July 2004 arXiv papers — page 8

L. F. Wei, Yu-xi Liu, Franco Nori

We propose an effective scheme for manipulating quantum information stored in a superconducting nanocircuit. The Josephson qubits are coupled via their separate interactions with an information bus, a large current-biased Josephson junction treated as an oscillator with adjustable frequency. The bus is sequentially coupled to only one qubit at a time. Distan

Christian Rummel, Helmut Hofmann

We address the problem of collective motion across a barrier like encountered in fission. A formula for the quantal decay rate is derived which bases on a recently developed variational approach for functional integrals. This formula can be applied to low temperatures that have not been accessible within the former PSPA type approach. To account for damping

Christian Rummel, Helmut Hofmann

For the calculation of the partition function $\mathcal{Z}$ of small, isolated and interacting many body systems an improvement with respect to previous formulations is presented. By including anharmonicities and employing a variational approach quantum effects can be treated even at very low temperatures. In order to test its accuracy the novel approach is

Sang-Jin Sin, Ismail Zahed

We study the non-linear propagation of radiation in {\cal N=4} SYM at zero and finite temperature using the refined radius/scale duality in AdS/CFT. We argue that a pulse radiation by a quark at the boundary should be described holographically by a "point like object" passing through the center of the AdS bulk. We find that at finite temperature, the

P. Amram, C. Mendes de Oliveira, H. Plana, C. Balkowski

We have obtained high spectral resolution (R = 45900) Fabry-Perot velocity maps of the Hickson Compact Group HCG 31 in order to revisit the important problem of the merger nature of the central object A+C and to derive the internal kinematics of the candidate tidal dwarf galaxies in this group. Our main findings are: (1) double kinematic components are prese

Gilbert Levitt, Martin Lustig

We show that every automorphism $α$ of a free group $F_k$ of finite rank $k$ has {\it asymptotically periodic} dynamics on $F_k$ and its boundary $\partial F_k$: there exists a positive power $α^q$ such that every element of the compactum $F_k \cup \partial F_k$ converges to a fixed point under iteration of $α^q$.

B. Kerbikov

The wave equation is derived for quark pairs in color superconductor in the regime of low density / strong coupling.

Afshin Shafiee, Feryal Safinejad, Farnoush Naqsh

In Brukner and Zeilinger's interpretation of quantum mechanics, information is introduced as the most fundamental notion and the finiteness of information is considered as an essential feature of quantum systems. They also define a new measure of information which is inherently different from the Shannon information and try to show that the latter is not

A. Faggionato, H. Schulz-Baldes, D. Spehner

We consider a random walk on the support of a stationary simple point process on $R^d$, $d\geq 2$ which satisfies a mixing condition w.r.t.the translations or has a strictly positive density uniformly on large enough cubes. Furthermore the point process is furnished with independent random bounded energy marks. The transition rates of the random walk decay e

Reginald T. Cahill

The new `quantum-foam in-flow' theory of gravity has explained numerous so-called gravitational anomalies, particularly the `dark matter' effect which is now seen to be a dynamical effect of space itself, and whose strength is determined by the fine structure constant, and not by Newton's gravitational constant G. Here we show an experimentally s

Norio Konno, Xia Ma

We study the one-dimensional two-state totalistic probabilistic cellular automata (TPCA) having an absorbing state with long-range interactions, which can be considered as a natural extension of the Domany-Kinzel model. We establish the conditions for existence of a site-bond representation and self-dual property. Moreover we present an expression of a set-t

JM Geremia

Several proposed techniques for distinguishing between optical coherent states are analyzed under a physically realistic model of photodetection. Quantum error probabilities are derived for the Kennedy receiver, the Dolinar receiver and the unitary rotation scheme proposed by Sasaki and Hirota for sub-unity detector efficiency. Monte carlo simulations are pe

Alejandra Valencia, Giuliano Scarcelli, Yanhua Shih

We report a proof-of-principle experiment on distant clock synchronization. Besides the achievement of picosecond resolution at 3 kilometer distance, this experiment demonstrated a novel concept for high accuracy non-local timing and positioning based on the quantum feature of entangled states.

