn surgeries have been classified for 2-bridge knots and Montesinos knots of length at least 4. In this paper we classify all toroidal Dehn surgeries on Montesinos knots of length 3.

G. Gelmini, P. Gondolo, A. Soldatenko, C. E. Yaguna

We compute the neutralino direct detection rate in non-standard cosmological scenarios where neutralinos account for the dark matter of the Universe. Significant differences are found when such rates are compared with those predicted by the standard cosmological model. For bino-like neutralinos, the main feature is the presence of additional light ($m_χ\less

Vyacheslav Krushkal

A long-standing conjecture due to Michael Freedman asserts that the 4-dimensional topological surgery conjecture fails for non-abelian free groups, or equivalently that a family of canonical examples of links (the generalized Borromean rings) are not A-B slice. A stronger version of the conjecture, that the Borromean rings are not even weakly A-B slice, wher

Minhyea Lee, Y. Onose, Y. Tokura, N. P. Ong

Measurements of the Hall conductivity in MnSi can provide incisive tests of theories of the anomalous Hall (AH) effect, because both the mean-free-path and magnetoresistance (MR) are unusually large for a ferromagnet. The large MR provides an accurate way to separate the AH conductivity $σ_{xy}^A$ from the ordinary Hall conductivity $σ_{xy}^N$. Below the Cur

D. F. Urban, C. A. Stafford, Hermann Grabert

The Peierls instability in multi-channel metal nanowires is investigated. Hyperscaling relations are established for the finite-size-, temperature-, and wavevector-scaling of the electronic free energy. It is shown that the softening of surface modes at wavevector $q=2k_{F,ν}$ leads to critical fluctuations of the wire&#39;s radius at zero temperature, where

Jing Shu, Tim M. P. Tait, Carlos E. M. Wagner

We explore the possibility that the observed baryon asymmetry of the universe is the result of an earlier phase transition in which an extended gauge sector breaks down into the $SU(3)_C \times SU(2)_L \times U(1)_Y$ of the Standard Model. Our proto-typical example is the Topflavor model, in which there is a separate $SU(2)_1$ for the third generation from t

J. Bicak, V. Karas, T. Ledvinka

Stationary axisymmetric magnetic fields are expelled from outer horizons of black holes as they become extremal. Extreme black holes exhibit Meissner effect also within exact Einstein--Maxwell theory and in string theories in higher dimensions. Since maximally rotating black holes are expected to be astrophysically most important, the expulsion of the magnet

J. A. Ennis, L. Rudnick, W. T. Reach, J. D. Smith

We present Spitzer IRAC images, along with representative 5.27 to 38.5 micron IRS spectra of the Cassiopeia A supernova remnant. We find that various IRAC channels are each most sensitive to a different spectral and physical component. Channel 1 (3.6 micron) matches radio synchrotron images. Where Channel 1 is strong with respect to the other channels, the l

Nikodem J. Poplawski

We derive the expression for the snap parameter in f(R) gravity. We use the Palatini variational principle to obtain the field equations and regard the Einstein conformal frame as physical. We predict the present-day value of the snap parameter for the particular case f(R)=R-const/R, which is the simplest f(R) model explaining the current acceleration of the

Yoshimasa Hidaka, Masakiyo Kitazawa

We study the effect of a thermal quark mass, m_T, on the chiral phase transition and mesonic excitations in the light quark sector at finite temperature in a simple chirally-symmetric model. We show that while nonzero m_T lowers the chiral condensate, the chiral transition remains of second order. It is argued that the mesonic excitations have large decay ra

Martin Sahlén, Andrew R Liddle, David Parkinson

We update and extend our previous work reconstructing the potential of a quintessence field from current observational data. We extend the cosmological dataset to include new supernova data, plus information from the cosmic microwave background and from baryon acoustic oscillations. We extend the modelling by considering Padé approximant expansions as well a

