May 2006 arXiv papers — page 29

Abhas Mitra

By using virial theorem, Helmholtz and Kelvin showed that the contraction of a bound self-gravitating system must be accompanied by release of radiation energy irrespective of the details of the contraction process. This happens because the total Newtonian energy of the system E_N (and not just the Newtonian gravitational potential energy E_g^N) decreases fo

Tuerker Biyikoglu, Josef Leydold

We describe the structure of those graphs that have largest spectral radius in the class of all connected graphs with a given degree sequence. We show that in such a graph the degree sequence is non-increasing with respect to an ordering of the vertices induced by breadth-first search. For trees the resulting structure is uniquely determined up to isomorphis

Natali Zint, Ellen Baake, Frank den Hollander

A stochastic model for the activation of T-cells is analysed. T-cells are part of the immune system and recognize foreign antigens against a background of the body's own molecules. The model under consideration is a slight generalization of a model introduced by Van den Berg, Rand and Burroughs in 2001, and is capable of explaining how this recognition w

Joerg Behler, Bernard Delley, Karsten Reuter, Matthias Scheffler

Non-adiabatic effects play an important role in many chemical processes. In order to study the underlying non-adiabatic potential-energy surfaces (PESs), we present a locally-constrained density-functional theory approach, which enables us to confine electrons to sub-spaces of the Hilbert space, e.g. to selected atoms or groups of atoms. This allows to calcu

Demian H. J. Cho, Madhavan Varadarajan

Kucha{ř} showed that the quantum dynamics of (1 polarization) cylindrical wave solutions to vacuum general relativity is determined by that of a free axially-symmetric scalar field along arbitrary axially-symmetric foliations of a fixed flat 2+1 dimensional spacetime. We investigate if such a dynamics can be defined {\em unitarily} within the standard Fock s

Anbo Chen, Tianhong Yu, Renxin Xu

In this letter we propose a possible mechanism trying to alleviate the current difficulty in core-collapse supernovae by forming a strange quark star inside the collapsing core. Although the initial longtime cooling behavior of nascent strange stars is dominated by neutrino emissions, thermal emissions including photons and $e^\pm$ pair plasma do play a sign

Guangcun Lu, Gang Tian

The constructions of the virtual Euler (or moduli) cycles and their properties are explained and developed systematically in the general abstract settings.

Satoshi Fujimoto

We present the microscopic Fermi liquid theory for magnetic properties and transport phenomena in interacting electron systems without inversion symmetry both in the normal state and in the superconducting state. Our argument is mainly focused on the application to noncentrosymmetric heavy fermion superconductors. The transport coefficients for the anomalous

Kazuhiro Yamamoto, Bruce A. Bassett, Robert C. Nichol, Yasushi Suto

We discuss how the baryon acoustic oscillation (BAO) signatures in the galaxy power spectrum can distinguish between modified gravity and the cosmological constant as the source of cosmic acceleration. To this end we consider a model characterized by a parameter $n$, which corresponds to the Dvali-Gabadadze-Porrati (DGP) model if $n=2$ and reduces to the sta

Ken Kiers, Alejandro Szynkman, David London

Supersymmetric (SUSY) theories include many new parameters, some of which are CP-violating. Assuming that SUSY is found at a future high-energy collider, we examine the decay stop2 -> stop1 tau- tau+ with an eye to obtaining information about the new CP phases. We show that there are two CP-violating asymmetries which can be large in some regions of the SUSY

Marcelo Samuel Berman

We consider the energy of the Universe, from the pseudo-tensor point of view(Berman,1981). We find zero values, when the calculations are well-done.The doubts concerning this subject are clarified, with the novel idea that the justification for the calculation lies in the association of the equivalence principle, with the nature of co-motional observers, as

Joshua S. Friedman

For cofinite Kleinian groups (or equivalently, finite-volume three-dimensional hyperbolic orbifolds) with finite-dimensional unitary representations, we evaluate the regularized determinant of the Laplacian using W. Muller's regularization. We give an explicit formula relating the determinant to the Selberg zeta-function.