Philippe Hyafil, John Mozley, Aurelien Perrin, Julien Tailleur

We present a way to trap a single Rydberg atom, make it long-lived and preserve an internal coherence over time scales reaching into the minute range. We propose to trap using carefully designed electric fields, to inhibit the spontaneous emission in a non resonant conducting structure and to maintain the internal coherence through a tailoring of the atomic

Alejandra Valencia, Maria V. Chekhova, Alexei Trifonov, Yanhua Shih

We report an experimental study of group-velocity dispersion effect on an entangled two-photon wavepacket, generated via spontaneous parametric down-conversion and propagating through a dispersive medium. Even in the case of using CW laser beam for pump, the biphoton wavepacket and the second-order correlation function spread significantly. The study and und

Sudhir Kumar Singh, R. Srikanth

A restriction on quantum secret sharing (QSS) that comes from the no-cloning theorem is that any pair of authorized sets in an access structure should overlap. From the viewpoint of application, this places an unnatural constraint on secret sharing. We present a generalization, called assisted QSS (AQSS), where access structures without pairwise overlap of a

Fay Dowker, Joe Henson

We present a spontaneous collapse model of a field theory on a 1+1 null lattice, in which the causal structure of the lattice plays a central role. Issues such as ``locality,'' ``non-locality'' and superluminal signaling are addressed in the context of the model which has the virtue of extreme simplicity. The formalism of the model is related

Elizabeth S. Allman, John A. Rhodes

Changing base composition during the evolution of biological sequences can mislead some of the phylogenetic inference techniques in current use. However, detecting whether such a process has occurred may be difficult, since convergent evolution may lead to similar base frequencies emerging from different lineages. To study this situation, algebraic models of

Reginald T. Cahill

It is shown that a new quantum-foam in-flow theory of gravity is mathematically equivalent to the General Relativity theory of gravity for the operation of the Global Positioning System (GPS). The differences between the two theories become experimentally evident in other situations such as in the so-called `dark matter' effect, in the observation of abs

J. -F. Yang

The renormalization of EFT for nucleon-nucleon scattering in nonperturbative regimes is investigated in a compact parametrization of the $T$-matrix. The key difference between perturbative and nonperturbative renormalization is clarified. The underlying theory perspective and the 'fixing' of the prescriptions for the $T$-matrix from physical boundary

J. -F. Yang

The renormalization of EFT for nucleon-nucleon scattering in nonperturbative regimes is investigated in a compact parametrization of the $T$-matrix. The key difference between perturbative and nonperturbative renormalization is clarified. The underlying theory perspective and the 'fixing' of the prescriptions for the $T$-matrix from physical boundary

Malgorzata Kasprzak

The work presented in this thesis forms part of a program at the Paul Scherrer Institute (PSI) to construct a high intensity superthermal ultra-cold neutron (UCN) source based on solid deuterium as UCN production medium. We carried out a set of experiments to gain a better understanding of the properties and the behaviour of solid deuterium as a cold neutron

Tounsia Benzekri, Cristel Chandre, Ricardo Lima, Michel Vittot

In this paper, we present a model describing the time evolution of two dimensional surface waves in gravity and infinite depth. The model of six interacting modes derives from the normal form of the system describing the dynamics of surface waves and is governed by a Hamiltonian system of equations of cubic order in the amplitudes of the waves. We derive a H

Massimiliano Guzzo, Elena Lega, Claude Froeschle'

We provide numerical evidence of global diffusion occurring in slightly perturbed integrable Hamiltonian systems and symplectic maps. We show that even if a system is sufficiently close to be integrable, global diffusion occurs on a set with peculiar topology, the so--called Arnold web, and is qualitatively different from Chirikov diffusion, occurring in mor

Gonzalo Alvarez, Shujun Li, F. Montoya, M. Romera

This paper describes the security weaknesses of a recently proposed secure communication method based on chaotic masking using projective synchronization of two chaotic systems. We show that the system is insecure and how to break it in two different ways, by high-pass filtering and by generalized synchronization.