Andrew N. Norris, I. D. Abrahams

Perturbation of a propagating crack with a straight edge is solved using the method of matched asymptotic expansions (MAE). This provides a simplified analysis in which the inner and outer solutions are governed by distinct mechanics. The inner solution contains the explicit perturbation and is governed by a quasi-static equation. The outer solution determin

Michael B. Green, Jorge G. Russo, Pierre Vanhove

This paper considers general features of the derivative expansion of Feynman diagram contributions to the four-graviton scattering amplitude in eleven-dimensional supergravity compactified on a two-torus. These are translated into statements about interactions of the form D^2k R^4 in type II superstring theories, assuming the standard M-theory/string theory

Mu-Chun Chen, K. T. Mahanthappa

In the minimal left-right symmetric model with spontaneous CP violation, there are only two intrinsic CP violating phases to account for all CP violation in both the quark and lepton sectors. In addition, the left-and right-handed Majorana mass terms for the neutrinos are proportional to each other due to the parity in the model. This is thus a very constrai

Alexandre Amblard, Asantha Cooray, Manoj Kaplinghat

B-modes of Cosmic Microwave Background (CMB) polarization can be created by a primordial gravitational wave background. If this background was created by Inflation, then the amplitude of the polarization signal is proportional the energy density of the universe during inflation. The primordial signal will be contaminated by polarized foregrounds including du

D. Greenbaum, S. Das, G. Schwiete, P. G. Silvestrov

We demonstrate theoretically the possibility to produce a pure spin current in graphene by filtering the charge from a spin-polarized electric current. To achieve this effect, which is based on the recently predicted property of specular Andreev reflection in graphene, we propose two possible device structures containing normal-superconductor (NS) junctions.

Nikodem J. Poplawski

We review the vacuum purely affine gravity with the nonsymmetric connection and metric. We also examine dynamical effects of the second Ricci tensor and covariant second-rank tensors constructed from the torsion tensor in the gravitational Lagrangian.

Gerhart Seidl

We consider a description of lattice gravity in six dimensions, where the two extra dimensions have been compactified on a warped hyperbolic disk of constant curvature. We analyze a fine-grained latticization of the hyperbolic disk in the context of an effective theory for massive gravitons. We find that in six-dimensional warped hyperbolic space, lattice gr

Miguel Sanchez

This paper has been withdrawn because the part concerning the definition of global hyperbolicity has already been included in an expanded and clearer way in gr-qc/0611138. The remainder will be also extended and posted.

Ehud Fuchs, Michael Kroyter

We find an analytical regularization for string field theory calculations. This regularization has a simple geometric meaning on the worldsheet, and is therefore universal as level truncation. However, our regularization has the added advantage of being analytical. We illustrate how to apply our regularization to both the discrete and continuous basis for th

Martin Hemberg, Mauricio Barahona

We present a Perfect Sampling algorithm that can be applied to the Master Equation of Gene Regulatory Networks (GRNs). The method recasts Gillespie&#39;s Stochastic Simulation Algorithm (SSA) in the light of Markov Chain Monte Carlo methods and combines it with the Dominated Coupling From The Past (DCFTP) algorithm to provide guaranteed sampling from the sta

Tao Liang

In this paper we examine numerically the properties, especially the scaling properties, of an isolated crescent singularity similar to that of a developable cone. The desired isolated crescent region is produced by applying six potential forces to an elastic sheet in a controlled way, for which no central pushing force is required. Two types of length scales

Chandrashekhar Khare, Michael Larsen, Gordan Savin

We prove that there are infinitely many finite simple groups of symplectic Lie type, of any specified characteristic and rank, which appear as Galois groups over the field of rational numbers. This generalizes a result of Wiese, which inspired this paper.

Eran Makover, Jeffrey McGowan

We investigate the size of the embedded regular tree rooted at a vertex in a $d$ regular random graph. We show that almost always, the radius of this tree will be ${1/2}\log n$, where $n$ is the number of vertices in the graph. And we give an asymptotic estimate for Gauss&#39; Hypergeometric Function.

