April 2005 arXiv papers — page 4

Sen Zhou, Meng Gao, Hong Ding, Patrick A. Lee

The electronic structure of Na$_x$CoO$_2$ revealed by recent photoemission experiments shows important deviations from band theory predictions. The six small Fermi surface pockets predicted by LDA calculations have not been observed as the associated $e_g^\prime$ band fails to cross the Fermi level for a wide range of sodium doping concentration $x$. In addi

Guido Burkard

Based on a network graph analysis of the underlying circuit, a quantum theory of arbitrary superconducting charge qubits is derived. Describing the dissipative elements of the circuit with a Caldeira-Leggett model, we calculate the decoherence and leakage rates of a charge qubit. The analysis includes decoherence due to a dissipative circuit element such as

Luca G. Molinari

Hedin's equations are solved perturbatively in zero dimension to count Feynman graphs for self-energy, polarization, propagator, effective potential and vertex function in a many-body theory of fermions with two-body interaction. Counting numbers are also obtained in the GW approximation.

C. Marois, R. Doyon, D. Nadeau, R. Racine

A near-infrared camera in use at the Canada-France-Hawaii Telescope (CFHT) and at the 1.6-m telescope of the Observatoire du Mont-Megantic is described. The camera is based on a Hawaii-1 1024x1024 HgCdTe array detector. Its main feature is to acquire three simultaneous images at three wavelengths across the methane absorption bandhead at 1.6 microns, enablin

S. G. Djorgovski

All sciences, including astronomy, are now entering the era of information abundance. The exponentially increasing volume and complexity of modern data sets promises to transform the scientific practice, but also poses a number of common technological challenges. The Virtual Observatory concept is the astronomical community's response to these challenges

Seokcheon Lee

We introduce a simple parametrization of the dark energy equation of state, ω, which is motivated from theory and recent experimental data. The theory is related to the tracker solution to alleviate the fine tuning problem. Recent experimental data indicates that the present value of ωis close to -1. We analyze the evolution of ωfrom the separation of CMB pe

Miguel A. Perez-Torres, A. Alberdi, J. M. Marcaide, M. A. Guerrero

We report on 8.4 GHz VLBI observations of SN2001gd in the spiral galaxy NGC5033 made on 26 June 2002 and 8 April 2003. Our data nominally suggests a relatively strong deceleration for the expansion of SN2001gd, but we cannot dismiss the possibility of a free supernova expansion. From our VLBI observations on 8 April 2003, we inferred a minimum total energy i

Dimitri A. Gadotti, Ronaldo E. de Souza

In order to perform a detailed study of the stellar kinematics in the vertical axis of bars, we obtained high signal-to-noise spectra along the major and minor axes of the bars in a sample of 14 face-on galaxies, and used them to determine the line of sight stellar velocity distribution, parameterized as Gauss-Hermite series. With these data, we developed a

Matteo Viel

We use LUQAS, a sample of 27 high resolution high signal-to-noise UVES quasar (QSO) spectra (Kim et al. 2004), and the Croft et al. (2002) sample together with a set of high resolution large box size hydro-dynamical simulations run with the code GADGET-II to recover the linear dark matter power spectrum at z>2 and at scales of 1-40 Mpc/h. These scales cannot

C. R. A. Augusto, C. E. Navia, M. b. Robba

This paper presents first results of an ongoing study of a possible association between muon enhancements at ground observed by the TUPI telescope and transient events such as the Sun's X-ray activity. The analysis of the observed phenomenon by using the GOES satellite archive data seems to indicate that on most cases the Ground Level Enhancements (GLEs)

Luis C. Ho

I summarize the main observational properties of low-luminosity AGNs in nearby galaxies to argue that they are the high-mass analogs of black hole X-ray binaries in the "low/hard" state. The principal characteristics of low-state AGNs can be accommodated with a scenario in which the central engine is comprised of three components: an optically thick,

Luis C. Ho

The [O II] 3727 line, a commonly used estimator of star formation rate in extragalactic surveys, should be an equally effective tracer of star formation in the host galaxies of quasars, whose narrow-line regions are expected to produce weak low-ionization emission. Quasar spectra generally show little or no [O II] emission beyond that expected from the activ

J. M. Pittard, M. S. Dobson, R. H. Durisen, J. E. Dyson

We investigate the Mach number dependence of the radiative overstability of shocks. We find that the stability of radiative shocks increases with decreasing Mach number, with the result that M=2 shocks require cooling exponents < -1.2 to be overstable. The frequency of oscillation of the fundamental mode has a strong Mach number dependence. We find that feed