Massimo Falcioni, Luigi Palatella, Angelo Vulpiani

We discuss the connection between the Kolmogorov-Sinai entropy, $h_{KS}$, and the production rate of the coarse grained Gibbs entropy, $r_G$. Detailed numerical computations show that the (often accepted) identification of the two quantities does not hold in systems with intermittent behavior and/or very different characteristic times and in systems presenti

S. V. Kryukov

We investigate quantum integrals of motion in the sine-Gordon, Zhiber-Shabat and similar systems. When the coupling constants in these models take special values a new quantum symmetry appears. In those cases, correlation functions can be obtained, and they have a power law behavior.

Oliver Jahn, V. V. Sreedhar, Amitabh Virmani

It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL(2,R) and the static Galilei group G. This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. I

N. Zenine, S. Boukraa, S. Hassani, J-M. Maillard

Using an expansion method in the variables $ x_i$ that appear in the $(n-1)$-dimensional integrals representing the $n$-particle contribution to the Ising square lattice model susceptibility $χ$, we generate a long series of coefficients for the 3-particle contribution $χ^{(3)}$, using a $ N^4$ polynomial time algorithm. We give the Fuchsian differential equ

R. Schrader, H. Schulz-Baldes, A. Sedrakyan

Products of random matrices associated to one-dimensional random media satisfy a central limit theorem assuring convergence to a gaussian centered at the Lyapunov exponent. The hypothesis of single parameter scaling states that its variance is equal to the Lyapunov exponent. We settle discussions about its validity for a wide class of models by proving that,

Wouter Kager, Bernard Nienhuis, Leo P. Kadanoff

In this note, we solve the Loewner equation in the upper half-plane with forcing function xi(t), for the cases in which xi(t) has a power-law dependence on time with powers 0, 1/2 and 1. In the first case the trace of singularities is a line perpendicular to the real axis. In the second case the trace of singularities can do three things. If xi(t)=2*(kappa*t

Brian Osserman

Using limit linear series and a result controlling degeneration from separable maps to inseparable maps, we give a formula for the number of self-maps of the projective line with ramification to order e_i at general points P_i, in the case that all e_i are less than the characteristic. Unlike the case of characteristic 0, the answer is not given by Schubert

G. Bande, P. Ghiggini, D. Kotschick

We prove Gray--Moser stability theorems for complementary pairs of forms of constant class defining symplectic pairs, contact-symplectic pairs and contact pairs. We also consider the case of contact-symplectic and contact-contact structures, in which the constant class condition on a one-form is replaced by the condition that its kernel hyperplane distributi

G. Bande, D. Kotschick

We study the geometry of manifolds carrying symplectic pairs consisting of two closed 2-forms of constant ranks, whose kernel foliations are complementary. Using a variation of the construction of Boothby and Wang we build contact-symplectic and contact pairs from symplectic pairs.

Pierre Matet, Saharon Shelah

Let kappa a regular uncountable cardinal and lambda a cardinal >kappa, and suppose lambda^{<kappa} is less than the covering number for category cov(M_{kappa,kappa}). Then (a) I_{kappa,lambda}^+ -->^kappa (I_{kappa, lambda}^+,omega +1)^2, (b) I_{kappa, lambda}^+ -->^kappa [I_{kappa, lambda}^+]_{kappa^+}^2 if kappa is a limit cardinal, and (c) I_{kappa, lambd

S. V. Ludkovsky

This article is devoted to the investigation of semidirect products of groups of loops and groups of diffeomorphisms of finite and infinte dimensional real, complex and quaternion manifolds. Necessary statements about quaternion manifolds with quaternion holomorphic transition mappings between charts of atlases are proved. Unitary representations of these gr

Stefan Ufer

We consider an interesting class of braidings defined by a combinatorial property in an earlier paper. We show that it consists exactly of those braidings that come from certain Yetter-Drinfeld module structures over pointed Hopf algebras with abelian coradical. As a tool we define a reduced version of the FRT construction. For braidings induced by U_q(g)-mo

Yuri A. Kordyukov

The main result of the paper is Egorov&#39;s theorem for transversally elliptic operators on compact foliated manifolds. This theorem is applied to describe the noncommutative geodesic flow in noncommutative geometry of Riemannian foliations.

