May 2006 arXiv papers — page 10

Roberto Mainini, Silvio Bonometto

We evaluate the mass function of virialized halos, by using Press & Schechter (PS) and/or Steth & Tormen (ST) expressions, for cosmologies where Dark Energy (DE) is due to a scalar self-interacting field, coupled with Dark Matter (DM). We keep to coupled DE (cDE) models known to fit linear observables. To implement the PS-ST approach, we start from reviewing

Carlo Guardiani, Franco Bagnoli

We present an extremely simplified model of multiple-domains polymer stretching in an atomic force microscopy experiment. We portray each module as a binary set of contacts and decompose the system energy into a harmonic term (the cantilever) and long-range interactions terms inside each domain. Exact equilibrium computations and Monte Carlo simulations qual

Christian Zier

From the results of numerical scattering experiments and simulations of a massive black hole binary in spherically symmetric and shallow cores it has been deduced that most likely the shrinking process stalls due to loss-cone depletion before emission of gravitational radiation becomes important. Here we follow a different approach and focus on the populatio

S. H. W. van der Ploeg, A. Izmalkov, Alec Maassen van den Brink, U. Huebner

We have realized controllable coupling between two three-junction flux qubits by inserting an additional coupler loop between them, containing three Josephson junctions. Two of these are shared with the qubit loops, providing strong qubit--coupler interaction. The third junction gives the coupler a nontrivial current--flux relation; its derivative (i.e., the

N. Pavlenko, I. Elfimov, T. Kopp, G. A. Sawatzky

The electronic structure of interfaces between YBa$_2$Cu$_3$O$_6$ and SrTiO$_3$ is studied using local spin density approximation (LSDA) with intra-atomic Coulomb repulsion (LSDA+U). We find a metallic state in cuprate/titanate heterostructures with the hole carriers concentrated substantially in the CuO$_2$-layers and in the first interface TiO$_2$ and SrO

Sachie Kimura, Aldo Bonasera

We discuss the alpha-muon sticking coefficient in the muon-catalysed ``in flight" d-t fusion in the framework of the Constrained Molecular Dynamics model. Especially the influence of muonic chaotic dynamics on the sticking coefficient is brought into focus. The chaotic motion of the muon affects not only the fusion cross section but also the $μ-α$ sticki

M. Ibe, Y. Shinbara, T. T. Yanagida

We reconsider the Polonyi problem in gravity-mediation models for supersymmetry (SUSY) breaking. It has been argued that there is no problem in the dynamical SUSY breaking scenarios, since the Polonyi field acquires a sufficiently large mass of the order of the dynamical SUSY-breaking scale Lamada_{SUSY}. However, we find that a linear term of the Polonyi fi

Daniel Lemire

Time series are difficult to monitor, summarize and predict. Segmentation organizes time series into few intervals having uniform characteristics (flatness, linearity, modality, monotonicity and so on). For scalability, we require fast linear time algorithms. The popular piecewise linear model can determine where the data goes up or down and at what rate. Un

J. S. Kim, B. Kahng, D. Kim, K. -I. Goh

We study the origin of scale invariance (SI) of the degree distribution in scale-free (SF) networks with a degree exponent $γ$ under coarse graining. A varying number of vertices belonging to a community or a box in a fractal analysis is grouped into a supernode, where the box mass $M$ follows a power-law distribution, $P_m(M)\sim M^{-η}$. The renormalized d

Fumio Hiai, Yoshimichi Ueda

We study the microstate free entropy of projections, and establish its basic properties similar to the self-adjoint variable case. Our main contribution is to characterize the pair-block freeness of projections by the additivity of their free entropy (Theorem 4.1), in the proof of which a transportation cost inequality plays an important role. We also briefl

Richard Lieu

Conventional treatment of cold dark matter halos employs the Navarro-Frenk-White (NFW) profile with a maximum radius set at $r=r_{200}$, where the enclosed matter has an overdensity of 200 times the critical density. The choice of $r=r_{200}$ is somewhat arbitrary. It is not the collapsed (virial) radius, but does give $r \sim$ 1 Mpc for rich clusters, which

Charles H. -T. Wang

The emergence of loop quantum gravity over the past two decades has stimulated a great resurgence of interest in unifying general relativity and quantum mechanics. Amongst a number of appealing features of this approach are the intuitive picture of quantum geometry using spin networks and powerful mathematical tools from gauge field theory. However, the pres

