April 2006 arXiv papers — page 8

Azhar Iqbal

Research in quantum games has flourished during recent years. However, it seems that opinion remains divided about their true quantum character and content. For example, one argument says that quantum games are nothing but 'disguised' classical games and that to quantize a game is equivalent to replacing the original game by a different classical gam

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

We present a design for a quantum key distribution(QKD) system in a Sagnac loop configuration, employing a novel phase modulation scheme based on frequency shift, and demonstrate stable BB84 QKD operation with high interference visibility and low quantum bit error rate (QBER). The phase modulation is achieved by sending two light pulses with a fixed time del

Jose Gaite

The renormalization group is a tool that allows one to obtain a reduced description of systems with many degrees of freedom while preserving the relevant features. In the case of quantum systems, in particular, one-dimensional systems defined on a chain, an optimal formulation is given by White's "density matrix renormalization group". This formu

A. Fahmi

In this Paper, we investigate the security of Zhang, Li and Guo quantum key distribution via quantum encryption protocol [$\text{Phys. Rev. A} \textbf{64}, 24302 (2001)$] and show that it is not secure against some of Eve's attacks and with the probability one half she gets all of keys without being detected by the two parties. The main defect in this pr

Lin Chen, Yi-Xin Chen, Yu-Xue Mei

We give a further investigation of the range criterion and Low-to-High Rank Generating Mode (LHRGM) introduced in \cite{Chen}, which can be used for the classification of $2\times{M}\times{N}$ states under reversible local filtering operations. By using of these techniques, we entirely classify the family of $2\times4\times4$ states, which actually contains

Matthias Christandl

This thesis presents a study of the structure of bipartite quantum states. In the first part, the representation theory of the unitary and symmetric groups is used to analyse the spectra of quantum states. In particular, it is shown how to derive a one-to-one relation between the spectra of a bipartite quantum state and its reduced states, and the Kronecker

Caroline Kruszynska, Simon Anders, Wolfgang Dür, Hans J. Briegel

We study the preparation and distribution of high-fidelity multi-party entangled states via noisy channels and operations. In the particular case of GHZ and cluster states, we study different strategies using bipartite or multipartite purification protocols. The most efficient strategy depends on the target fidelity one wishes to achieve and on the quality o

Ronald de Wolf

The rigidity of a matrix measures how many of its entries need to be changed in order to reduce its rank to some value. Good lower bounds on the rigidity of an explicit matrix would imply good lower bounds for arithmetic circuits as well as for communication complexity. Here we reprove the best known bounds on the rigidity of Hadamard matrices, due to Kashin

Azhar Iqbal

Theory of quantum games is a new area of investigation that has gone through rapid development during the last few years. Initial motivation for playing games, in the quantum world, comes from the possibility of re-formulating quantum communication protocols, and algorithms, in terms of games between quantum and classical players. The possibility led to the

R. Wunschiers, R. Axelsson, P. Lindblad

Upon growth on dinitrogen, the filamentous cyanobacterium Nostoc PCC 7120 initiates metabolic and morphological changes. We analyzed the expression of 1249 genes from major metabolic categories under nitrogen fixing and non-nitrogen fixing growth. The expression data were correlated with potential target secondary structures, probe GC-content, predicted oper

Edmund R. Meyer, John L. Bohn, Michael P. Deskevich

This paper is a theoretical work in support of a newly proposed experiment (R. Stutz and E. Cornell, Bull. Am. Soc. Phys. 89, 76 2004) that promises greater sensitivity to measurements of the electron's electric dipole moment (EDM) based on the trapping of molecular ions. Such an experiment requires the choice of a suitable molecule that is both experime

L. M. Pismen

Motion of chemically driven droplets is analyzed by applying a solvability condition of perturbed hydrodynamic equations affected by the adsorbate concentration. Conditions for traveling bifurcation analogous to a similar transition in activator-inhibitor systems are obtained. It is shown that interaction of droplets leads to either scattering of mobile drop

Andreas Flache, Michael W. Macy

We relax a simplification of Axelrod's (1997) model of cultural dissemination that has not yet been studied, the assumption that all cultural states are nominal. We integrate metric states into the original model. Computational experiments demonstrate that metric states undermine cultural diversity, even without noise, by creating sufficient overlap betw

C. Milstene, G. Fisk, A. Para

Evolution of the Muon-ID package originally written by R. Markeloff at NIU. The original method used a helical swimmer to extrapolate the tracks from the Interaction Point and to collect hits in all sub-detectors: the electromagnetic and hadronic calorimeters and the muon detector. The package was modified to replace the swimmer by a stepper which does accou

Andre Sopczak

The alignment procedure of the Silicon Microstrip Tracker, SMT, and the Central Fiber Tracker, CFT, is described. Alignment uncertainties and resulting systematic errors in physics analyses are addressed.