Ivone F. M. Albuquerque, Gustavo Burdman, Z. Chacko

In supersymmetric theories where the lightest supersymmetric particle is the gravitino the next to lightest supersymmetric particle is typically a long lived charged slepton. In this paper, following our earlier proposal, we perform a detailed study of the production of pairs of these particles induced by the interactions of high energy cosmic neutrinos with

Kiwoon Choi, Kwang Sik Jeong

We examine the effects of anomalous U(1)_A gauge symmetry on soft supersymmetry breaking terms while incorporating the stabilization of the modulus-axion multiplet responsible for the Green-Schwarz (GS) anomaly cancellation mechanism. In case of the KKLT stabilization of the GS modulus, soft terms are determined by the GS modulus mediation, the anomaly media

Mokshay Madiman, Andrew Barron

New families of Fisher information and entropy power inequalities for sums of independent random variables are presented. These inequalities relate the information in the sum of $n$ independent random variables to the information contained in sums over subsets of the random variables, for an arbitrary collection of subsets. As a consequence, a simple proof o

G. C. McLaughlin, R. Surman

Neutrinos from core collapse supernovae can be emitted from a rapidly accreting disk surrounding a black hole, instead of the canonical proto-neutron star. For Galactic events, detector count rates are considerable and in fact can be in the thousands for Super-Kamiokande. The rate of occurrence of these accreting disks in the Galaxy is predicted to be on the

M. Lucamarini, A. Cere', G. Di Giuseppe, S. Mancini

The security of a deterministic quantum scheme for communication, namely the LM05 [1], is studied in presence of a lossy channel under the assumption of imperfect generation and detection of single photons. It is shown that the scheme allows for a rate of distillable secure bits higher than that pertaining to BB84 [2]. We report on a first implementation of

Xiao Zheng, Fan Wang, GuanHua Chen

We prove that the electron density function of a real physical system can be uniquely determined by its values on any finite subsystem. This establishes the existence of a rigorous density-functional theory for any open electronic system. By introducing a new density functional for dissipative interactions between the reduced system and its environment, we s

Armin Uhlmann

Concurrence and further entanglement quantifyers can be computed explicitly for channels of rank two if representable by just two Kraus operators. Almost all details are available for the subclass of rank two 1-qubit-channels. There is a simple geometric picture beyond, explaining nicely the role of anti-linearity.

V. Karimipour

In a recent comment, it has been shown that in a quantum secret sharing protocol proposed in [S. Bagherinezhad, V. Karimipour, Phys. Rev. {\bf A}, 67, 044302, (2003)], one of the receivers can cheat by splitting the entanglement of the carrier and intercepting the secret, without being detected. In this reply we show that a simple modification of the protoco

D. N. Matsukevich, T. Chaneliere, S. D. Jenkins, S. -Y. Lan

A source of deterministic single photons is proposed and demonstrated by the application of a measurement-based feedback protocol to a heralded single photon source consisting of an ensemble of cold rubidium atoms. Our source is stationary and produces a photoelectric detection record with sub-Poissonian statistics.

Fumiaki Morikoshi

An information-theoretic temporal Bell inequality is formulated to contrast classical and quantum computations. Any classical algorithm satisfies the inequality, while quantum ones can violate it. Therefore, the violation of the inequality is an immediate consequence of the quantumness in the computation. Furthermore, this approach suggests a notion of tempo

Matthew Grace, Constantin Brif, Herschel Rabitz, Ian Walmsley

We present a formalism for encoding the logical basis of a qubit into subspaces of multiple physical levels. The need for this multilevel encoding arises naturally in situations where the speed of quantum operations exceeds the limits imposed by the addressability of individual energy levels of the qubit physical system. A basic feature of the multilevel enc

D. Kozakov, R. Brenke, S. Comeau, S. Vajda

The Fast Fourier Transform (FFT) correlation approach to protein-protein docking can evaluate the energies of billions of docked conformations on a grid if the energy is described in the form of a correlation function. Here, this restriction is removed, and the approach is efficiently used with pairwise interactions potentials that substantially improve the

Malik Rakhmanov

A special case of the relativistic Doppler effect, which occurs when light reflects from a moving mirror, is discussed. The classic formula for the Doppler shift is derived in a fully non-relativistic fashion using basic facts from geometry. The derivation does not involve Lorentz transformations, length contractions and time dilations, and therefore is conc

Beatriz Gato-Rivera

The Fermi Paradox is discussed in the light of the inflationary and brane world cosmologies. We conclude that some brane world cosmologies may be of relevance for the problem of civilizations spreading across our galaxy, strengthening the Fermi Paradox, but not the inflationary cosmologies, as has been proposed.