Juan E. Betancort-Rijo, Antonio D. Montero-Dorta

We claim that the discrepancy found between theoretical predictions for the cosmic mass function and those found in numerical simulations is due to the fact that in deriving the former all mass elements are assumed to be at the center of the object they belong to (the all-mass-at-center problem). By an appropriate treatment of this problem, using the spheric

M. S. Tame, M. Paternostro, C. Hadley, S. Bose

We study the effects of amplitude and phase damping decoherence in d-dimensional one-way quantum computation (QC). Our investigation shows how information transfer and entangling gate simulations are affected for d>=2. To understand motivations for extending the one-way model to higher dimensions, we describe how d-dimensional qudit cluster states deteriorat

Aurelien Drezet, Andreas Hohenau, Joachim R. Krenn

We analyze the origin of interference disappearance in which-path double aperture experiments. We show that we can unambiguously define an observable momentum transfer between the quantum particle and the path detector and we prove in particular that the so called ``momentum transfer free'' experiments can be in fact logically interpreted in term of

Sascha Zöllner, Hans-Dieter Meyer, Peter Schmelcher

We investigate the transition of a quasi-one-dimensional few-boson system from a weakly correlated to a fragmented and finally a fermionized ground state. Our numerically exact analysis, based on a multi-configurational method, explores the interplay between different shapes of external and inter-particle forces. Specifically, we demonstrate that the additio

Miloslav Znojil

Discrete PT-symmetric square wells are studied. Their wave functions are found proportional to classical Tshebyshev polynomials of complex argument. The compact secular equations for energies are derived giving the real spectra in certain intervals of non-Hermiticity strengths Z. It is amusing to notice that although the known square well re-emerges in the u

A. Yu. Bogdanov, Yu. I. Bogdanov, K. A. Valiev

Thermodynamical equilibrium is considered as an effect of quantum entangling of the vacuum state of a system. An explicit mathematical model of multi- particle entangled pure quantum states is developed and analyzed. In the framework, the process of measurement results in probability distributions that exactly correspond to the heat equilibrium of a system i

W. A. Berger, H. G. Miller

In the iterative algorithm recently proposed by Waxman for solving eigenvalue problems, we point out that the convergence rate may be improved. For many non-singular symmetric potentials which vanish asymptotically, a simple analytical relationship between the coupling constant of the potential and the ground state eigenvalue is obtained which can be used to

Xin-Wei Zha, Cun-Bing Huang

In this paper, an unextendible product basis and exact-entanglement bases of three qubit is given, and the properties of entanglement for exact-entanglement bases are also discussed. In addition, the bound entangled mixed state is obtained from the exact-entanglement bases.

Hyunseok Jeong

We investigate decoherence effects in the recently suggested quantum computation scheme using weak nonlinearities, strong probe coherent fields, detection and feedforward methods. It is shown that in the weak-nonlinearity-based quantum gates, decoherence in nonlinear media it can be made arbitrarily small simply by using arbitrarily strong probe fields, if p

D. Ahn, S. W. Hwang

We found that the Wigner rotation of a particle with spin 1/2, which is unitary in Minkowski spacetime, becomes non-unitary as the particle is falling onto the black hole. This implies that, from the quantum information processing point of view, any quantum information encoded in spins will be dissipated near the black hole. The gravitational field around th

M. Swartz, V. Chiochia, Y. Allkofer, C. Amsler

We show that doubly peaked electric fields are necessary to describe grazing-angle charge collection measurements of irradiated silicon pixel sensors. A model of irradiated silicon based upon two defect levels with opposite charge states and the trapping of charge carriers can be tuned to produce a good description of the measured charge collection profiles

B. Berche, C. Chatelain, C. Dufour, T. Gourieux

Many theoretical predictions derived from quantum mechanics have been confirmed experimentally during the last 80 years. However, interpretative aspects have long been subject to debate. Among them, the question of the existence of hidden variables is still open. We review these questions, paying special attention to historical aspects, and argue that one ma

Yaroslav V. Kartashov, Fangwei Ye, Lluis Torner

We elucidate the properties of mixed-gap vector surface solitons supported by the interface between a uniform medium and an optical lattice imprinted in a Kerr-type nonlinear media. The components of such mixed-gap solitons emerge from different gaps of lattice spectrum and their mutual trapping results in the formation of stable vector states. The unstable