D. Fargion, M. Grossi

The apparently huge energy budget of the gamma ray burst GRB 990123 led to the final collapse of the isotropic fireball model, forcing even the most skeptical to consider a beamed Jet emission correlated to a supernova (SN) explosion. Similarly the surprising giant flare from the soft gamma repeater SGR 1806-20 that occurred on 2004 December 27, may induce t

S. V. Jeffers

In this paper, size distributions of starspots extrapolated from the case of the Sun, are modelled on the eclipsing binary SV Cam to synthesise images of stellar photospheres with high spot filling factors. These spot distributions pepper the primary&#39;s surface with spots, many of which are below the resolution capabilities of eclipse mapping and Doppler

Giannotti Maurizio

The cosmological (upper) limit on the Peccei-Quinn constant, related to the primordial oscillations of the axion field, can be relaxed for a mirror axion model. The simple reason is that the mirror world is colder and so the behavior of the axion temperature-dependent mass is dominated by the contribution from the mirror sector. So the coherent oscillations

E. W. Bonning, M. Falanga

We report the first INTEGRAL timing and spectral analysis of the high mass X-ray binary source 2S 0114+65 at high energies (5-100 keV). The pulse period was found at 2.668 hr with a high pulsed fraction, ~80% in both the 20-40 keV and 40-80 keV energy bands. The spin-up trend over ~8 years was measured to be -8.9 * 10^{-7}. The hard X-ray spectrum obtained w

Silvia Mollerach, Esteban Roulet

We propose a new method to determine the dipole (and quadrupole) component of a distribution of cosmic ray arrival directions, which can be applied when there is partial sky coverage and/or inhomogeneous exposure. In its simplest version it requires that the exposure only depends on the declination, but it can be easily extended to the case of a small amplit

C. Winkelmann, E. Moulin, Yu. Bunkov, J. Genevey

Superfluid He3 at ultra-low temperatures (100 microKelvins) is a sensitive medium for the bolometric detection of particles. MACHe3 (MAtrix of Cells of Helium 3) is a project for non-baryonic dark matter search using He3 as a sensitive medium. Simulations made on a high granularity detector show a very good rejection to background signals. A multicell protot

I. R. King, L. R. Bedin, G. Piotto, S. Cassisi

Using HST ACS/WFC images, we derive the color--magnitude diagram of the old, metal-rich open cluster NGC 6791 to nearly 29th magnitude in V, which is the neighborhood of the hydrogen-burning limit.Comparison with isochrones leads to a discussion of the distance modulus, the reddening, and the age of the cluster. By making a statistical correction for field s

F. La Barbera, R. R. de Carvalho, R. Gal, G. Busarello

Color gradients in early-type galaxies contain valuable clues about their formation and evolutionary histories and mechanisms. We examine color gradients in 1,700 early-type galaxies in 159 galaxy clusters spanning a redshift range of 0.05 to 0.2. We find that color gradients strongly depend on the environment where galaxies reside, with steeper color gradie

Erik Kuulkers

The European gamma-ray observatory INTEGRAL has found a group of hard X-ray sources which are highly absorbed, i.e., with column densities higher than about 10^{23}/cm^2. Here I give an overview of this class of INTEGRAL sources. The X-ray, as well as the optical/IR, properties of these sources and their location in the sky suggest that they belong to the cl

Y. Shi, G. H. Rieke, D. C. Hines, G. Neugebauer

We report MIPS photometry of 20 radio-loud quasars and galaxies at 24 and 70 um (and of five at 160 um). We combine this sample with additional sources detected in the far infrared by IRAS and ISO for a total of 47 objects, including 23 steep spectrum Type I AGNs: radio-loud quasars and broad line radio galaxies; and 24 Type II AGNs: narrow line and weak lin

Gabriel Tellez

We complement a recent exact study by L. Samaj on the properties of a guest charge $Q$ immersed in a two-dimensional electrolyte with charges $+1/-1$. In particular, we are interested in the behavior of the density profiles and electric potential created by the charge and the electrolyte, and in the determination of the renormalized charge which is obtained

FOCUS Collaboration, J. M. Link

A high statistics measurement of the Ds+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, Ds+ -> phi(1020)pi+ and Ds+ -> \bar{K}*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5 (stat.) +/- 5.1 (syst.) fs using 8961 +/- 105 Ds+ -> phi(1020)pi+ and

Serge Reymond, Paul SanGiorgio, M. R. Beasley, Jinho Kim

We have made an experimental study of the tunneling density of states (DOS) in strong ferromagnetic thin films (CoFe) in proximity with a thick superconducting film (Nb) as a function of $d_F$, the ferromagnetic thickness. Remarkably, we find that as $d_F$ increases, the superconducting DOS exhibits a scaling behavior in which the deviations from the normal-

T. Binoth, J. Ph. Guillet, G. Heinrich, E. Pilon

We present a formalism for the calculation of multi-particle one-loop amplitudes, valid for an arbitrary number N of external legs, and for massive as well as massless particles. A new method for the tensor reduction is suggested which naturally isolates infrared divergences by construction. We prove that for N>4, higher dimensional integrals can be avoided.