Emilian Dudas, Chloe Papineau, Stefan Pokorski

We use the F-term dynamical supersymmetry breaking models with metastable vacua in order to uplift the vacuum energy in the KKLT moduli stabilization scenario. The main advantage compared to earlier proposals is the manifest supersymmetric treatment and the natural coexistence of a TeV gravitino mass with a zero cosmological constant. We argue that it is gen

Vaneet Aggarwal, A. Robert Calderbank

This paper describes a fundamental correspondence between Boolean functions and projection operators in Hilbert space. The correspondence is widely applicable, and it is used in this paper to provide a common mathematical framework for the design of both additive and non-additive quantum error correcting codes. The new framework leads to the construction of

C. Ortix, J. Lorenzana, M. Beccaria, C. Di Castro

We solve a model of phase separation among two competing phases frustrated by the long-range Coulomb interaction in two and three dimensions (2D/3D) taking into account finite compressibility effects. In the limit of strong frustration in 2D, we recover the results of R. Jamei, S. Kivelson, and B. Spivak, Phys. Rev. Lett. 94, 056805 (2005) and the system alw

Christine Bachoc, Frank Vallentin

We apply the semidefinite programming approach developed in arxiv:math.MG/0608426 to obtain new upper bounds for codes in spherical caps. We compute new upper bounds for the one-sided kissing number in several dimensions where we in particular get a new tight bound in dimension 8. Furthermore we show how to use the SDP framework to get analytic bounds.

David Angeli, Pierre-Alexandre Bliman

Results for estimating the convergence rate of non-stationary distributed consensus algorithms are provided, on the basis of qualitative (mainly topological) as well as basic quantitative information (lower-bounds on the matrix entries). The results appear to be tight in a number of instances and are illustrated through simple as well as more sophisticated e

M. Iovanov, J. Vercruysse

We study co-Frobenius and more generally Quasi-co-Frobenius corings over arbitrary baserings and over PF baserings in particular. We generalize some results about (Quasi-) co-Frobenius coalgebras to the case of non-commutative base rings and give several new characterisations for co-Frobenius and Quasi-co-Frobenius corings, some of them are new even in the c

Eric Emsellem

I very briefly discuss the ages and kinematics of spheroids as well as the black hole relations, via a few recent and illustrative studies, which include results on the downsizing, scaling laws, angular momentum and central massive objects.

T. Dereli, J. Gratus, R. W. Tucker

Electromagnetic properties of a simple polarisable medium may be parameterised in terms of a constitutive tensor whose properties can in principle be determined by experiments in non-inertial (accelerating) frames and in the presence of weak but variable gravitational fields. After establishing some geometric notation, discussion is given to basic concepts o

Dimitrie Culcer, Roland Winkler

We present a general unifying theory for spin polarization decay due to the interplay of spin precession and momentum scattering that is applicable to both spin-1/2 electrons and spin-3/2 holes. Our theory allows us to identify and characterize a wide range of qualitatively different regimes. For strong momentum scattering or slow spin precession we recover

Leon Brenig

Non-relativistic quantum mechanics for a free particle is shown to emerge from classical mechanics through an invariance principle under transformations that preserve the Heisenberg position-momentum inequality. These transformations are induced by isotropic space dilations. This invariance imposes a change in the laws of classical mechanics that exactly cor

Eric Emsellem

In this short report, I briefly review, illustrate and discuss various techniques (e.g., X ray halos, lensing, kinematics) used to derive mass (hence M/L) profiles of individual galaxies.