Dietrich Stauffer, Muhammad Sahimi

Models that provide insight into how extreme positions regarding any social phenomenon may spread in a society or at the global scale are of great current interest. A realistic model must account for the fact that globalization and internet have given rise to scale-free networks of interactions between people. We propose a novel model which takes into accoun

A. S. de Castro, P. Alberto, R. Lisboa, M. Malheiro

We solve the generalized relativistic harmonic oscillator in 1+1 dimensions, i.e., including a linear pseudoscalar potential and quadratic scalar and vector potentials which have equal or opposite signs. We consider positive and negative quadratic potentials and discuss in detail their bound-state solutions for fermions and antifermions. The main features of

Avraham Gal

Following the prediction by Akaishi and Yamazaki of relatively narrow $\bar K$-nuclear states, deeply bound by over 100 MeV where the main decay channel $\bar K N \to πΣ$ is closed, several experimental signals in stopped $K^-$ reactions on light nuclei have been interpreted recently as due to such states. In this talk I review (i) the evidence from $K^-$-at

G. I. Gakh, E. Tomasi--Gustafsson, C. Adamuščín, S. Dubnička

Polarization effects in the reaction $e^++e^-\to \bar d+d$ have been investigated for the case of longitudinally polarized electron beam and arbitrary polarization of the produced deuteron, with the aim of a determination of the time-like complex deuteron electromagnetic form factors. General expressions of polarization observables are derived and numerical

G. Theocharis, P. G. Kevrekidis, D. J. Frantzeskakis, P. Schmelcher

Motivated by recent experimental studies of matter-waves and optical beams in double well potentials, we study the solutions of the nonlinear Schrödinger equation in such a context. Using a Galerkin-type approach, we obtain a detailed handle on the nonlinear solution branches of the problem, starting from the corresponding linear ones and predict the relevan

Steve Keen, Russell K. Standish

Neoclassical economics has two theories of competition between profit-maximizing firms (Marshallian and Cournot-Nash) that start from different premises about the degree of strategic interaction between firms, yet reach the same result, that market price falls as the number of firms in an industry increases. The Marshallian argument is strictly false. We int

J. Fernandez Nunez, W. Garcia Fuertes, A. M. Perelomov

In the previous paper math-ph/0507015 we have studied the characters and Clebsch-Gordan series for the exceptional Lie algebra E7 by relating them to the quantum trigonometric Calogero-Sutherland Hamiltonian with coupling constant K=1. Now we extend that approach to the case of general K.

Sergey Klishevich

In this paper we discuss constraints on two-dimensional quantum-mechanical systems living in domains with boundaries. The constrains result from the requirement of hermicity of corresponding Hamiltonians. We construct new two-dimensional families of formally exactly solvable systems and applying such constraints show that in real the systems are quasi-exactl

Ricardo M Bentin

We will pursue a way of building up an algebraic structure that involves, in a mathematical abstract way, the well known Grassmann variables. The problem arises when we tried to understand the grassmannian polynomial expansion on the scope of ring theory. The formalization of this kind of variables and its properties will help us to have a better idea of som

Shu-Cheng Chang, Peng Lu

In this note under a crucial technical assumption we derive a differential equality of the Yamabe constant $\mathcal{Y} (g (t))$ where $g (t)$ is a solution of the Ricci flow on a closed manifold.

Alan Hopenwasser

The Cuntz algebra O_n is presented as a partial crossed product in which an amenable group partially acts on an abelian C*-algebra. The partial action is related to the Cuntz groupoid for O_n and connections are made with non-self-adjoint subalgebras of O_n, particularly the Volterra nest subalgebra. These ideas are also extended to the M_k(O_n) context.