A. Ashoorioon, J. L. Hovdebo, R. B. Mann

One of the firm predictions of inflationary cosmology is the consistency relation between scalar and tensor spectra. It has been argued that such a relation -if experimentally confirmed- would offer strong support for the idea of inflation. We examine the possibility that trans-Planckian physics violates the consistency relation in the framework of inflation

Hooman Davoudiasl, Patrick Huber

We study type II supernova signatures of neutrino mass generation via symmetry breaking at a scale in the range from keV to MeV. The scalar responsible for symmetry breaking can be thermalized in the supernova core and restore the symmetry. The neutrinos from scalar decays have about half the average energy of thermal neutrinos and are Bose-Einstein distribu

KTeV Collaboration, E. Abouzaid, T. Alexopoulos, M. Arenton

The Xi^0 muon semi-leptonic decay has been observed for the first time with nine identified events using the KTeV beam line and detector at Fermilab. The decay is normalized to the Xi^0 beta decay mode and yields a value for the ratio of decay rates of $(1.8^{+0.7}_{-0.5}(stat.)\pm0.2(syst.))\times 10^{-2}$. This is in agreement with the SU(3) flavor symmetr

Masahiro Nagashima, Cedric G. Lacey, Takashi Okamoto, Carlton M. Baugh

We investigate the metal enrichment of elliptical galaxies in the framework of hierarchical models of galaxy formation. The semi-analytical model we use in this Letter, which has been used to study the metal enrichment of the intracluster medium (ICM) by Nagashima et al., includes the effects of flows of gas and metals both into and out of galaxies and the p

Steven Thomas, John Ward

We propose an alternative formulation of tachyon inflation using the geometrical tachyon arising from the time dependent motion of a BPS $D3$-brane in the background geometry due to $k$ parallel $NS$5-branes arranged around a ring of radius $R $. Due to the fact that the mass of this geometrical tachyon field is $\sqrt{2/k} $ times smaller than the correspon

Asantha Cooray, Milos Milosavljevic

Using the empirical relations between the central galaxy luminosity and the halo mass, and between the total galaxy luminosity in a halo and the halo mass, we construct the galaxy luminosity function (LF). To the luminosity of the central galaxy in a halo of a given mass we assign log-normal scatter with a mean calibrated against the observations. In halos w

Ondrej Hudak, Matej Hudak

The Landau theory of 180 degrees domain walls in BaTiO3 type ferroelectric particles is presented. Results of exact description of domain walls in bulk enabled us to formulate variational approach to theory of domain walls in corresponding small particles. The depolarization field effects and the space-charge layers are taken into account in the samples of t

Marek Chrobak, Claire Kenyon, Neal E. Young

The Reverse Greedy algorithm (RGreedy) for the k-median problem works as follows. It starts by placing facilities on all nodes. At each step, it removes a facility to minimize the resulting total distance from the customers to the remaining facilities. It stops when k facilities remain. We prove that, if the distance function is metric, then the approximatio

A. Cabo, D. B. Cervantes, H. Perez Rojas, M. Socolovsky

We study the non relativistic limit of the charge conjugation operation $\cal C$ in the context of the Dirac equation coupled to an electromagnetic field. The limit is well defined and, as in the relativistic case, $\cal C$, $\cal P$ (parity) and $\cal T$ (time reversal) are the generators of a matrix group isomorphic to a semidirect sum of the dihedral grou

Laurent Baulieu, Guillaume Bossard, Alessandro Tanzini

The scalar and vector topological Yang-Mills symmetries determine a closed and consistent sector of Yang-Mills supersymmetry. We provide a geometrical construction of these symmetries, based on a horizontality condition on reducible manifolds. This yields globally well-defined scalar and vector topological BRST operators. These operators generate a subalgebr