Oana Drăgulete, Liviu Ornea

We complete the reduction of Sasakian manifolds with the non-zero case by showing that Willett&#39;s contact reduced space is compatible with the Sasakian structure. We then prove the compatibility of the non-zero Sasakian (in particular, contact) reduction with the reduction of the Kähler (in particular, symplectic) cone. We provide examples obtained by tor

Robert Rumely, Matthew Baker

This is a set of expanded lecture notes from the Berkovich Space seminar held at the University of Georgia during Spring, 2004. The purpose of the notes is to provide a non-technical introduction to Berkovich spaces, and to develop the foundations for analysis on the Berkovich projective line, with a view toward applications in dynamics. After describing the

N. Joshi, A. V. Kitaev

We develop a qualitative theory for real solutions of the equation $y&#39;&#39;=6y^2 -x$. In this work a restriction $x\leq0$ is assumed. An important ingredient of our theory is the introduction of several new transcendental functions of one, two, and three variables that describe different properties of the solutions. In particular, the results obtained al

Toshiro Kuwabara

The symmetric coinvariant algebra $C[x_1, dots, x_n]_{S_n}$ is the quotient algebra of the polynomial ring by the ideal generated by symmetric polynomials vanishing at the origin. It is known that the algebra is isomorphic to the regular representation of $S_n$. Replacing $C[x]$ with $A = C[x,y]/(xy)$, we introduce another symmetric coinvariant algebra $A^{o

Camille Laurent-Gengoux, Ping Xu

We study the prequantization of quasi-presymplectic groupoids and their Hamiltonian spaces using $S^1$-gerbes. We give a geometric description of the integrality condition. As an application, we study the prequantization of the quasi-Hamiltonian $G$-spaces of Alekseev--Malkin--Meinrenken.

Ping Xu

We introduce quasi-symplectic groupoids and explain their relation with momentum map theories. This approach enables us to unify into a single framework various momentum map theories, including the ordinary Hamiltonian $G$-spaces, Lu&#39;s momentum maps of Poisson group actions, and group valued momentum maps of Alekseev--Malkin--Meinrenken. More precisely,

Alexander Gnedin, Jim Pitman

A new class of random composition structures (the ordered analog of Kingman&#39;s partition structures) is defined by a regenerative description of component sizes. Each regenerative composition structure is represented by a process of random sampling of points from an exponential distribution on the positive halfline, and separating the points into clusters

Susumu Ariki

Let $W$ be a finite Weyl group of classical type which may not be irreducible, $F$ an algebraically closed field, $q$ an invertible element of $F$. We denote by $\mathcal H_W(q)$ the associated Hecke algebra. If $q=1$ then it is $FW$ and we know the representation type. Thus, we assume that $q\ne 1$. Let $P_W(x)$ be the Poincare polynomial of $W$. It is well

Stephen G. Naculich, Howard J. Schnitzer

The Seiberg-Witten solution plays a central role in the study of N=2 supersymmetric gauge theories. As such, it provides a proving ground for a wide variety of techniques to treat such problems. In this review we concentrate on the role of IIA string theory/M theory and the Dijkgraaf-Vafa matrix model, though integrable models and microscopic instanton calcu

R. Vogt

In peripheral relativistic heavy ion collisions at the Large Hadron Collider, jet+jet and photon+jet final states can be produced when a photon from the virtual photon field surrounding the nucleus interacts with a parton in the opposite nucleus (direct production). The virtual photon may also fluctuate into states with multiple gluons and q-qbar pairs (reso

A. Rubbia

Massive underground detectors can be considered as sort of observatories for rare physics phenomena like astrophysical neutrino detection and nucleon decay searches. We briefly overview the past tracking calorimeters developed for nucleon decay searches. We then discuss the two technologies which are discussed today for potential future applications: Water C

F. De Fazio

I briefly review the experimental observations concerning the charmed mesons $D_{sJ}^*(2317)$, $D_{sJ}(2460)$ and survey on some of the interpretations proposed in order to understand their nature. I present an analysis of their decay modes in the hypothesis that they can be identified with the scalar and axial vector $s_\ell^P={1 \over 2}^+$ states of $c{\b

Wojciech Broniowski, Enrique Ruiz Arriola

The Kwiecinski evolution of unintegrated parton distributions (UPDs) in the transverse-coordinate space is analyzed with the help of the Mellin transform. Numerical results are presented for the unintegrated pion distributions with a simple valence-like initial condition at the low scale, which follows from chiral large-Nc quark models. The effect of spreadi