Xiaoqiang Wang, Qiang Du

In this paper, phase field models are developed for multi-component vesicle membranes with different lipid compositions and membranes with free boundary. These models are used to simulate the deformation of membranes under the elastic bending energy and the line tension energy with prescribed volume and surface area constraints. By comparing our numerical si

Hailu Luo, Wei Hu, Zhongzhou Ren, Weixing Shu

On the basis of angular spectrum representation, a formalism describing paraxial beams propagating through an isotropic left-handed material (LHM) slab is presented. The treatment allows us to introduce the ideas of beam focusing and phase compensation by LHM slab. Because of the negative refractive index of LHM slab, the inverse Gouy phase shift and the neg

Alexandros Alexakis, Charles R. Doering

Upper bounds on the bulk energy dissipation rate $ε$ and enstrophy dissipation rate $χ$ are derived for the statistical steady state of body forced two dimensional turbulence in a periodic domain. For a broad class of externally imposed body forces it is shown that $ε\le k_{f} U^3 Re^{-1/2}(C_1+C_2 Re^{-1})^{1/2}$ and $χ\le k_{f}^{3}U^3 (C_1+C_2 Re^{-1})$ wh

S. O'Brien, S. Osborne, K. Buckley, R. Fehse

A class of multiwavelength Fabry-Perot lasers is introduced where the spectrum is tailored through a non-periodic patterning of the cavity effective index. The cavity geometry is obtained using an inverse scattering approach and can be designed such that the spacing of discrete Fabry-Perot lasing modes is limited only by the bandwidth of the inverted gain me

J. Piekarewicz

The evolution of single-particle orbits along the N=28 isotonic chain is studied within the framework of a relativistic mean-field approximation. We focus on three topical aspects of the N=28 chain: (a) the emergence of a new magic number at Z=14; (b) the possible erosion of the N=28 shell; and (c) the weakening of the spin-orbit splitting among low-j neutro

Evan Finch

It has been over 30 years since the first suggestion that the true ground state of cold hadronic matter might be not nuclear matter but rather strange quark matter (SQM). Ever since, searches for stable SQM have been proceeding in various forms and have observed a handful of interesting events but have neither been able to find compelling evidence for stable

Matthew D. Finn, Jean-Luc Thiffeault

A fast method is presented for computing the topological entropy of braids on the torus. This work is motivated by the need to analyze large braids when studying two-dimensional flows via the braiding of a large number of particle trajectories. Our approach is a generalization of Moussafir's technique for braids on the sphere. Previous methods for comput

A. B. Tumpach

Mostow's Decomposition Theorem is a refinement of the polar decomposition. It states the following. Let G be a compact connected semi-simple Lie group with Lie algebra g. Given a subspace h of g such that [X, [X, Y]] belongs to h for all X and Y in h, the complexified group G^C with Lie algebra g + ig is homeomorphic to the product G .exp im. exp ih, whe

Grigori Rozenblum, Grigory Tashchiyan

The Landau Hamiltonian governing the behavior of a quantum particle in dimension 2 in a constant magnetic field is perturbed by a compactly supported magnetic field and a similar electric field. We describe how the spectral subspaces change and how the Landau levels split under this perturbation.

S. Molchanov, B. Vainberg

We consider an explicitly solvable model (formulated in the Riemannian geometry terms) for a stationary wave process in a specific thin domain with the Dirichlet boundary conditions on the boundary of the domain. The transition from the solutions of the scattering problem to the solutions of a problem on the limiting quantum graph is studied. We calculate th

Kazumasa Nomura, Paul Terwilliger

Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A : V \to V$ and $A^* : V \to V$ that satisfy (i) and (ii) below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is dia

Kazuo Habiro

We construct an invariant J_M of integral homology spheres M with values in a completion \hat{Z[q]} of the polynomial ring Z[q] such that the evaluation at each root of unity ζgives the the SU(2) Witten-Reshetikhin-Turaev invariant τ_ζ(M) of M at ζ. Thus J_M unifies all the SU(2) Witten-Reshetikhin-Turaev invariants of M. As a consequence, τ_ζ(M) is an algeb