John Bolton, Luc Vrancken

Recently Oprea gave an improved version of Chen's inequality for Lagrangian submanifolds of $\mathbb CP^n(4)$. For minimal submanifolds this inequality coincides with the original previously proved version. We consider here those non minimal 3-dimensional Lagrangian submanifolds in $\mathbb CP^3 (4)$ attaining at all points equality in the improved Chen

Samy Skander Bahoura

We prove an a priori estimate of type sup*inf on Riemannian manifold of dimension 3 (not necessarily compact).

Trueman MacHenry, Kieh Wong

Linear recursions of degree $k$ are determined by evaluating the sequence of Generalized Fibonacci Polynomials, $\{F_{k,n}(t_1,...,t_k)\}$ (isobaric reflects of the complete symmetric polynomials) at the integer vectors $(t_1,...,t_k)$. If $F_{k,n}(t_1,...,t_k) = f_n$, then $$f_n - \sum_{j=1}^k t_j f_{n-j} = 0,$$ and $\{f_n\}$ is a linear recursion of degree

Oscar Moreno, Dorothy Bollman, Maria A. Avino-Diaz

We establish a connection between finite fields and finite dynamical systems. We show how this connection can be used to shed light on some problems in finite dynamical systems and in particular, in linear systems.

Julien Marche, Majid Narimannejad

For each oriented surface $Σ$ of genus $g$ we study a limit of quantum representations of the mapping class group arising in TQFT derived from the Kauffman bracket. We determine that these representations converge in the Fell topology to the representation of the mapping class group on $\boH(Σ)$, the space of regular functions on the $SL(2,\C)$ representatio

Gregory Cresp

A finite linear space is a finite set of points and lines, where any two points lie on a unique line. Well known examples include projective planes. This project focuses on linear spaces which admit certain types of symmetries. Symmetries of the space which preserve the line structure are called automorphisms. A group of these is called an automorphism group

V. Shcherbakov

We consider a finite sequence of random points in a finite domain of a finite-dimensional Euclidean space. The points are sequentially allocated in the domain according to a model of cooperative sequential adsorption. The main peculiarity of the model is that the probability distribution of a point depends on previously allocated points. We assume that the d

Giovanni Peccati, Murad S. Taqqu

We prove sufficient conditions, ensuring that a sequence of multiple Wiener-Itô integrals (with respect to a general Gaussian process) converges stably to a mixture of normal distributions. Our key tool is an asymptotic decomposition of contraction kernels, realized by means of increasing families of projection operators. We also use an infinite-dimensional

Samy Skander Bahoura

We give some a priori estimates of type sup*inf for Yamabe and prescribed scalar curvature type equations on Riemannian manifolds of dimension >2. The product sup*inf is caracteristic of those equations, like the usual Harnack inequalities for non negative harmonic functions. First, we have a lower bound for sup*inf for some classes of PDE on compact manifol

Michael Puschnigg

It is shown that Connes' character formula for unbounded, theta-summable Fredholm modules represents the abstract Chern-character in K-homology. As an application, the character of a particular Fredholm module over the reduced group C*-algebra of a discrete group is calculated, which leads to a partial solution of a problem posed by A.Connes.

Giovanni Peccati, Murad S. Taqqu

Consider generalized adapted stochastic integrals with respect to independently scattered random measures with second moments. We use a decoupling technique, known as the "principle of conditioning", to study their stable convergence towards mixtures of infinitely divisible distributions. Our results apply, in particular, to multiple integrals with r

G. S. Asanov

In the previous work, the notion of the Finsleroid--Finsler space have been formulated and the necessary and sufficient conditions for the space to be of the Landsberg type have been found. In the present paper, starting with particular spray coefficients, we demonstrate how the Landsberg condition can explicitly appear in case of the Finsleroid--type metric

Frédéric Chapoton

We compute the characteristic polynomials of the posets of hypertrees. We show that the generating series of the polynomials can be expressed using cyclic hypertrees. We also propose a conjecture on the action of the symmetric groups on the homology of these posets. On the other hand, we show that Vallette's poset of pointed partitions is homotopy equiva