C. S. Fischer, F. Llanes-Estrada, R. Alkofer

We summarise results on the infrared behaviour of Landau gauge QCD from the Green&#39;s functions approach and lattice calculations. Approximate, nonperturbative solutions for the ghost, gluon and quark propagators as well as first results for the quark-gluon vertex from a coupled set of Dyson-Schwinger equations are compared to quenched and unquenched latti

Daniele Pedrini

To write a review on charm decays is not an easy task because of the large amount (fortunately!) of experimental results in the recent years. I was forced to make a selection of topics. I am going to discuss with the eyes of an experimentalist: D0-D0bar mixing, CP violation, rare decays, charm lifetimes, semileptonic decays, hadronic decays, and the big surp

Barbara Mele

In this talk, I review the main motivations for expecting new physics at the TeV energy scale, that will be explorable at the CERN Large Hadron Collider.

Amand Faessler, Th. Gutsche, Sergey Kovalenko, V. E. Lyubovitskij

We study nuclear mu-e conversion in the general framework of an effective Lagrangian approach without referring to any specific realization of the physics beyond the standard model (SM) responsible for lepton flavor violation (LFV). We examine the impact of a specific hadronization prescription on the analysis of new physics in nuclear mu-e conversion and st

Florian Girelli, Etera R. Livine

Deformed Special Relativity (DSR) is obtained by imposing a maximal energy to Special Relativity and deforming the Lorentz symmetry (more exactly the Poincaré symmetry) to accommodate this requirement. One can apply the same procedure deforming the Galilean symmetry in order to impose a maximal speed (the speed of light). This leads to a non-commutative spac

H. -J. Schmidt

We present mathematical details of several cosmological models, whereby the topological and the geometrical background will be emphasized.

Keye Martin, Prakash Panangaden

Beginning from only a countable dense set of events and the causality relation, it is possible to reconstruct a globally hyperbolic spacetime in a purely order theoretic manner. The ultimate reason for this is that globally hyperbolic spacetimes belong to a category that is equivalent to a special category of domains called interval domains.

Keye Martin, Prakash Panangaden

We prove that a globally hyperbolic spacetime with its causality relation is a bicontinuous poset whose interval topology is the manifold topology. This provides an abstract mathematical setting in which one can study causality independent of geometry and differentiable structure.

Andrei Galiautdinov

Standard general relativity fails to take into account the changes in coordinates induced by the variation of metric in the Hilbert action principle. We propose to include such changes by introducing a fundamental compensating tensor field and modifying the usual variational procedure.

Y. Janssen, S. Chang, B. K. Cho, A. Llobet

We report evidence of the absence of zero thermal expansion in well-characterized high-quality polycrystalline samples of YbGaGe. High-quality samples of YbGaGe were produced from high-purity starting elements and were extensively characterized using x-ray powder diffraction, differential thermal analysis, atomic emission spectroscopy, magnetization, and neu

G. Vignale

We show that the time-dependent particle density $n(\vec r,t)$ and the current density ${\vec j}(\vec r,t)$ of a many-particle system that evolves under the action of external scalar and vector potentials $V(\vec r,t)$ and $\vec A(\vec r,t)$ and is initially in the quantum state $|ψ(0)>$, can always be reproduced (under mild assumptions) in another many-part

V. Sih, W. H. Lau, R. C. Myers, A. C. Gossard

Time-resolved optical measurements of electron spin dynamics in modulation doped InGaAs quantum wells are used to explore electron spin coherence times and spin precession frequencies in a regime where an out of plane magnetic field quantizes the states of a two-dimensional electron gas into Landau levels. Oscillatory features in the transverse spin coherenc

Michael T. Gastner, M. E. J. Newman

We study networks that connect points in geographic space, such as transportation networks and the Internet. We find that there are strong signatures in these networks of topography and use patterns, giving the networks shapes that are quite distinct from one another and from non-geographic networks. We offer an explanation of these differences in terms of t

J. B. Neaton, C. Ederer, U. V. Waghmare, N. A. Spaldin

The ground-state structural and electronic properties of ferroelectric BiFeO$_3$ are calculated using density functional theory within the local spin-density approximation and the LSDA+U method. The crystal structure is computed to be rhombohedral with space group $R3c$, and the electronic structure is found to be insulating and antiferromagnetic, both in ex