Kazuo Habiro

We introduce an integral form U of the quantized enveloping algebra of sl_2. The algebra U is just large enough so that the quasi-R-matrix is contained in a completion of U\otimes U. We study several completions of the algebra U, and determine their centers. This study is motivated by a study of integrality properties of the quantum sl_2 invariants of links

Ignacio Guerra

Consider the problem \begin{eqnarray*} -Δu &=& v^{\frac 2{N-2}},\quad v>0\quad {in}\quad Ω, -Δv &=& u^{p},\:\:\:\quad u>0\quad {in}\quad Ω, u&=&v\:\:=\:\:0 \quad {on}\quad \partial Ω, \end{eqnarray*} where $Ω$ is a bounded convex domain in $\R^N,$ $N>2,$ with smooth boundary $\partial Ω.$ We study the asymptotic behaviour of the least energy solutions of thi

Zhenglu Jiang, Xiaoyong Fu, Hongjiong Tian

In this paper we give a simple proof of inequalities of integrals of functions which are the composition of nonnegative continous convex functions on a vector space ${\bf R}^m$ and vector-valued functions in a weakly compact subset of a Banach vector space generated by $m$ $L_μ^p$-spaces for $1\leq p<+\infty.$ Also, the same inequalities hold if these vector

Carlos Munuera, Fernando Torres

We characterize algebras admitting two well agreeing near weights $ρ$ and $σ$. We show that such an algebra $R$ is an integral domain whose quotient field $\mathbf K$ is an algebraic function field of one variable. It contains two places $p, Q\in {\mathbb P}(\mathbf K)$ such that $ρ$ and $σ$ are derived from the valuations associated to $P$ and $Q$. Furtherm

Tomas Everaert

We introduce a new notion of commutator which depends on a choice of subvariety in any variety of omega-groups. We prove that this notion encompasses Higgins&#39;s commutator, Froehlich&#39;s central extensions and the Peiffer commutator of precrossed modules.

J. M. Ancochea bermudez, R. Campoamor-Stursberg, M. Goze, L. Garcia Vergnolle

We present all real solvable algebraically rigid Lie algebras of dimension $n\leq 8$. The difference between the classification of complex and real rigid Lie algebras is analyzed.

Adam Skalski

In the first part of the paper the natural scheme for proving noncommutative individual ergodic theorems for multiple sequences is described and applied to obtain results on unrestricted convergence of multiaverages. In the second part convergence of ergodic averages induced by several maps satisfying specific recurrence relations, including so-called Multi

Victor Ivrii

I continue analysis of the Schrödinger operator with the strong degenerating magnetic field, started in \cite{IRO6}. Now I consider 4-dimensional case, assuming that magnetic field is generic degenerated and under certain conditions I derive spectral asymptotics with the principal part $\asymp h^{-4}$ and the remainder estimate $O(μ^{-1/2}h^{-3})$ where $μ\g

Domenico Fiorenza, Marco Manetti

We prove that, for every compact Kaehler manifold, the period map of its Kuranishi family is induced by a natural L-infinity morphism. This implies, by standard facts about L-infinity algebras, that the period map is a &#34;morphism of deformation theories&#34; and then commutes with all deformation theoretic constructions (e.g. obstructions).

Michael Baake, John A. G. Roberts

We present some of the group theoretic properties of reversing symmetry groups, and classify their structure in simple cases that occur frequently in several well-known groups of dynamical systems.

Karin Baur, Nolan R. Wallach

In this paper we give a classification of parabolic subalgebras of simple Lie algebras over $\mathbb{C}$ that satisfy two properties. The first property is Lynch&#39;s sufficient condition for the vanishing of certain Lie algebra cohomology spaces for generalized Whittaker modules associated with the parabolic subalgebra and the second is that the moment map

Feng Fu, Lianghuan Liu, Long Wang

A novel hierarchical model of complex network is proposed, and information propagation process taking place on top of the network is investigated. Our model is demonstrated to have small world property. We found that the frequency distribution of refractory elements number is bimodal and the location of initially chosen seed infection affects the spreading r