Nils Bruin, Michael Stoll

We consider all genus 2 curves over Q given by an equation y^2 = f(x) with f a squarefree polynomial of degree 5 or 6, with integral coefficients of absolute value at most 3. For each of these roughly 200000 isomorphism classes of curves, we decide if there is a rational point on the curve or not, by a combination of techniques. For a small number of curves,

Julien Berestycki

In this paper we define and study self-similar ranked fragmentations. We first show that any ranked fragmentation is the image of some partition-valued fragmentation, and that there is in fact a one-to-one correspondence between the laws of these two types of fragmentations. We then give an explicit construction of homogeneous ranked fragmentations in terms

Jiun-Cheng Chen

We generalize the well-known numerical criterion for projective spaces by Cho, Miyaoka and Shepherd-Barron to varieties with at worst quotient singularities. Let $X$ be a normal projective variety of dimension $n \geq 3$ with at most quotient singularities. Our result asserts that if $C \cdot (-K_X) \geq n+1$ for every curve $C \subset X$, then $X \cong \PP^

M. D. Gould, T. Lekatsas

We introduce quasi-Hopf $*$-algebras i.e. quasi-Hopf algebras equipped with a conjugation (star) operation. The definition of quasi-Hopf $*$-algebras proposed ensures that the class of quasi-Hopf $*$-algebras is closed under twisting and additionally, that any Hopf $*$-algebra becomes a quasi-Hopf $*$-algebra via twisting. The basic properties of these algeb

Raphael Ponge

This paper is an extended version of math.OA/0601528 where we point out and remedy a gap in the proof by P. Julg and G. Kasparov of the Baum-Connes conjecture for discrete subgroups of SU(n,1). In particular, here we explain in details why the non-microlocality of the Heisenberg calculus prevents us from implementing into this framework the classical approac

Raphael Ponge

In this note we point out and fill a gap in the proof by Julg-Kasparov of the Baum-Connes conjecture with coefficients for discrete subgroups of $\op{SU}(n,1)$. The issue at stake is the proof that the complex powers of the contact Laplacian are element of the Heisenberg calculus. In particular, we explain why we cannot implement into the setting of the Heis

Hun Hee Lee

We investigate some extremal cases of exactness constant and completely bounded projection constant. More precisely, for an $n$-dimensional operator space $E$ we prove that $λ_{cb}(E) = \sqrt{n}$ if and only if $ex(E) = \sqrt{n}$, which is equivalent to $λ_{cb}(E) < \sqrt{n}$ if and only if $ex(E) < \sqrt{n}$.

B. Toen

The purpose of this work is to define a derived Hall algebra $\mathcal{DH}(T)$, associated to any dg-category $T$ (under some finiteness conditions). Our main theorem states that $\mathcal{DH}(T)$ is associative and unital. It is shown that $\mathcal{DH}(T)$ contains the usual Hall algebra $\mathcal{H}(T)$ when $T$ is an abelian category. We will also prove

Michael Megrelishvili, Lutz Schroeder

We generalize Exel&#39;s notion of partial group action to monoids. For partial monoid actions that can be defined by means of suitably well-behaved systems of generators and relations, we employ classical rewriting theory in order to describe the universal induced global action on an extended set. This universal action can be lifted to the setting of topolo

B. Toen

This is an expended and revised version of the preprint &#34;Schematization of homotopy types&#34;. The purpose of this work is to introduce a notion of \emph{affine stacks}, which is a homotopy version of the notion of affine schemes, and to give several applications in the context of algebraic topology and algebraic geometry. As a first application we show

Leszek Hadasz, Zbigniew Jaskolski

Few years ago Zamolodchikov and Zamolodchikov proposed an expression for the 4-point classical Liouville action in terms of the 3-point actions and the classical conformal block. In this paper we develop a method of calculating the uniformizing map and the uniformizing group from the classical Liouville action on n-punctured sphere and discuss the consequenc

Laurent Freidel, Robert G. Leigh, Djordje Minic

We discuss an analytic approach towards the solution of pure Yang-Mills theory in 3+1 dimensional spacetime. The approach is based on the use of local gauge invariant variables in the Schrödinger representation and the large $N$, planar limit. In particular, within this approach we point out unexpected parallels between pure Yang-Mills theory in 2+1 and 3+1