Yongqiang Xue, Mark A. Ratner

We present a microscopic study of single-electron tunneling in nanomechanical double-barrier tunneling junctions formed using a vibrating scanning nanoprobe and a metallic nanoparticle connected to a metallic substrate through a molecular bridge. We analyze the motion of single electrons on and off the nanoparticle through the tunneling current, the displace

Jorge Iniguez, Taner Yildirim

Understanding the structural underpinnings of magnetism is of great fundamental and practical interest. Se_{1-x}Te_{x}CuO_{3} alloys are model systems for the study of this question, as composition-induced structural changes control their magnetic interactions. Our work reveals that this structural tuning is associated with the position of the supposedly dum

Xueyuan Wu, Asok K. Ray

The electronic and geometric properties of bulk fcc delta-plutonium and the quantum size effects in the surface energies and the work functions of the (001) ultra thin films (UTF) up to 7 layers have been investigated with periodic density functional theory calculations within the full-potential linearized augmented-plane wave (FP-LAPW) approach as implement

Giovanna Morigi, Shmuel Fishman

Cold ions in anisotropic harmonic potentials can form ion chains of various sizes. Here, the density of ions is not uniform, thus the eigenmodes are not phononic-like waves. We study chains of N>>1 ions and evaluate analytically the long wavelength modes and the density of states in the short wavelength limit. These results reproduce with good approximation

Jiandong Guo, Junren Shi, E. W. Plummer

A new structural phase transition has been observed at low temperatures for the one third of a monolayer (alpha phase) of Pb on Ge(111) using a variable-temperature scanning tunneling microscope. The well-known (r3xr3)R30 to (3x3) transition is accompanied by a new structural phase transition from (3x3) to a disordered phase at ~76 K. The formation of the ne

V. G. Kogan, N. V. Zhelezina

We argue that in clean high-$κ$ type II superconductors, the low temperature vortex core size (defined as the coherence length $ξ$) in high fields should decrease with increasing applied field in qualitative agreement with experimental data. Calculations are done for the Fermi sphere and cylinder (with the field parallel to the cylinder axis). The results fo

B. Bourlon, C. Miko, L. Forro, D. C. Glattli

We report on the intershell electron transport in multiwalled carbon nanotubes (MWNT). To do this, local and nonlocal four-point measurements are used to study the current path through the different shells of a MWNT. For short electrode separations $\lesssim$ 1 $μ$m the current mainly flows through the two outer shells, described by a resistive transmission

G. P. Mikitik, E. H. Brandt, M. Indenbom

As an example for a seemingly simple but actually intricate problem, the Bean critical state is studied in a superconducting strip of finite thickness d and width 2w >> d placed in an oblique magnetic field. The analytical solution is obtained to leading order in the small parameter d/w. The critical state depends on how the applied magnetic field is switche

Y. -H. Kim, U. Kuhl, H. -J. Stöckmann, P. W. Brouwer

We investigate the statistical properties of wavefunctions in an open chaotic cavity. When the number of channels in the openings of the billiard is increased by varying the frequency, wavefunctions cross over from real to complex. The distribution of the phase rigidity, which characterizes the degree to which a wavefunction is complex, and long-range correl

I. Puica, W. Lang

The excess Hall conductivity, resulting from thermal fluctuations of the superconducting order parameter, is calculated for a layered superconductor for an arbitrarily strong in-plane electric field and a perpendicular magnetic field in the frame of the time-dependent Ginzburg-Landau theory. The fluctuation Hall conductivity is suppressed in high electric fi

Balázs Dóra, Kazumi Maki, Attila Virosztek

Unconventional density wave (UDW) has been speculated as a possible electronic ground state in excitonic insulator in 1968. Recent surge of interest in UDW is partly due to the proposal that the pseudogap phase in high T_c cuprate superconductors is d-wave density wave (d-DW). Here we review our recent works on UDW within the framework of mean field theory.