Philippe Rigollet, Alexandre Tsybakov

We study the problem of linear and convex aggregation of $M$ estimators of a density with respect to the mean squared risk. We provide procedures for linear and convex aggregation and we prove oracle inequalities for their risks. We also obtain lower bounds showing that these procedures are rate optimal in a minimax sense. As an example, we apply general res

Jorgen Ellegaard Andersen

Applying standard techniques from Toeplitz operator theory, we analyze the asymptotics of the Hilbert-Smith norms of the TQFT operators coming from isotopy classes of one dimensional oriented submanifolds on a closed oriented surface. We thereby obtain a Toeplitz operator interpretation and generalization of the asymptotic formula obtained recently by Marche

Jeffrey L. Caruso

This note attempts to make clear the relation between configurations of points in a space Y and those in its Cartesian product with the reals. We show that under certain conditions there is an equivalence between C(Y x R^n, X) and the n-th loop space of C(Y,S^n(X)).

Philippe Clement, Marta Garcia-Huidobro, Ignacio Guerra, Raul Manasevich

We give a new region of existence of solutions to the superhomogeneous Dirichlet problem $$ \quad \begin{array}{l} -Δ_{p} u= v^δ\quad v>0\quad {in}\quad B,\cr -Δ_{q} v = u^μ\quad u>0\quad {in}\quad B, \cr u=v=0 \quad {on}\quad \partial B, \end{array}\leqno{(S_R)} $$ where $B$ is the ball of radius $R>0$ centered at the origin in $\RR^N.$ Here $δ, μ>0$ and $

Mark Pavey

It is shown that the sum of class numbers of orders in totally complex quartic fields with no real quadratic subfield obeys an asymptotic law similar to the prime numbers, as the bound on the regulators tends to infinity. Here only orders which are maximal at a given set of primes containing an even number of elements are considered. The proof is accomplishe

Takeshi Ikeda

Let $LG_n$ denote the Lagrangian Grassmannian parametrizing maximal isotropic (Lagrangian) subspaces of a fixed symplectic vector space of dimension $2n.$ For each strict partition $λ=(λ_1,...,λ_k)$ with $λ_1\leq n$ there is a Schubert variety $X(λ).$ Let $T$ denote a maximal torus of the symplectic group acting on $LG_n.$ Consider the $T$-equivariant cohomo

Mohssin Zarouali-Darkaoui

We extend the comatrix coring to the case of a quasi-finite bicomodule. We also generalize some of its interesting properties. We study equivalences between categories of comodules over rather general corings. We particularize to the case of the adjoint pair of functors associated to a morphism of corings over different base rings. We apply our results to co

Claus Lehr, Michel Matignon

Let $R$ be a complete discrete valuation ring of mixed characteristic $(0,p)$ with field of fractions $K$ containing the $p$-th roots of unity. This paper is concerned with semi-stable models of $p$-cyclic covers of the projective line $C \la \PK$. We start by providing a new construction of a semi-stable model of $C$ in the case of an equidistant branch loc

James H. Ettle, Tim R. Morris

Recently, a canonical change of field variables was proposed that converts the Yang-Mills Lagrangian into an MHV-rules Lagrangian, i.e. one whose tree level Feynman diagram expansion generates CSW rules. We solve the relations defining the canonical transformation, to all orders of expansion in the new fields, yielding simple explicit holomorphic expressions

T. P. Singh

We do not know the symmetries underlying string theory. Furthermore, there must exist an inherently quantum, and spacetime independent, formulation of this theory. Independent of string theory, there should exist a description of quantum mechanics which does not refer to a classical spacetime manifold. We propose such a formulation of quantum mechanics, base

C. G. Honorato, J. J. Toscano

The production of pairs of doubly charged vector bileptons is studied at future $γγ$ colliders. The unpolarized cross--section for the $γγ\to Y^{--}Y^{++}$ subprocess is analytically calculated and convoluted to predict the number of events in the complete $e^+e^-\to γγ\to Y^{--}Y^{++}$ process. The gauge or non--gauge character of the vector bilepton $Y^{\p

Xiao-Bing Zhang, J. I. Kapusta

The electric/color neutral solution and the critical conditions for gapless formation are investigated in the $K^0$ condensed color-flavor locked matter. We point out that there exist no longer gapless modes for down-strange quark pairing while the gapless phenomenon for up-strange one is dominated in the $K^0$ condensed environment. In a model-independent w