M. Dima

The Lorentz Transformation is traditionally derived requiring the Principle of Relativity and light-speed universality. While the latter can be relaxed, the Principle of Relativity is seen as core to the transformation. The present letter relaxes both statements to the weaker, Symmetry of Reference Principle. Thus the resulting Lorentz transformation and its

Axelle Amon, Marc Lefranc

Theoretical investigations of dynamical behavior in optical parametric oscillators (OPO) have generally assumed that the cavity detunings of the interacting fields are controllable parameters. However, OPOs are known to experience mode hops, where the system jumps to the mode of lowest cavity detuning. We note that this phenomenon significantly limits the ra

J. P. Silva, A. J. Silvestre

We compare the magnetic field at the center of and the self-magnetic flux through a current-carrying circular loop, with those obtained for current-carrying polygons with the same perimeter. As the magnetic field diverges at the position of the wires, we compare the self-fluxes utilizing several regularization procedures. The calculation is best performed ut

A. Akindinov, G. Bondarenko, V. Golovin, E. Grigoriev

Further progress in building high-granular large-scale systems based on Scintillation Tiles with MRS APD light readout (START) became possible thanks to the creation of an improved version of MRS APD. The cost of the system may now be significantly reduced by using inexpensive extruded scintillator. More than 160 START samples were assembled based on this de

L. Periale, V. Peskov, A. Braem, Di Mauro

We have developed commercial prototypes of sealed gaseous detectors combined with CsI photocathodes and/or filled with photosensitive vapors. The rirst results of application of these devices for the detection of flames in daylight conditions and for the detection of scintillation lights from noble liquids will be presented. The main conclusion from our stud

M. Moriconi

We present the special theory of relativity taking the Doppler effect as the starting point, and derive several of its main effects, such as time dilation, length contraction, addition of velocities, and the mass-energy relation, and assuming energy and momentum conservation, we discuss how to introduce the 4-momentum in a natural way. We also use the Dopple

Frank X. Lee

A calculation of the mass spectrum in the baryon decuplet sector is presented using the method of QCD sum rules. Sum rules are derived for states of spin-parity 3/2+- and 1/2+ using both the conventional method and a parity-projection method. The predictive ability of the sum rules is explored by a Monte-Carlo based analysis procedure in which the three phen

Dai Lian-Rong, Zhang Zong-Ye, Yu You-Wen

The structure of $(ΩΩ)_{0^+}$ dibaryon with strangeness $s=-6$ is studied in the extended chiral SU(3) quark model, in which vector meson exchange dominates the short range interaction. The resonating group method (RGM) is adopted, in which the $ΩΩ$ and $CC$ (hidden color) channels are involved. The color screening effect and the effects of mixing of scalar

I. C. Cloet, W. Bentz, A. W. Thomas

We determine nuclear structure functions and quark distributions for $^7$Li, $^{11}$B, $^{15}$N and $^{27}$Al. For the nucleon bound state we solve the covariant quark-diquark equations in a confining Nambu--Jona-Lasinio model, which yields excellent results for the free nucleon structure functions. The nucleus is described using a relativistic shell model,

E. Litvinova, P. Ring

The Relativistic Mean Field (RMF) approach describing the motion of independent particles in effective meson fields is extended by a microscopic theory of particle vibrational coupling. It leads to an energy dependence of the relativistic mass operator in the Dyson equation for the single-particle propagator. This equation is solved in the shell-model of Dir

Prabhakar G. Vaidya, P. S. Sajini Anand

Singular Value Decomposition can be considered as an effective method for Signal Processing/especially data compression. In this short paper we investigate the application of SVD to predict data equation from data. The method is similar to nonlinear ARMA method for fitting a nonlinear equation to the data.

Michael A. Soloviev

We elucidate the relation between the two ways of formulating causality in nonlocal quantum field theory: using analytic test functions belonging to the space $S^0$ (which is the Fourier transform of the Schwartz space $\mathcal D$) and using test functions in the Gelfand-Shilov spaces $S^0_α$. We prove that every functional defined on $S^0$ has the same car

J. Gaertner, F. den Hollander, G. Maillard

We continue our study of intermittency for the parabolic Anderson equation $\partial u/\partial t = κΔu + ξu$, where $u\colon \Z^d\times [0,\infty)\to\R$, $κ$ is the diffusion constant, $Δ$ is the discrete Laplacian, and $ξ\colon \Z^d\times [0,\infty)\to\R$ is a space-time random medium. The solution of the equation describes the evolution of a ``reactant&#3

S. Gustafson, K. Nakanishi, T. -P. Tsai

We study asymptotic behaviour at time infinity of solutions close to the non-zero constant equilibrium for the Gross-Pitaevskii equation in two and three spatial dimensions. We construct a class of global solutions with prescribed dispersive asymptotic behavior, which is given in terms of the linearized evolution.