C. Bogdanos, A. Dimitriadis, K. Tamvakis

We consider the problem of a scalar field, non-minimally coupled to gravity through a $-ξϕ^{2}R$ term, in the presence of a Brane. Exact solutions, for a wide range of values of the coupling parameter $ξ$, for both $ϕ$-dependent and $ϕ$-independent Brane tension, are derived and their behaviour is studied. In the case of a Randall-Sundrum geometry, a class o

L. Freidel, K. Noui, P. Roche

It is known that the Fourier transformation of the square of (6j) symbols has a simple expression in the case of su(2) and U_q(su(2)) when q is a root of unit. The aim of the present work is to unravel the algebraic structure behind these identities. We show that the double crossproduct construction H_1\bowtie H_2 of two Hopf algebras and the bicrossproduct

Kirill Saraikin

We consider a generating function for the number of conformal blocks in rational conformal field theories with an even central charge c on a genus g Riemann surface. It defines an entropy functional on the moduli space of conformal field theories and is captured by the gauged WZW model whose target space is an abelian variety. We study a special coupling of

Natalia Shuhmaher, Robert Brandenberger

We propose a new way of obtaining slow-roll inflation in the context of higher dimensional models motivated by string and M theory. In our model, all extra spatial dimensions are orbifolded. The initial conditions are taken to be a hot dense bulk brane gas which drives an initial phase of isotropic bulk expansion. This phase ends when a weak potential betwee

Alex Gomes Dias

The possibility of generating neutrino mass through see-saw mechanism involving U(1) chiral Peccei-Quinn and scale symmetries breakdown is discussed. We consider a generic scale invariant model which has three Majorana fermions and a complex scalar singlet, which might be the one responsible for an invisible axion, and we perform a summation of all leading l

Giacomo Cacciapaglia, Csaba Csaki, Christophe Grojean, John Terning

We consider extra dimensional field theory descriptions of backgrounds with N different throats where one of the extra dimensions in each throat is much larger than the others. Such backgrounds can be described by field theory on N 5D warped spaces which intersect on a ultraviolet (UV) brane. Given a field that propagates in all N throats there are N boundar

Asmaa Abada, Gregory Moreau

We consider the Next to Minimal Supersymmetric Standard Model (NMSSM) which provides a natural solution to the so-called mu problem by introducing a new gauge-singlet superfield S. We realize that a new mechanism of neutrino mass suppression, based on the R-parity violating bilinear terms mu_i L_i H_u mixing neutrinos and higgsinos, arises within the NMSSM,

Rohini M. Godbole, Agnes Grau, Rohit Hegde, Giulia Pancheri

In this note, we summarize and compare various model predictions for $pp$ total cross-section $σ_{\rm tot}^{pp}$, giving an estimate of the range of predictions for the total cross-section, $σ_{\rm tot}^{pp}$ expected at the LHC. We concentrate on the results for $σ_{\tot}^{pp}$ obtained in a particular QCD based model of the energy dependence of the total c

A. Yu. Smirnov

Comparison of properties of quark and leptons as well as understanding their similarities and differences is one of the milestones on the way to underlying physics. Several observations, if not accidental, can strongly affect the implications: (i) nearly tri-bimaximal character of lepton mixing, (ii) special neutrino symmetries, (iii) the QLC-relations. We c

M. R. Pennington

There has long been speculation about the nature of the $σ$-resonance. For three decades Jaffe has argued for a tetraquark composition, while others have claimed it is largely a glueball. A key pointer to its nature is its coupling to two photons. Consequently, there have been recent proposals to observe this important scalar hiding in $γγ\toπ^0π^0$. We show

R. M. Godbole, A. Grau, G. Pancheri, Y. N. Srivastava

We discuss a model for total hadronic and photonic cross-sections which includes hard parton-parton scattering to drive the rise and soft gluon resummation to tame it. Unitarity is ensured by embedding the cross-section in the eikonal formalism. Predictions for LHC and ILC are presented.