Pei Wang, You-Quan Li, Xuean Zhao

The intrinsic spin Hall conductivity in a two dimensional electron gas with Rashba spin-orbit coupling is evaluated by taking account of anisotropic coupling between magnetic impurities and itinerant electrons. In our calculation Kubo&#39;s linear response formalism is employed and the vertex correction is considered. In the semiclassical limit $μ\gg 1/τ$, a

Viv Kendon, Olivier Maloyer

Quantum versions of random walks on the line and the cycle show a quadratic improvement over classical random walks in their spreading rates and mixing times respectively. Non-unitary quantum walks can provide a useful optimisation of these properties, producing a more uniform distribution on the line, and faster mixing times on the cycle. We investigate the

A. P. Itin, S. Watanabe

We discuss dynamics of approximate adiabatic invariants in several nonlinear models being related to physics of Bose-Einstein condensates (BEC). We show that nonadiabatic dynamics in Feshbach resonance passage, nonlinear Landau-Zener (NLZ) tunnelling, and BEC tunnelling oscillations in a double-well can be considered within a unifying approach based on the t

Alberto Canonaco, Robert L. Karp

Given a smooth stacky Calabi-Yau hypersurface X in a weighted projective space, we consider the functor G which is the composition of the following two autoequivalences of D^b(X): the first one is induced by the spherical object O_X, while the second one is tensoring with O_X(1). The main result of the paper is that the composition of G with itself w times,

Eric Moreau

In this paper, connections between surface roughness and directed polymers in random medium are studied, when the surface is considered as a directed line undergoing stochastic oscillations. This is performed by studying the influence of a stochastic elastic forcing term $-κy+η(s)$, on a particle moving along a rough surface. Two models are proposed and anal

P. Tillman

The aim of this proceeding is to give a basic introduction to Deformation Quantization (DQ) to physicists. We compare DQ to canonical quantization and path integral methods. It is described how certain issues such as the roles of associativity, covariance, dynamics, and operator orderings are understood in the context of DQ. Convergence issues in DQ are ment

S. D. Huber, E. Altman, H. P. Büchler, G. Blatter

We study the excitation spectrum of strongly correlated lattice bosons for the Mott-insulating phase and for the superfluid phase close to localization. Within a Schwinger-boson mean-field approach we find two gapped modes in the Mott insulator and the combination of a sound mode (Goldstone) and a gapped (Higgs) mode in the superfluid. To make our findings c

Erik Taflin

We establish that solutions, to the most simple NLKG equations in 2 space dimensions with mass resonance, exhibits long range scattering phenomena. Modified wave operators and solutions are constructed for these equations. We also show that the modified wave operators can be chosen such that they linearize the non-linear representation of the Poincaré group

Frederic Pont, Claire Moutou, Michael Gillon, Andrzej Udalski

Transiting planets are essential to study the structure and evolution of extra-solar planets. For that purpose, it is important to measure precisely the radius of these planets. Here we report new high-accuracy photometry of the transits of OGLE-TR-10 and OGLE-TR-56 with VLT/FORS1. One transit of each object was covered in Bessel V and R filters, and treated

Jamila Douari

In this review, we introduce the electrified Dp-branes intersections in the low energy effective theory. We focus on D1-D3, D1-D5 and D0-D2 branes. We give the solutions configurations in the low energy effective theory in the absence and the presence of electric field by exciting one, two and three scalars in D3 system. The solutions from D3 point of view i

S. Pustelny, A. Wojciechowski, M. Kotyrba, K. Sycza

We demonstrate a magnetometric technique based on nonlinear magneto-optical rotation using amplitude modulated light. The magnetometers can be operated in either open-loop (typical nonlinear magneto-optical rotation with amplitude-modulated light) or closed-loop (self-oscillating) modes. The latter mode is particularly well suited for conditions where the ma

Tomas Hallgren

We consider Kaluza-Klein dark matter from deconstructed or latticized universal extra dimensions and study in this model the positron flux from Kaluza-Klein dark matter annihilation in the galactic halo.

Dominik Janzing, Pawel Wocjan

We describe two BQP-complete problems concerning properties of sparse graphs having a certain symmetry. The graphs are specified by efficiently computable functions which output the adjacent vertices for each vertex. Let i and j be two given vertices. The first problem consists in estimating the difference between the number of paths of length m from j to j

Luis A. Anchordoqui, Matthew M. Glenz, Leonard Parker

If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice-cap. We re-examine the prospects for observing such black holes with the IceCube neutrino-detection experiment. To this end, we first revise the black hole production rate by incorporating the

R. Alkofer, J. Greensite

We give a brief overview of the problem of quark confinement in hadronic physics, and outline a few of the suggested explanations of the confining force.