Fabrizio Ferro, Piero Quarati

We show that, in stellar core plasmas, the one-body momentum distribution function is strongly dependent, at least in the high velocity regime, on the microscopic dynamics of ion elastic collisions and therefore on the effective collisional cross sections, if a random force field is present. We take into account two cross sections describing ion-dipole and i

Damien Challet, Isaac Perez Castillo

The binary Defect Combination Problem consists in finding a fully working subset from a given ensemble of imperfect binary components. We determine the typical properties of the model using methods of statistical mechanics, in particular, the region in the parameter space where there is almost surely at least one fully-working subset. Dynamic recycling of a

M. V. Feigel&#39;man, L. B. Ioffe, V. B. Geshkenbein, P. Dayal

We propose a new design for a quantum bit with four superconducting islands in the topology of a symmetric tetrahedron, uniformly frustrated with one-half flux-quantum per loop and one-half Cooper-pair per island. This structure emulates a noise-resistant spin-1/2 system in a vanishing magnetic field. The tetrahedral quantum bit combines a number of advances

Hicham Qasmi, Julien Barre&#39;, Thierry Dauxois

We consider the links between nonlinear dynamics and thermodynamics in the framework of a simple nonlinear model for DNA. Two analyses of the phase transition, either with the transfer integral approach or by considering the instability of a nonlinear particular solution, are discussed. Conversely, the computation of the largest Lyapunov exponent is obtained

Uday Kumar, K. G. Padmalekha, P. K. Mukhopadhyay, Durga Paudyal

We report here the preparation and measurements on the susceptibility, sound velocity and internal friction for Ni-Pt systems. We then compare these experimental results with the first principle theoretical predictions and show that there is reasonable agreement with experiment and theory.

J. Keller, D. A. Ryndyk

Nonequilibrium effects created by stationary current injection in layered d-wave superconductors forming a stack of intrinsic Josephson junctions are studied. Starting from a nonequilibrium Green function theory we derive microscopic expressions for the charge-imbalance (difference between electron- and hole-like quasi-particles) on the superconducting layer

F. Budde, B. J. Ruck, A. Koo, S. Granville

Ion assisted deposition (IAD) has been investigated for the growth of GaN, and the resulting films studied by x-ray diffraction and absorption spectroscopy and by transmission electron microscopy. IAD grown stoichiometric GaN consists of random-stacked quasicrystals of some 3 nm diameter. Amorphous material is formed only by incorporation of 15% or more oxyg

Helmut G. Katzgraber, L. W. Lee, A. P. Young

We study the correlation length of the two-dimensional Ising spin glass with a Gaussian distribution of interactions, using an efficient Monte Carlo algorithm proposed by Houdayer, that allows larger sizes and lower temperatures to be studied than was possible before. We find that the &#34;effective&#34; value of the bulk correlation length exponent νincreas

B. M. Peterson, K. Horne

Reverberation mapping is a proven technique that is used to measure the size of the broad emission-line region and central black hole mass in active galactic nuclei. More ambitious reverberation mapping programs that are well within the capabilities of Hubble Space Telescope could allow us to determine the nature and flow of line-emitting gas in active nucle

K. Kolb, J. Miller, E. M. Sion, J. Mikolajewska

We have applied grids of NLTE high gravity model atmospheres and optically thick accretion disk models for the first time to archival IUE and FUSE spectra of the S-type symbiotic variable EG And taken at superior spectroscopic conjunction when Rayleigh scattering should be minimal and the hot component is viewed in front of the red giant. For EG And&#39;s wi

James V. Lindesay, H. Pierre Noyes

We use general arguments to examine the energy scales for which a quantum coherent description of gravitating quantum energy units is necessary. The cosmological dark energy density is expected to decouple from the Friedman-Lemaitre energy density when the Friedman-Robertson-Walker scale expansion becomes sub-luminal, at which time the usual microscopic inte

E. M. Sion, L. Winter, J. A. Urban, G. H. Tovmassian

We explore the origin of FUSE and HST STIS far UV spectra of the dwarf nova, EY Cyg, during its quiescence using \emph{combined} high gravity photosphere and accretion disk models as well as model accretion belts. The best-fitting single temperature white dwarf model to the FUSE plus HST STIS spectrum of EY Cygni has T$_{eff} = 24,000$K, log $g = 9.0$, with