Bruno G. Taketani, Eduardo S. Fraga

We consider an approximation procedure to evaluate the finite-temperature one-loop fermionic density in the presence of a chiral background field which systematically incorporates effects from inhomogeneities in the chiral field through a derivative expansion. Modifications in the effective potential and their consequences for the bubble nucleation process a

Victor Varela

We build extended sources for the Reissner-Nordström metric. Our models describe a neutral perfect fluid core bounded by a charged thin shell, and feature everywhere positive rest mass density and everywhere non-negative active gravitational mass, as well as classical electron radius and electromagnetic total mass. We contrast our results with previously dis

Vita Hinze-Hoare

Under consideration are the general set of Human computer Interaction (HCI) and Educational principles from prominent authors in the field and the construction of a system for evaluating Virtual Learning Environments (VLEs) with respect to the application of these HCI and Educational Principles. A frequency analysis of principles is used to obtain the most s

Vita Hinze-Hoare

The general set of HCI and Educational principles are considered and a classification system constructed. A frequency analysis of principles is used to obtain the most significant set. Metrics are devised to provide objective measures of these principles and a consistent testing regime devised. These principles are used to analyse Blackboard and Moodle.

Alin Bostan, Frédéric Chyzak, François Ollivier, Bruno Salvy

We propose new algorithms for the computation of the first N terms of a vector (resp. a basis) of power series solutions of a linear system of differential equations at an ordinary point, using a number of arithmetic operations which is quasi-linear with respect to N. Similar results are also given in the non-linear case. This extends previous results obtain

Lawrence Ong, Mehul Motani

We investigate the achievable rate of data transmission from sources to sinks through a multiple-relay network. We study achievable rates for omniscient coding, in which all nodes are considered in the coding design at each node. We find that, when maximizing the achievable rate, not all nodes need to ``cooperate&#39;&#39; with all other nodes in terms of co

Lawrence Ong, Mehul Motani

In this paper, we investigate achievable rates on the multiple access channel with feedback and correlated sources (MACFCS). The motivation for studying the MACFCS stems from the fact that in a sensor network, sensors collect and transmit correlated data to a common sink. We derive two achievable rate regions for the three-node MACFCS.

Tracey Ho

We consider the problem of network coding across multiple unicasts. We give, for wired and wireless networks, efficient polynomial time algorithms for finding optimal network codes within the class of network codes restricted to XOR coding between pairs of flows.

M. S. Kim, Y. Nakai, H. Tou, M. Sera

The thermopower, S, of CexR1-xB6 (R=La, Pr, Nd) was investigated. S with a positive sign shows a typical behavior observed in the Ce Kondo system, an increase with decreasing temperature at high temperatures and a maximum at low temperatures. The S values of all the systems at high temperatures are roughly linearly dependent on the Ce concentration, indicati

Massimo Mannarelli, Giuseppe Nardulli, Marco Ruggieri

The phase diagram of a non-relativistic fermionic system with imbalanced state populations interacting via a short-range S-wave attractive interaction is analyzed in the mean field approximation. We determine the energetically favored state for different values of the mismatch between the two Fermi spheres in the weak and strong coupling regime considering b

N. P. Stern, R. C. Myers, M. Poggio, A. C. Gossard

Recent measurements of coherent electron spin dynamics reveal an antiferromagnetic s-d exchange coupling between conduction band electrons and electrons localized on Mn{2+} impurities in GaMnAs quantum wells. Here we discuss systematic measurements of the s-d exchange interaction in GaMnAs/AlGaAs quantum wells with different confinement potentials using time

Alvaro Corral

A review of the statistical properties of earthquakes is provided, centered mainly in the work of the author (apologies for that). We explain the scaling law for the recurrence-time distributions, its universal character for stationary seismicity and for Omori sequences, the counterintuitive phenomenon of decreasing hazard with time and the increasing of the

E. V. Vakarin, J. P. Badiali

Statistical properties of coupled dynamic-stochastic systems are studied within a combination of the maximum information principle and the superstatistical approach. The conditions at which the Shannon entropy functional leads to a power-law statistics are investigated. It is demonstrated that, from a quite general point of view, the power-law dependencies m

Kwai-Kong Ng, T. K. Lee

Using quantum Monte Carlo method, we study, under external magnetic fields, the ground state phase diagram of the two-dimensional spin $S$=1/2 dimer model with an anisotropic intra-plane antiferromagnetic coupling. With the anisotropy $4 \gtrsim Δ\gtrsim 3$, a supersolid phase characterized by a non-uniform bose condensate density that breaks translational s