Lawrence J. Hall, Hitoshi Murayama, Gilad Perez

Electroweak Baryogenesis, given a first order phase transition, does not work in the standard model because the quark Yukawa matrices are too hierarchical. On the other hand, the neutrino mass matrix is apparently not hierarchical. In models with neutrino mass generation at low scales, the neutrino Yukawa couplings lead to large CP-violation in the reflectio

A. Corsi, L. Piro, E. Kuulkers, L. Amati

We report on BeppoSAX simultaneous X- and gamma-ray observations of the bright GRB 990123. We present the broad-band spectrum of the prompt emission, including optical, X- and gamma-rays, confirming the suggestion that the emission mechanisms at low and high frequencies must have different physical origins. In the framework of the standard fireball model, we

Alexey A. Kovalev, Gerrit E. W. Bauer, Arne Brataas

We address two finite size effects in perpendicular transport through magnetic multilayers. When the magnetic layer thickness in spin valves becomes of the order or smaller than the spin-flip diffusion length, structural asymmetries affect the transport properties. A magnetic layer with thickness approaching the magnetic coherence length becomes transparent

S. Jadach, M. Skrzypek

We present the constrained Monte Carlo (CMC) algorithm for the QCD evolution. The constraint resides in that the total longitudinal energy of the emissions in the MC and in the underlying QCD evolution is predefined (constrained). This CMC implements exactly the full DGLAP evolution of the parton distributions in the hadron with respect to the logarithm of t

Erick Herbin, Jacques Lévy-Véhel

A lot is known about the Hölder regularity of stochastic processes, in particular in the case of Gaussian processes. Recently, a finer analysis of the local regularity of functions, termed 2-microlocal analysis, has been introduced in a deterministic frame: through the computation of the so-called 2-microlocal frontier, it allows in particular to predict the

CDF Collaboration, D. Acosta

We present a measurement of the top pair production cross section in $p\bar{p}$ collisions at $\sqrt{s}$=1.96 TeV. We collect a data sample with an integrated luminosity of 194$\pm$11 pb$^{-1}$ with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes

Ferenc Sikler

The capabilities of the CMS detector are shown and its Heavy Ion program is outlined.

S. Ouazi, J. Bobroff, H. Alloul, M. Le Tacon

Oxygen NMR is used to probe the local influence of nonmagnetic Zn and magnetic Ni impurities in the superconducting state of optimally doped high Tc YBa2Cu3O7. Zn and Ni induce a staggered paramagnetic polarization, similar to that evidenced above Tc, with a typical extension xi=3 cell units for Zn and xi>=3 for Ni. In addition, Zn is observed to induce a lo

Kiyoshi Sasaki, Shoichi Sasaki, Tetsuo Hatsuda

We study the mass spectra of excited baryons with the use of the lattice QCD simulations. We focus our attention on the problem of the level ordering between the positive-parity excited state N&#39;(1440) (the Roper resonance) and the negative-parity excited state N^*(1535). Nearly perfect parity projection is accomplished by combining the quark propagators

M. Stoilov

It is shown that in the first order gauge theories under some general assumptions gauge conditions can play the role of new local symmetry generators, while the original constraints become gauge fixing terms. It is possible to associate with this new symmetry a second BRST charge and its anticommutator with the original BRST charge is the Hodge operator of t

M. Cirasuolo, F. Shankar, G. L. Granato, G. De Zotti

We show that the observed Velocity Dispersion Function of E/S0 galaxies matches strikingly well the distribution function of virial velocities of massive halos virializing at z > 1.5, as predicted by the standard hierarchical clustering scenario in a \LambdaCDM cosmology, for a constant ratio sigma/V_vir = 0.55 \pm 0.05, close to the value expected at virial

A. Reischl, K. P. Schmidt, G. S. Uhrig

The Mott insulating phase of a one-dimensional bosonic gas trapped in optical lattices is described by a Bose-Hubbard model. A continuous unitary transformation is used to map this model onto an effective model conserving the number of elementary excitations. We obtain quantitative results for the kinetics and for the spectral weights of the low-energy excit

Takehiro Azuma, Subrata Bal, Jun Nishimura

It has been known for some time that the dynamics of k coincident D-branes in string theory is described effectively by U(k) Yang-Mills theory at low energy. While these configurations appear as classical solutions in matrix models, it was not clear whether it is possible to realize the k =/= 1 case as the true vacuum. The massive Yang-Mills-Chern-Simons mat

Pierre-Henri Chavanis, Clement Sire

We derive the Virial theorem appropriate to the generalized Smoluchowski-Poisson system describing self-gravitating Brownian particles and bacterial populations (chemotaxis). We extend previous works by considering the case of an unbounded domain and an arbitrary equation of state. We use the Virial theorem to study the diffusion (evaporation) of an isotherm