O. Benhar, V. Ferrari, L. Gualtieri

The frequencies and damping times of the non radial oscillations of neutron stars are computed for a set of recently proposed equations of state (EOS) which describe matter at supranuclear densites. These EOS are obtained within two different approaches, the nonrelativistic nuclear many-body theory and the relativistic mean field theory, that model hadronic

M. M. Dworetsky

The parameter-free model of diffusion in the atmospheres of HgMn stars (Michaud 1986; Michaud et al 1979) predicts that helium should sink below the He II ionization zone in order that diffusion of other elements may take place, and that all HgMn stars should have deficits of helium in their photospheres, with a minimum deficit of 0.3 dex. In this study, the

Y. Clénet, D. Rouan, D. Gratadour, F. Lacombe

L&#39;-band (lambda=3.8 microns) and M&#39;-band (lambda=4.8 microns) observations of the Galactic Center region, performed in 2003 at VLT (ESO) with the adaptive optics imager NACO, have lead to the detection of an infrared counterpart of the radio source Sgr A* at both wavelengths. The measured fluxes confirm that the Sgr A* infrared spectrum is dominated

Herman J. Mosquera Cuesta, Karen Fiuza

During supernova core collapse and bounce resonant active-to-active, as well as active-to-sterile, neutrino ($ν$) oscillations can take place. Over this phase weak magnetism increases antineutrino mean free paths, and thus its luminosity. Because oscillations feed mass-energy into the target $ν$ species, the large mass-squared difference between $ν$ states i

L. Pasquini, P. Bonifacio, S. Randich, D. Galli

We present the first detection of beryllium in two turnoff stars of the old, metal-poor globular cluster NGC 6397. The beryllium lines are clearly detected and we determine a mean beryllium abundance of log(Be/H)=-12.35 +/- 0.2. The beryllium abundance is very similar to that of field stars of similar Fe content. We interpret the beryllium abundance observed

Gavin Ramsay, C. M. Bridge, Mark Cropper, K. O. Mason

We present XMM-Newton observations of the eclipsing polar EP Dra which cover nearly 3 binary orbital cycles. The X-ray and UV data show evidence for a prominent dip before the eclipse which is due to the accretion stream obscuring the accretion region. The dip ingress is rapid in hard X-rays suggesting there is a highly collimated core of absorption. We find

R. Foot, R. R. Volkas

Mirror matter has been proposed as a dark matter candidate. It has several very attractive features, including automatic stability and darkness, the ability to mimic the broad features of cold dark matter while in the linear density perturbation regime, and consistency with all direct dark matter search experiments, both negative (e.g. CDMS II) and positive

Arthur M. Wolfe, J. Chris Howk, Eric Gawiser, Jason X. Prochaska

We investigate the heat source of the neutral gas comprising DLAs. Unlike the Lya forest, where the extragalactic background radiation field ionizes and heats the gas, we find that grain photoelectric heating by the FUV background is not sufficient to balance the C II 158um cooling rate inferred from DLAs. In these systems, a local energy source is required.

A. R. Beresnyak

We present results of the simulation of the intensity distribution of radio pulses from the Moon due to interaction of EeV neutrinos with lunar regolith. The radiation mechanism is of coherent Ĉerenkov radiation of the negative charge excess in the shower, known as Askar&#39;yan effect. Several realistic observational setups with ground radio telescopes are

E. Gabrielli, K. Huitu, S. Khalil

We systematically analyze the supersymmetric contributions to the mixing CP asymmetries and branching ratios of B -> Phi K(S) and B -> eta(prime) K(S) processes. We consider both gluino and chargino exchanges in a model independent way by using the mass insertion approximation method. While we adopt the QCD factorization approach for evaluating the correspon

M. Kupczynski

The entangled quantum states play a key role in quantum information. The association of the quantum state vector with each individual physical system in an attributive way is a source of many false paradoxes and inconsistencies. The paradoxes are avoided if the purely statistical interpretation (SI) of the quantum state vector is adopted. According the SI th

Bing Dong, H. L. Cui, X. L. Lei, Norman J. M. Horing

We present a theoretical analysis of the effect of inelastic electron scattering on current and its fluctuations in a mesoscopic quantum dot (QD) connected to two leads, based on a recently developed nonperturbative technique involving the approximate mapping of the many-body electron-phonon coupling problem onto a multichannel single-electron scattering pro