Einat Klein, Noam Gross, Evi Kopelowitz, Michael Rosenbluh

We study the mutual coupling of chaotic lasers and observe both experimentally and in numeric simulations, that there exists a regime of parameters for which two mutually coupled chaotic lasers establish isochronal synchronization, while a third laser coupled unidirectionally to one of the pair, does not synchronize. We then propose a cryptographic scheme, b

A. J. Archer

Starting from Newton&#39;s equations of motion, we derive a dynamical density functional theory (DDFT) applicable to atomic liquids. The theory has the feature that it requires as input the Helmholtz free energy functional from equilibrium density functional theory. This means that, given a reliable equilibrium free energy functional, the correct equilibrium

K. N. Anuradha, S. S. Rao, S. V. Bhat

Nanowires of Pr_0.57 Ca_0.41 Ba_0.02 MnO_3 (PCBM) (diameter ~ 80-90 nm and length ~ 3.5 mm) were synthesized by a low reaction temperature hydrothermal method. Single-phase nature of the sample was confirmed by XRD experiments. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the morphology and microstru

V. V. Aristov, A. V. Nikulov

In order to have a chance to make a real quantum computer it is important to find the entanglement phenomenon on mesoscopic level since technology can not be able in the visible future to work on atomic level. It is known that the entanglement (the EPR correlation) violates the principle of local realism. Existence of EPR correlation on a level higher than a

Guoxiang Huang, L. Deng, Jiaren Yan, Bambi Hu

We present rigorous results on the diagonalization of Bogoliubov Hamilto- nian for a soliton condensate. Using the complete and orthonomalized set of eigenfunction for the Bogoliubov de Gennes equations, we calculate ex- actly the quantum depletion of the condensate and show that two degenerate zero-modes, which originate from a U(1) guage- and a translation

J. M. Deutsch, A. Berger

In many magnetic materials, spin dynamics at short times are dominated by precessional motion as damping is relatively small. In the limit of no damping and no thermal noise, we show that for a large enough initial instability, an avalanche can transition to an ergodic phase where the state is equivalent to one at finite temperature, often above that for fer

S. de Palo, M. Botti, S. Moroni, Gaetano Senatore

We reply to the comment by Ying Zhang and S. Das Sarma on our PRL 94, 226405 (2005).

Felix Höfling, Thomas Franosch, Erwin Frey

The localization transition and the critical properties of the Lorentz model in three dimensions are investigated by computer simulations. We give a coherent and quantitative explanation of the dynamics in terms of continuum percolation theory, an excellent matching of both the critical density and exponents is obtained. Upon exploiting a dynamic scaling Ans

B. E. Dobrescu, V. L. Pokrovsky

We present a consistent nonequilibrium theory for the production of molecular dimers from a two-component quantum-degenerate fermion atomic gas, via a linear downward sweep of the magnetic field across a Feshbach resonance. This problem raises interest because it is presently unclear as to why deviations from the universal Landau-Zener formula for the transi

I. Kakeya, M. Iwase, T. Yamazaki, T. Yamamoto

Dynamical nature of the Josephson vortex (JV) system in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ (Bi2212) has been investigated in the presence of the c-axis current with magnetic field alignments very close to the $ab$-plane. As a function of magnetic fields, the c-axis JV flux flow resistance oscillates periodically in accordance with the proposed JV triangular struc

S. C. Wolff, S. E. Strom, D. Dror, L. Lanz

We present the results of a study aimed at assessing whether low and high mass stars form similarly. Our approach is (1) to examine the observed projected rotational velocities among a large sample of newly-formed stars spanning a range in mass between 0.2 and 50 M ; and (2) to search for evidence of a discontinuity in rotational properties that might indica

Vincent L. Fish, Walter F. Brisken, Loránt O. Sjouwerman

We present VLBA observations of the ground-state hydroxyl masers in W3(OH) at 0.02 km s-1 spectral resolution. Over 250 masers are detected, including 56 Zeeman pairs. Lineshapes are predominantly Gaussian or combinations of several Gaussians, with normalized deviations typically of the same magnitude as in masers in other species. Typical FWHM maser linewid