A. Capella, E. G. Ferreiro

In the framework of a final state interaction model, we show that the so-called radial flow, i.e. the almost linear increase of the inverse slope $T$ with the mass of the produced particle, is already contained in the initial condition -- with a slope $<u_t^2>$ (the so-called strength of the average radial transverse flow) which is larger than the measured o

E. Arganda, M. J. Herrero

In this work the following lepton flavor violating $τ$ and $μ$ decays are studied: $τ^- \to μ^- μ^- μ^+$, $τ^- \to e^- e^- e^+$, $μ^- \to e^- e^- e^+$, $τ^- \to μ^- γ$, $τ^- \to e^- γ$ and $μ^- \to e^- γ$. We work in a constrained supersymmetric scenario with universal soft breaking terms and where the MSSM particle content is extended by the addition of thr

Jose Bernabeu, Catalina Espinoza

The goal for future neutrino facilities is the determination of the $[U_{e3}]$ mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam based on the recent discovery of nuclei that decay fast through electron capture is discussed.

Thorsten Renk, Jorg Ruppert

The NA60 experiment has studied low-mass muon pair production in In-In collisions at 158 AGeV with unprecedented precision. Thus, there is hope that the in-medium modifications of the vector meson spectral function can be constrained more thoroughly than from previous experiments. Towards this goal, we present a study comparing different models for the in-me

N. Akopov, L. Grigoryan, Z. Akopov

Nuclear attenuation of the two-hadron system is considered in the string model. The two-scale model and its improved version with two different choices of constituent formation time and sets of parameters obtained earlier for the single hadron attenuation, are used to describe available experimental data for the $z$-dependence of subleading hadron, whereas s

J. Haidenbauer, Ulf-G. Meißner, A. Sibirtsev

The near-threshold enhancement in the ppbar invariant mass spectrum from the B^+ -> K^+ ppbar decay reported recently by the BaBar Collaboration is studied within the Jülich NNbar model. We illustrate that the invariant mass dependence of the ppbar spectrum close to the threshold can be reproduced by the final state interactions. This explanation is in line

N. N. Achasov, A. V. Kiselev, G. N. Shestakov

The following topics are considered. 1) Confinement, chiral dynamics, and light scalar mesons. 2) Chiral shielding of the $σ(600)$. 3) The $ϕ$ meson radiative decays about nature of light scalar resonances. 4) The $J/ψ$ decays about nature of light scalar resonances. 5) The $a_0(980)\toγγ$ and $f_0(980)\toγγ$ decays about nature of light scalar resonances. 6

Andrea Banfi

We review the status of non-perturbative analyses of multi-jet event shape distributions and mean values, highlighting the physical insight on QCD dynamics they can provide.

Adrian Palcu

The mass splittings for the Majorana neutrinos in the exact solution of a particular 3-3-1 gauge model are computed here in detail. Since both $\sin^{2}θ_{13}\simeq0$ and the mass splittings ratio $r_Δ\simeq0.033$ are taken into account, the analytical calculations seem to predict an inverted mass hierarchy and a mixing matrix with a texture based on a very

X. -H. Guo, Bing-Lin Young

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on t

Tatsuo Kobayashi, Yuji Omura, Haruhiko Terao

We study realization of the democratic form of Yukawa matrices by infrared fixed points. We investigate renormalization-group flows of Yukawa couplings in models with a single Yukawa matrix for three families, and up and down-sector Yukawa matrices. It is found that each model has its certain pattern of renormalization-group flows of Yukawa matrices. We appl

Ph. Boucaud, J. P. Leroy, A. Le Yaouanc, A. Y. Lokhov

We study the infrared behaviour of the pure Yang-Mills correlators using relations that are well defined in the non-perturbative domain. These are the Slavnov-Taylor identity for three-gluon vertex and the Schwinger-Dyson equation for ghost propagator in the Landau gauge. We also use several inputs from lattice simulations. We show that lattice data are in s

A. J. Schwartz

We review results from searches for mixing and CP violation in the D0-D0bar system. No evidence for mixing or CP violation is found, and limits are set for the mixing parameters x, y, x&#39;, y&#39;, and several CP-violating parameters.