James P. Cossey, Matthew Ondrus, C. Ryan Vinroot

For any prime p, we construct, and simultaneously count, all of the complex Specht modules in a given p-block of the symmetric group which remain irreducible when reduced modulo p. We call the Specht modules with this property p-irreducible modules. Recently Fayers has proven a conjecture of James and Mathas that provides a characterization of the partitions

Fernando Schwartz

Let $(M^n,g),~n\ge 3$ be a noncompact complete Riemannian manifold with compact boundary and $f$ a smooth function on $\partial M$. In this paper we show that for a large class of such manifolds, there exists a metric within the conformal class of $g$ that is complete, has zero scalar curvature on $M$ and has mean curvature $f$ on the boundary. The problem i

Blair Dowling Sullivan

This paper is an attempt to survey the current state of our knowledge on the Caccetta-Haggkvist conjecture and related questions. In January 2006 there was a workshop hosted by the American Institute of Mathematics in Palo Alto, on the Caccetta-Haggkvist conjecture, and this paper partly originated there, as a summary of the open problems and partial results

Erik I. Broman, Jeffrey E. Steif

In this paper we will investigate dynamic stability of percolation for the stochastic Ising model and the contact process. We also introduce the notion of downward and upward $ε$-movability which will be a key tool for our analysis.

Iva Kozakova, Ronald Meester, Seema Nanda

We study the size of connected components of random nearest-neighbor graphs with vertex set the points of a homogeneous Poisson point process in ${\mathbb{R}}^d$. The connectivity function is shown to decay superexponentially, and we identify the exact exponent. From this we also obtain the decay rate of the maximal number of points of a path through the ori

Malwina J. Luczak, Colin McDiarmid

There are $n$ queues, each with a single server. Customers arrive in a Poisson process at rate $λn$, where $0<λ<1$. Upon arrival each customer selects $d\geq2$ servers uniformly at random, and joins the queue at a least-loaded server among those chosen. Service times are independent exponentially distributed random variables with mean 1. We show that the sys

Ruben Agapito, Maria Schonbek

We consider the long time behavior of solutions to the magnetohydrodynamics equations in two and three spatial dimensions. It is shown that in the absence of magnetic diffusion, if strong bounded solutions were to exist their energy cannot present any asymptotic oscillatory behavior, the diffusivity of the velocity is enough to prevent such oscillations. Whe

Brice Camus

We establish eigenfunctions estimates, in the semi-classical regime, for critical energy levels associated to an isolated singularity. For Schrödinger operators, the asymptotic repartition of eigenvectors is the same as in the regular case, excepted in dimension 1 where a concentration at the critical point occurs. This principle extends to pseudo-differenti

Dhananjay P. Mehendale

In this paper we define new numbers called the Neo-Ramsay numbers. We show that these numbers are in fact equal to the Ramsay numbers. Neo-Ramsey numbers are easy to compute and for finding them it is not necessary to check all possible graphs but enough to check only special kind of graphs having a well-defined adjacency pattern.

Peter Buergisser, Felipe Cucker, Martin Lotz

Smoothed analysis of complexity bounds and condition numbers has been done, so far, on a case by case basis. In this paper we consider a reasonably large class of condition numbers for problems over the complex numbers and we obtain smoothed analysis estimates for elements in this class depending only on geometric invariants of the corresponding sets of ill-

Mircea Crasmareanu

Generalized Lagrange-Weyl structures and compatible connections are introduced as a natural generalization of similar notions from Riemannian geometry. Exactly as in Riemannian case, the compatible connection is unique if certain symmetry conditions with respect to vertical and horizontal Christoffel symbols are imposed.

Jim Hoste, Laura Zirbel

Knots in Euclidean space which may be parameterized by a single cosine function in each coordinate are called Lissajous knots. We show that twist knots are Lissajous knots if and only if their Arf invariants are zero. We further prove that all 2-bridge knots and all (3,q)-torus knots have Lissajous projections.