Heng-Zhong Fang, Jian-Yang Zhu

This paper investigates the particle radiation from Gibbons-Maeda black hole. Taking into account the self-gravitation of the particle, we calculate the tunnelling rate of the massless particle across the horizon, then we promote the work to the radiation of the charged particle. The calculations prove that the rate of tunnelling equals precisely the exponen

L. Lamata, J. Leon, D. Salgado, E. Solano

Using an inductive approach to classify multipartite entangled states under stochastic local operations and classical communication introduced recently by the authors [Phys. Rev. A 74, 052336 (2006)], we give the complete classification of four-qubit entangled pure states. Apart from the expected degenerate classes, we show that there exist eight inequivalen

S. Fiorucci, A. Benoit, L. Berge, J. Blumer

This paper presents our interpretation and understanding of the different backgrounds in the EDELWEISS-I data sets. We analyze in detail the several populations observed, which include gammas, alphas, neutrons, thermal sensor events and surface events, and try to combine all data sets to provide a coherent picture of the nature and localisation of the backgr

Mojtaba Mohammadi Najafabadi

The collider experiments at the Tevatron and the LHC provide us the possibility of probing the existence of a light charged Higgs boson. In this paper we study semi-leptonic decay of a polarized top quark via the charged Higgs boson ($t(\uparrow)\to H^{+}b \to l^{+}ν_{l}b$). It is shown that the asymmetry or spin correlation coefficient of the charged lepton

Naoki Yoshida, S. Peng Oh, Tetsu Kitayama, Lars Hernquist

(Abridged) We present the results of three-dimensional radiation-hydrodynamics simulations of the formation and evolution of early HII/HeIII regions around the first stars. Cooling (by H2 and HD) and recollapse of the gas in the relic HII region is also followed in a full cosmological context, until second-generation stars are formed. A large HII region with

Bhaskar Bagchi, Basudeb Datta

For integers $d \geq 2$ and $ε= 0$ or 1, let $S^{1, d - 1}(ε)$ denote the sphere product $S^{1} \times S^{d - 1}$ if $ε= 0$ and the twisted $S^{d - 1}$ bundle over $S^{1}$ if $ε= 1$. The main results of this paper are: (a) if $d \equiv ε$ (mod 2) then $S^{1, d - 1}(ε)$ has a unique minimal triangulation using $2d + 3$ vertices, and (b) if $d \equiv 1 - ε$ (m

Ionel Popescu

In this paper we discuss general tridiagonal matrix models which are natural extensions of the ones given by Dumitriu and Edelman. We prove here the convergence of the distribution of the eigenvalues and compute the limiting distributions in some particular cases. We also discuss the limit of fluctuations, which, in a general context, turn out to be Gaussian

M. Yoshida, K. Arai, R. Kaido, M. Takigawa

We report nuclear magnetic resonance studies on the beta-pyrochlore oxide superconductor KOs2O6. The nuclear relaxation at the K sites is entirely caused by fluctuations of electric field gradient, which we ascribe to highly anharmonic low frequency oscillation (rattling) of K ions. A phenomenological analysis shows a crossover from overdamped to underdamped

Bruno Kahn, R. Sujatha

Given a functor $T:C \to D$ carrying a class of morphisms $S\subset C$ into a class $S&#39;\subset D$, we give sufficient conditions in order that $T$ induces an equivalence on the localised categories. These conditions are in the spirit of Quillen&#39;s theorem A. We give some applications in algebaic and birational geometry.