Stefan Hollands

We present an algorithm for constructing the Wilson operator product expansion (OPE) for perturbative interacting quantum field theory in general Lorentzian curved spacetimes, to arbitrary orders in perturbation theory. The remainder in this expansion is shown to go to zero at short distances in the sense of expectation values in arbitrary Hadamard states. W

S. Hansraj, S. D. Maharaj

We present solutions to the Einstein-Maxwell system of equations in spherically symmetric gravitational fields for static interior spacetimes with a specified form of the electric field intensity. The condition of pressure isotropy yields three category of solutions. The first category is expressible in terms of elementary functions and does not have an unch

S. D. Maharaj, S. Thirukkanesh

The condition for pressure isotropy, for spherically symmetric gravitational fields with charged and uncharged matter, is reduced to a recurrence equation with variable, rational coefficients. This difference equation is solved in general using mathematical induction leading to an exact solution to the Einstein field equations which extends the isotropic mod

Tanwi Bandyopadhyay, Subenoy Chakraborty

In the present work, gravitational collapse of an inhomogeneous spherical star model, consisting of inhomogeneous dust fluid (dark matter) in the background of dark energy is considered. The collapsing process is examined first separately for both dark matter and dark energy and then under the combined effect of dark matter and dark energy with or without in

T. P. Shestakova

We explore at phenomenological level a model of the Universe filled with various kinds of matter characterized by different equations of state. We show that introducing of each kind of matter is equivalent to a certain choice of a gauge condition, the gauge condition describing a medium with a given equation of state. The case of a particular interest is whe

Chad A. Cole, Stephen G. Wilson, Eric. K. Hall, Thomas R. Giallorenzi

This paper outlines a three-step procedure for determining the low bit error rate performance curve of a wide class of LDPC codes of moderate length. The traditional method to estimate code performance in the higher SNR region is to use a sum of the contributions of the most dominant error events to the probability of error. These dominant error events will

V. Arvind, Piyush P Kurur

We give a deterministic polynomial-time algorithm to check whether the Galois group $\Gal{f}$ of an input polynomial $f(X) \in \Q[X]$ is nilpotent: the running time is polynomial in $\size{f}$. Also, we generalize the Landau-Miller solvability test to an algorithm that tests if $\Gal{f}$ is in $Γ_d$: this algorithm runs in time polynomial in $\size{f}$ and $

V. M. Siddlenikov, R. N. Mohan, Moon Ho Lee

Abstrct: In this note, by considering fractionally linear functions over a finite field and consequently developing an abstract sequence, we study some of its properties.

S. Roch

In a recent breakthrough, [Bshouty et al., 2005] obtained the first passive-learning algorithm for DNFs under the uniform distribution. They showed that DNFs are learnable in the Random Walk and Noise Sensitivity models. We extend their results in several directions. We first show that thresholds of parities, a natural class encompassing DNFs, cannot be lear

João V. B. Soares, Jorge J. G. Leandro, Roberto M. Cesar, Herbert F. Jelinek

We present a method for automated segmentation of the vasculature in retinal images. The method produces segmentations by classifying each image pixel as vessel or non-vessel, based on the pixel&#39;s feature vector. Feature vectors are composed of the pixel&#39;s intensity and continuous two-dimensional Morlet wavelet transform responses taken at multiple s

Shai Ronen, Daniele C. E. Bortolotti, D. Blume, John L. Bohn

We consider a Bose-Einstein condensate of polar molecules in a harmonic trap, where the effective dipole may be tuned by an external field. We demonstrate that taking into account the dependence of the scattering length on the dipole moment is essential to reproducing the correct energies and for predicting the stability of the condensate. We do this by comp

Ashot Melikyan, Zlatko Tesanovic

In the mixed state of an extreme type-II d-wave superconductor and within a broad regime of weak magnetic fields H_c1 << H << H_c2, the low energy Bogoliubov-deGennes quasiparticles can be effectively described as Dirac fermions moving in the field of singular scalar and vector potentials. Although the effective linearized Hamiltonian operator formally does

G. A. Levin, P. N. Barnes, J. W. Kell, N. Amemiya

We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate metal in the grooves segregating the fil