Eckart Viehweg, Kang Zuo

We discuss and extend some of the results obtained in &#34;Arakelov inequalities and the uniformization of certain rigid Shimura varieties&#34; (math.AG/0503339), restricting ourselves to the two dimensional case, i.e. to surfaces Y mapping generically finite to the moduli stack of Abelian varieties. In particular we show that Y is a Hilber modular surfaces

J. E. Yukich, Yu Zhang

Let $0<a<b<\infty$ be fixed scalars. Assign independently to each edge in the lattice $\mathbb{Z}^2$ the value $a$ with probability $p$ or the value $b$ with probability $1-p$. For all $u,v\in\mathbb{Z}^2$, let $T(u,v)$ denote the first passage time between $u$ and $v$. We show that there are points $x\in\mathbb{R}^2$ such that the ``time constant&#39;&#39;

Toshiyuki Abe

We construct an irrational C_2-cofinite vertex operator algebra associatted to a finite dimensional vector space with a nondegenerate skew-symmetric bilinear form. We also classify its equivalence classes of irreducible modules and determine its automorphism group.

Tsachik Gelander, Yair Glasner

We give a complete characterization of countable primitive groups in several settings including linear groups, subgroups of mapping class groups, groups acting minimally on trees and convergence groups. The latter category includes as a special case Kleinian groups as well as subgroups of word hyperbolic groups. As an application we calculate the Frattini su

Alexander Gnedin, Jim Pitman, Marc Yor

A random composition of $n$ appears when the points of a random closed set $\widetilde{\mathcal{R}}\subset[0,1]$ are used to separate into blocks $n$ points sampled from the uniform distribution. We study the number of parts $K_n$ of this composition and other related functionals under the assumption that $\widetilde{\mathcal{R}}=ϕ(S_{\bullet})$, where $(S_t

Abhijit Champanerkar, Ilya Kofman, Eric Patterson

We complete the project begun by Callahan, Dean and Weeks to identify all knots whose complements are in the SnapPea census of hyperbolic manifolds with seven or fewer tetrahedra. Many of these ``simple&#39;&#39; hyperbolic knots have high crossing number. We also compute their Jones polynomials.

B. A. Robson, S. H. Sutanto

The transition probabilities for the components of both the Balmer and Lyman $α$-lines of hydrogenic atoms are calculated for the nonrelativistic Schrodinger theory, the Dirac theory and the recently developed eight-component formalism. For large $Z$ it is found that all three theories give significantly different results.

Michael A. Soloviev

A new, more general derivation of the spin-statistics and PCT theorems is presented. It uses the notion of the analytic wave front set of (ultra)distributions and, in contrast to the usual approach, covers nonlocal quantum fields. The fields are defined as generalized functions with test functions of compact support in momentum space. The vacuum expectation

G. A. Navarro, R. Sassot

We compare constraints on the gluon polarization in the nucleon obtained in next to leading order global QCD fits to polarized deep inelastic scattering data with those coming from observables more directly linked to the gluon polarization, such as the double spin asymmetry measured by Phenix at RHIC, and high-pT hadron production studied by COMPASS

Guido Marandella

We show how precision electroweak data, assuming CP conservation and flavor universality, despite being sensitive to 20 dimension 6 operators, constrain severely only 9 combinations of them. We define a set of 7 oblique parameters $\hat S, \hat T, \hat U, V, X,W,Y$ which fully describe corrections to the leptonic observables. We add two additional parameters

Giuseppe Marchesini

This is a working progress report on the attempt by Yuri Dokshitzer, Gavin Salam and myself to relate the small-$x$ behaviour of the anomalous dimensions in the time- and space-like cases. This relation is based on a ``reciprocity respecting equation&#39;&#39; we propose

S. Tatur, J. Bartelski

We assume that all quark and lepton $3 \times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not only less non-zero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one di

A. L. Ayala Filho, C. Brenner Mariotto, V. P. Goncalves

In this paper we estimate the influence of the shadowing effect and initial state parton energy loss in the quarkonium production at HERA-B. We analyze the $x_F$ behavior of the effective exponent $α(x_F)$ and present a comparison with the preliminary HERA-B data for $J/Ψ$ production. Moreover, we estimate the magnitude of these effects in the $J/Ψ$ producti