Ionel Popescu

We give a short proof of the free analogue of the Talagrand inequality for the transportation cost to the semicircular which was originally proved by Biane and Voiculescu. The proof is based on a convexity argument and is in the spirit of the original Talagrand&#39;s proof. We also discuss the convergence, fluctuations and large deviations of the energy of t

Gary Gibbons, Kei-ichi Maeda, Yu-ichi Takamizu

We study the behaviour of five-dimensional fermions localized on branes, which we describe by domain walls, when two parallel branes collide in a five-dimensional Minkowski background spacetime. We find that most fermions are localized on both branes as a whole even after collision. However, how much fermions are localized on which brane depends sensitively

M. Grendar

Posterior distribution over a countable set M of continuous data-sampling distributions piles up at L-projection of the true distribution r on M, provided that the L-projection is unique. If there are several L-projections of r on M, then the posterior probability splits among them equally.

M. Hashimoto, T. Yoshida, K. Tanaka, A. Fujimori

We have performed a temperature-dependent angle-integrated photoemission study of lightly-doped to heavily-overdoped La$_{2-x}$Sr$_{x}$CuO$_4$ and oxygen-doped La$_2$CuO$_{4.10}$. We found that both the magnitude $Δ$* of the (small) pseudogap and the temperature \textit{T}* at which the pseudogap is opened increases with decreasing hole concentration, consis

L. Fedichkin, V. Privman

We outline different approaches to define and quantify decoherence. We argue that a measure based on a properly defined norm of deviation of the density matrix is appropriate for quantifying decoherence in quantum registers. For a semiconductor double quantum dot qubit, evaluation of this measure is reviewed. For a general class of decoherence processes, inc

James Colliander, Svetlana Roudenko

We observe a link between the window size of mass concentration and the rate of explosion of the Strichartz norm by revisiting Bourgain&#39;s mass concentration for the L^2-critical nonlinear Schrodinger equations.

Paul Fendley, Joel E. Moore, Cenke Xu

We study a constrained statistical-mechanical model in two dimensions that has three useful descriptions. They are 1) the Ising model on the honeycomb lattice, constrained to have three up spins and three down spins on every hexagon, 2) the three-color/fully-packed-loop model on the links of the honeycomb lattice, with loops around a single hexagon forbidden

A. Garmash

We report results of a Dalitz plot analysis of the three-body charmless B0=>K0pi+pi- decay. The analysis is performed with a data sample that contains 388 million BBbar pairs collected near the Y(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. Measurements of branching fractions for the quasi-two-body decays B0=>rho(770)0K0

Boju Jiang, Shicheng Wang, Hao Zheng

A quick proof of Bing's theorem indicated by the title is given. The proof also concludes Gumerov's result on covering degrees of solenoids.

Calin Chindris, Harm Derksen, Jerzy Weyman

We give counterexamples to Okounkov&#39;s log-concavity conjecture for Littlewood-Richardson coefficients.

D. Reznik, J. -P. Ismer, I. Eremin, L. Pintschovius

We present results of neutron scattering experiments on YBa2Cu3O6.95 (Tc=93K). Our results indicate that magnetic collective modes due to correlated local moments are present both above and below Tc in optimally doped YBCO. The magnon-like modes are robust and not overdamped by itinerant particle-hole excitations, which may point at a substantial static or s

Shamgar Gurevich, Ronny Hadani

In this paper we construct a geometric analogue of the Weil representation over a finite field. Our construction is principally invariant, not choosing any specific realization. This eliminates most of the unpleasant formulas that appear in the traditional (non-invariant) approaches, and puts in the forefront some delicate geometric phenomena which underlie

Erica Caden, Robert Gilmore

Resonances in the reflection probability amplitude r(E) can occur in energy ranges in which the reflection probability R(E)=|r(E)|^2 is 1. They occur as the phase phi(E) defined by r(E) = t*(E)/t(E) = 1e^{i 2phi(E)} undergoes a rapid change of pi radians. During this transition the phase angle exhibits a Lorentzian profile in that d(phi(E))/dE ~= 1/[(E-E_0)^