C. Maraston, E. Daddi, A. Renzini, A. Cimatti

We explore the effects of stellar population models on estimating star formation histories, ages and masses of high redshift galaxies. The focus is on the Thermally-Pulsing Asymptotic Giant Branch (TP-AGB) phase of stellar evolution, whose treatment is a source of major discrepancy among different evolutionary population synthesis. In particular, besides the

Juntai Shen, J. A. Sellwood

Recent ideas for the origin and persistence of the warps commonly observed in disc galaxies have focused on cosmic infall. We present N-body simulations of an idealized form of cosmic infall onto a disc galaxy and obtain a warp that closely resembles those observed. The inner disc tilts remarkably rigidly, indicating strong cohesion due to self-gravity. The

Gabriela Barenboim, Joseph D. Lykken

We demonstrate how much it is possible to deviate from the standard cosmological paradigm of inflation-assisted LambdaCDM, keeping within current observational constraints, and without adding to or modifying any theoretical assumptions. We show that within a minimal framework there are many new possibilities, some of them wildly different from the standard p

D. E. Harris, H. Krawczynski

Motivated by the large number of jets detected by the Chandra X-ray Observatory, and by the inverse Compton X-ray emission model (IC/CMB) for relativistic jets, we revisit two basic questions: ``If the medium that carries the jet's energy consists of hot electrons, can we use the physical length of the jet to constrain the maximum electron energy?'' and ``Wh

T. E. Tecce, L. J. Pellizza, A. E. Piatti

For several decades now, open clusters have been used to study the structure and chemical evolution of the disk of our Galaxy. Due to the fact that their ages and metallicities can be determined with relatively good precision, and since they can be observed even at great distances, they are excellent tracers of the variations in the abundance of heavy chemic

Andrea Comastri, Roberto Gilli, Guenther Hasinger

We will briefly discuss the importance of sensitive X-ray observations above a few tens of keV for a better understanding of the physical mechanisms associated to the Supermassive Black Hole primary emission in both radio quiet and radio loud AGN and to the cosmological evolution of the most obscured sources.

Philippe Jetzer, Norbert Straumann

In a recent paper Beck and Mackey [astro-ph/0603397] argue that the argument we gave in our paper [Phys. Lett. B 606, 77 (2005)] to disprove their claim that dark energy can be discovered in the Lab through noise measurements of Josephson junctions is incorrect. In particular, they emphasize that the measured noise spectrum in Josephson junctions is a conseq

J. S. Kaastra, N. Werner, J. W. A. den Herder, F. B. S. Paerels

Recently the first detections of highly ionised gas associated with two Warm-Hot Intergalactic Medium (WHIM) filaments have been reported. The evidence is based on X-ray absorption lines due to O VII and other ions observed by Chandra towards the bright blazar Mrk 421. We investigate the robustness of this detection by a re-analysis of the original Chandra L

K. M. Belotsky, M. Yu. Khlopov, K. I. Shibaev

Stable charged heavy leptons and quarks can exist and hide in elusive atoms, bound by Coulomb attraction and playing the role of dark matter. However, in the expanding Universe it is not possible to recombine all the charged particles into such atoms, and the positively charged particles, which escape this recombination, bind with electrons in atoms of anoma

S. M. Molnar, M. Birkinshaw, R. F. Mushotzky

Bright clusters of galaxies can be seen out to cosmological distances, and thus they can be used to derive cosmological parameters. Although the continuum X-ray emission from the intra-cluster gas is optically thin, the optical depth of resonant lines of ions of heavy elements can be larger than unity. In this Letter we study the feasibility of deriving dist

R. T. Edwards

I review recent results concerning the shape of drifting subpulse patterns, and the relationship to model predictions. While a variety of theoretical models exist for drifting subpulses, observers typically think in terms of a spatio-temporal model of circulating beamlets. Assuming the model is correct, geometric parameters have been inferred and animated &#

A. Pereyra, A. M. Magalhaes, C. V. Rodrigues, C. R. Silva

Aims. Core-collapse supernovae may show significant polarization that implies non-spherically symmetric explosions. We observed the type II-plateau SN 2005af using optical polarimetry in order to verify whether any asphericity is present in the supernova temporal evolution. Methods. We used the IAGPOL imaging polarimeter to obtain optical linear polarization