H. -U. Martyn

A study of various SUSY scenarios is presented in which the lightest supersymmetric particle is the gravitino $\sG$ and the next-to-lightest supersymmetric particle is a scalar tau $\stau$ with lifetimes ranging from seconds to years. Gravitinos are interesting dark matter candidates which can be produced in decays of heavier sparticles at the International

Rajiv V. Gavai, Sourendu Gupta

Fluctuations of conserved quantities in heavy-ion collisions have been argued to be diagnostic tools for the nature of the produced phase. These can be related to the predictions of quark number susceptibilities (QNS) from lattice QCD. Using the diagonal QNS, we extracted the Wroblewski parameter in a dynamical QCD computation. Our results on the cross corre

H. Jallouli, H. Sazdjian

The energy and decay width of the pi-K atom are evaluated in the framework of the quasipotential-constraint theory approach. The main electromagnetic and isospin symmetry breaking corrections to the lowest-order formulas for the energy shift from the Coulomb binding energy and for the decay width are calculated. They are estimated to be of the order of a few

Alejandro Ayala, Adnan Bashir, Alfredo Raya, Eduardo Rojas

We study the dynamical generation of masses for fundamental fermions in quenched quantum electrodynamics in the presence of weak magnetic fields using Schwinger-Dyson equations. Contrary to the case where the magnetic field is strong, in the weak field limit the coupling should exceed certain critical value in order for the generation of masses to take place

M. Ablikim et al.

Using the BES-II detector at the BEPC Collider, we measured the lowest order cross sections and the $R$ values ($R=σ^0_{e^+e^- \to {\rm hadrons}}/σ^0_{e^+e^- \to μ^+μ^-}$) for inclusive hadronic event production at the center-of-mass energies of 3.650 GeV, 3.6648 GeV and 3.773 GeV. The results lead to $\bar R_{uds}=2.224\pm 0.019\pm 0.089$ which is the avera

J. S Ricol

The purpose of the NEMO3 experiment is to detect neutrinoless double beta decay in order to determine the nature of neutrino and its absolute mass. We analysed the 389 effective days of data from the $\sim 7$ kg of $^{100}$Mo and $\sim 1$ kg of $^{82}$Se and obtained the following limits on the half-life for the \bb process: $T_{1/2}(β\beta0 ν) > 4.6 \times

BES Collaboration, M. Ablikim

Using the data of about 33 pb$^{-1}$ collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we have studied the exclusive semileptonic decays $D^+ \to K^-π^+ e^+ν_e$, $D^0 \to \bar K^0π^-e^+ν_e$, $D^+ \to \bar K^{*0}e^+ν_e$ and $D^0 \to K^{*-}e^+ν_e$. The absolute branching fractions for the decays are measured to be ${BF}(D^+ \to K

A. A. Coley, S. Hervik, W. C. Lim

We study perfect fluid cosmological models with a constant equation of state parameter $γ$ in which there are two naturally defined time-like congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities,

Delia Ionescu

In the framework of Einstein&#39;s General Relativity Theory and of the Relativistic Theory of Gravitation, the equations governing the trajectories of charged particles in the field created by a charged mass point are given. An analysis of the shape of the trajectories in both theories is presented. The first and the second order approximate solutions of th

Feng Luo, Hongya Liu

We propose an idea in spectroscopy to search for extra spatial dimensions as well as to detect the possible deviation from Newton&#39;s inverse-square law at small scale, and we take high-Z hydrogenic systems and muonic atoms as illustrations. The relevant experiments might help to explore more than two extra dimensions scenario in ADD&#39;s brane world mode

Christine A. Kelley, Deepak Sridhara, Joachim Rosenthal

Pseudocodewords of q-ary LDPC codes are examined and the weight of a pseudocodeword on the q-ary symmetric channel is defined. The weight definition of a pseudocodeword on the AWGN channel is also extended to two-dimensional q-ary modulation such as q-PAM and q-PSK. The tree-based lower bounds on the minimum pseudocodeword weight are shown to also hold for q

Nan Liu, Sennur Ulukus

We investigate the optimal performance of dense sensor networks by studying the joint source-channel coding problem. The overall goal of the sensor network is to take measurements from an underlying random process, code and transmit those measurement samples to a collector node in a cooperative multiple access channel with imperfect feedback, and reconstruct

Abhishek Parakh

This paper proposes an algorithm for oblivious transfer using elliptic curves. Also, we present its application to chosen one-out-of-two oblivious transfer.