Sow-Hsin Chen, Li Liu, Emiliano Fratini, Piero Baglioni

At low temperatures proteins exist in a glassy state, a state which has no conformational flexibility and shows no biological functions. In a hydrated protein, at and above 220 K, this flexibility is restored and the protein is able to sample more conformational sub-states, thus becomes biologically functional. This &#39;dynamical&#39; transition of protein

Maria Fyta, Pantelis C. Kelires

Using Monte Carlo simulations within the empirical potential approach, we examine the effect produced by the surface environment on the atomic level stresses in tetrahedral amorphous carbon. Both the distribution of stresses and the distributions of sp^2 and sp^3 atoms as a function of depth from the surface are highly inhomogeneous. They show the same close

Maria G. Fyta, Pantelis C. Kelires

Monte Carlo simulations, supplemented by ab initio calculations, shed light into the energetics and thermodynamic stability of nanostructured amorphous carbon. The interaction of the embedded nanocrystals with the host amorphous matrix is shown to determine in a large degree the stability and the relative energy differences among carbon phases. Diamonds are

K. A. Matveev, A Furusaki, L. I. Glazman

We study a system of one-dimensional electrons in the regime of strong repulsive interactions, where the spin exchange coupling J is small compared with the Fermi energy, and the conventional Tomonaga-Luttinger theory does not apply. We show that the tunneling density of states has a form of an asymmetric peak centered near the Fermi level. In the spin-incoh

L. C. Chapon, P. G. Radaelli, H. Zheng, J. F. Mitchell

YBaCo4O7 belongs to a new class of geometrically frustrated magnets like the pyrochlores, in which Co-spins occupy corners of tetrahedra. The structure can be viewed as an alternating stacking of Kagome and triangular layers. Exactly half of the triangular units of the Kagome plane are capped by Co ions to form columns running perpendicular to the Kagome she

J. Rech, C. Pepin, A. V. Chubukov

We consider the problem of fermions interacting with gapless long-wavelength collective bosonic modes. The theory describes, among other cases, a ferromagnetic quantum-critical point (QCP) and a QCP towards nematic ordering. We construct a controllable expansion at the QCP in two steps: we first create a new, non Fermi-liquid ``zero-order&#39;&#39; Eliashber

R. Casalini, U. Mohanty, C. M. Roland

The recently discovered scaling law for the relaxation times, tau=f(T,V^g), where T is temperature and V the specific volume, is derived by a revision of the entropy model of the glass transition dynamics originally proposed by Avramov [I. Avramov, J. Non-Cryst. Solids 262, 258 (2000).]. In this modification the entropy is calculated by an alternative route,

B. Rossi, P. Verrocchio, G. Viliani, G. Scarduelli

Vibrational properties of inclusion complexes with cyclodextrins are studied by means of Raman spectroscopy and numerical simulation. In particular, Raman spectra of the non-steroidal, anti-inflammatory drug indomethacin undergo notable changes in the energy range between 1600 and 1700 cm$^{-1}$ when inclusion complexes with cyclodextrins are formed. By usin

Thierry Lahaye, Gael Reinaudi, Zhaoying Wang, Antoine Couvert

We demonstrate transport and evaporative cooling of several atomic clouds in a chain of magnetic Ioffe-Pritchard traps moving at a low speed ($<1$~m/s). The trapping scheme relies on the use of a magnetic guide for transverse confinement and of magnets fixed on a conveyor belt for longitudinal trapping. This experiment introduces a new approach for paralleli

R. K. P. Zia, B. Schmittmann

We propose a general classification of nonequilibrium steady states in terms of their stationary probability distribution and the associated probability currents. The stationary probabilities can be represented graph-theoretically as directed labelled trees; closing a single loop in such a graph leads to a representation of probability currents. This classif

E. Szirmai, J. Sólyom

A two-leg ladder with $n$-component fermionic fields in the chains has been considered using an analytic renormalization group method. The fixed points and possible phases have been determined for generic filling as well as for a half-filled system and for the case when one of the subbands is half filled. A weak-coupling Luttinger-liquid phase and several st

Philippe Ghosez, Javier Junquera

The aim of this Chapter is to provide an account of recent advances in the first-principles modeling of ferroelectric oxide nanostructures. Starting from a microscopic description of ferroelectricity in bulk materials and considering then, successively, different kinds of nanostructures (films, multilayers, wires, and particles), we try to identify the main