Johan Bollen, Herbert Van de Sompel

Although recording of usage data is common in scholarly information services, its exploitation for the creation of value-added services remains limited due to concerns regarding, among others, user privacy, data validity, and the lack of accepted standards for the representation, sharing and aggregation of usage data. This paper presents a technical, standar

Diane I. Hillmann, Stuart A. Sutton, Jon Phipps, Ryan Laundry

The NSDL Metadata Registry is designed to provide humans and machines with the means to discover, create, access and manage metadata schemes, schemas, application profiles, crosswalks and concept mappings. This paper describes the general goals and architecture of the NSDL Metadata Registry as well as issues encountered during the first year of the project&#

Emina Torlak, Marten van Dijk, Blaise Gassend, Daniel Jackson

Knowledge flow analysis offers a simple and flexible way to find flaws in security protocols. A protocol is described by a collection of rules constraining the propagation of knowledge amongst principals. Because this characterization corresponds closely to informal descriptions of protocols, it allows a succinct and natural formalization; because it abstrac

Daowen Qiu

Fuzzy {\it discrete event systems} (DESs) were proposed recently by Lin and Ying [19], which may better cope with the real-world problems with fuzziness, impreciseness, and subjectivity such as those in biomedicine. As a continuation of [19], in this paper we further develop fuzzy DESs by dealing with supervisory control of fuzzy DESs. More specifically, (i)

Adam L. Buchsbaum, Alon Efrat, Shaili Jain, Suresh Venkatasubramanian

Given a set of objects with durations (jobs) that cover a base region, can we schedule the jobs to maximize the duration the original region remains covered? We call this problem the sensor cover problem. This problem arises in the context of covering a region with sensors. For example, suppose you wish to monitor activity along a fence by sensors placed at

Victor V. Kryssanov, Frank J. Rinaldo, Evgeny L. Kuleshov, Hitoshi Ogawa

Modeling human dynamics responsible for the formation and evolution of the so-called social networks - structures comprised of individuals or organizations and indicating connectivities existing in a community - is a topic recently attracting a significant research interest. It has been claimed that these dynamics are scale-free in many practically important

A. G. Green, J. E. Moore, S. L. Sondhi, A. Vishwanath

Systems near to quantum critical points show universal scaling in their response functions. We consider whether this scaling is reflected in their fluctuations; namely in current-noise. Naive scaling predicts low-temperature Johnson noise crossing over to noise power $\propto E^{z/(z+1)}$ at strong electric fields. We study this crossover in the metallic sta

S. I. Kim, A. Gurevich, X. Song, X. Li

We report on the thickness dependence of the superconducting characteristics including critical current Ic, critical current density Jc, transition temperature Tc, irreversibility field Hirr, bulk pinning force plot Fp(H), and the normal state resistivity curve measured after successive ion milling of ~ 1 um thick high Ic YBa2Cu3O7-x films made by an ex situ

Ruslan Prozorov, Russell W. Giannetta

This topical review summarizes various features of magnetic penetration depth in unconventional superconductors. Precise measurements of the penetration depth as a function of temperature, magnetic field and crystal orientation can provide detailed information about the pairing state. Examples are given of unconventional pairing in hole- and electron-doped c

S. Kolesnik, B. Dabrowski, J. Mais, M. Majjiga

We report on the magnetic, resistive, and structural studies of perovskite La$_{1/3}$Sr$_{2/3}$CoO$_{3-δ}$. By using the relation of synthesis temperature and oxygen partial pressure to oxygen stoichiometry obtained from thermogravimetric analysis, we have synthesized a series of samples with precisely controlled $δ=0.00-0.49$. These samples show three struc

Maurice Courbage, Seyed Majid Saberi Fathi

Entropy functionals are computed for non-stationary distributions of particles of Lorentz gas and hard disks. The distributions consisting of beams of particles are found to have the largest amount of entropy and entropy increase. The computations show exponentially monotonic increase during initial time of rapid approach to equilibrium. The rate of entropy

Blandine Gueslin, Laurence Talini, Benjamin Herzhaft, Yannick Peysson

We have studied the flow induced by a macroscopic spherical particle settling in a Laponite suspension that exhibits a yield-stress, thixotropy and shear-thinning. We show that the fluid thixotropy (or aging) induces an increase with time of both the apparent yield stress and shear-thinning properties but also a breaking of the flow fore-aft symmetry predict

Emile Hoskinson, Yuki Sato, Richard Packard

Matter-wave interferometers reveal some of the most fascinating phenomena of the quantum world. Phase shifts due to rotation (the Sagnac effect) for neutrons, free atoms and superfluid 3He reveal the connection of matter waves to a non-rotating inertial frame. In addition, phase shifts in electron waves due to magnetic vector potentials (the Aharonov-Bohm ef

A. T. Zayak, X. Huang, J. B. Neaton, Karin M. Rabe

Using density functional theory within the local spin density approximation, structural, electronic and magnetic properties of SRO are investigated. We examine the magnitude of the orthorhombic distortion in the ground state and also the effects of applying epitaxial constraints, whereby the influence of large (in the range of $\pm 4%$) in-plane strain resul

B. H. Hamadani, D. A. Corley, J. W. Ciszek, J. M. Tour

We have studied charge injection across the metal/organic semiconductor interface in bottom-contact poly(3-hexylthiophene) (P3HT) field-effect transistors, with Au source and drain electrodes modified by self-assembled monolayers (SAMs) prior to active polymer deposition. By using the SAM to engineer the effective Au work function, we markedly affect the cha

Andrea Fubini, Stephan Haas, Tommaso Roscilde, Valerio Tognetti

Entanglement represents a pure quantum effect involving two or more particles. Spin systems are good candidates for studying this effect and its relation with other collective phenomena ruled by quantum mechanics. While the presence of entangled states can be easily verified, the quantitative estimate of this property is still under investigation. One of the

A. F. Mota, A. J. Silvestre, P. M. Sousa, O. Conde

This work reports on the synthesis of CrO2 thin films by atmospheric pressure CVD using chromium trioxide (CrO3) and oxygen. Highly oriented (100) CrO2 films containing highly oriented (0001) Cr2O3 were grown onto Al2O3(0001) substrates. Films display a sharp magnetic transition at 375 K and a saturation magnetization of 1.92 Bohr magnetons per f.u., close t

I. Avgin, M. Winokur, D. L. Huber

We investigate localized exciton states in pi-conjugated polymers with finite torsion. The localized states are associated with a perturbed transfer integral for which the magnitude of cosine of the torsion angle exceeds the magnitude of the corresponding cosine of the unperturbed system. The localized state energy is calculated as a function of the ratio of

Ronan Lefort, Vincent Caron, Jean-François Willart, Marc Descamps

We report for the first time real time in situ and quantitative measurements of the mutarotation reaction of lactose in the solid state. The experiments have been performed by 13C NMR. We show that mutarotation is initiated on heating the amorphous state, and reaches chemical equilibrium close above the glass transition temperature Tg. We do not observe this

N. Popovici, M. L. Parames, R. C. da Silva, O. Monnereau

Chromium oxides, CrxOy, are of great interest due to the wide variety of their technological applications. Among them, CrO2 has been extensively investigated in recent years because it is an attractive compound to be used in spintronic heterostructures. However, its synthesis at low temperatures has been a difficult task due to the metastable nature of this

J. L. Gavartin, D. Munoz Ramo, A. L. Shluger, G. Bersuker

We calculated the optical excitation and thermal ionization energies of oxygen vacancies in m-HfO$_2$ using atomic basis sets, a non-local density functional and periodic supercell. The thermal ionization energies of negatively charged V$^-$ and V$^{2-}$ centres are consistent with values obtained by the electrical measurements. The results suggest that nega

P. M. Sousa, A. J. Silvestre, N. Popovici1, O. Conde

This work reports on the synthesis of chromium (III, IV) oxides films by KrF laser-assisted CVD. Films were deposited onto sapphire substrates at room temperature by photodissociation of Cr(CO)6 in dynamic atmospheres containing oxygen and argon. A study of the processing parameters has shown that partial pressure ratio of O2 to Cr(CO)6 and laser fluence are

D. Bolle, R. Heylen

The inclusion of a macroscopic adaptive threshold is studied for the retrieval dynamics of layered feedforward neural network models with synaptic noise. It is shown that if the threshold is chosen appropriately as a function of the cross-talk noise and of the activity of the stored patterns, adapting itself automatically in the course of the recall process,