V. Balagura, M. Danilov, B. Dolgoshein, S. Klemin

The performance of the $200\times2.5\times1$ cm$^3$ plastic scintillator strip with wavelength shifting fiber read-out by two novel photodetectors called Silicon PhotoMultipliers (SiPMs) is discussed. The advantages of SiPM relative to the traditional multichannel photomultiplier are shown. Light yield and light attenuation measurements are presented. This t

D. Porras, F. Verstraete, J. I. Cirac

We present an algorithm for the calculation of eigenstates with definite linear momentum in quantum lattices. Our method is related to the Density Matrix Renormalization Group, and makes use of the distribution of multipartite entanglement to build variational wave--functions with translational symmetry. Its virtues are shown in the study of bilinear--biquad

Dhananjay P. Mehendale

In this paper we develop three characterizations for isomorphism of graphs. The first characterization is obtained by associating certain bitableaux with the graphs. We order these bitableaux by suitably defined lexicographic order and denote the bitableau that is least in this order as the standard representation for the associated graph. The standard repre

Hajime Kawahara, Kohji Yoshikawa, Shin Sasaki, Yasushi Suto

We discuss the detectability of Warm/Hot Intergalactic medium (WHIM) via the absorption lines toward bright point sources with a future X-ray satellite mission, XEUS. While we consider bright QSOs as specific examples, the methodology can be applied to bright GRB afterglows. We create mock absorption spectra for bright QSOs (more than 20 QSOs over the all sk

B. Pire, L. Szymanowski

We study the scaling regime of nucleon - anti-nucleon annihilation into a deeply virtual photon and a meson, bar p N -> gamma* pi. We obtain the leading twist amplitude in the kinematical region where it factorizes into an antiproton distribution amplitude, a short-distance matrix element related to nucleon form factor and the long-distance dominated transit

Henri Nguyen-Thi, Joseph Gastaldi, Thomas Schenk, Guillaume Reinhart

The dynamics of quasicrystal growth remains an unsolved problem in condensed matter. By means of synchrotron live imaging, facetted growth proceeding by the tangential motion of ledges at the solid-melt interface is clearly evidenced all along the solidification of icosahedral AlPdMn quasicrystals. The effect of interface kinetics is significant so that nucl

S. Reid, G. Cagnoli, D. R. M. Crooks, J. Hough

The thermo-mechanical properties of silicon make it of significant interest as a possible material for mirror substrates and suspension elements for future long-baseline gravitational wave detectors. The mechanical dissipation in 92um thick <110> single-crystal silicon cantilevers has been observed over the temperature range 85 K to 300 K, with dissipation a

S. M. Gerasyuta, V. I. Kochkin

The relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained. The five-quark amplitudes for the low-lying pentaquarks including the u, d, s- quarks are calculated. The poles of these a

R. J. Harris, A. Rákos, G. M. Schuetz

We discuss the long-time limit of the integrated current distribution for the one-dimensional zero-range process with open boundaries. We observe that the current fluctuations become site-dependent above some critical current and argue that this is a precursor of the condensation transition which occurs in such models. Our considerations for the totally asym

I. L. Buchbinder, N. G. Pletnev

We develop a systematic approach to construct the one-loop ${\cal N}=4$ SYM effective action depending on both ${\cal N}=2$ vector multiplet and hypermultiplet background fields. Beginning with the formulation of ${\cal N}=4$ SYM theory in terms of ${\cal N}=2$ harmonic superfields, we construct the one-loop effective action using the covariant ${\cal N}=2$

Michal Demetrian

The vacuum decay in a de Sitter universe is studied within semiclassical approximation for the class of effective inflaton potentials whose curvature at the top is close to a critical value. By comparing the actions of the Hawking - Moss instanton and the Coleman - de Luccia instanton(s) the mode of vacuum decay is determined. The case when the fourth deriva

Xin Zhang

In this paper we study the holographic dark energy model proposed by Li from the statefinder viewpoint. We plot the evolutionary trajectories of the model with $c=1$ in the statefinder parameter-planes. The statefinder diagrams characterize the properties of the holographic dark energy and show the discrimination between this scenario and other dark energy m

Ken&#39;ichi Ohshika

We shall show that for a given homeomorphism type and a set of end invariants (including the parabolic locus) with necessary topological conditions which a topologically tame Kleinian group with that homeomorphism type must satisfy, there is an algebraic limit of minimally parabolic, geometrically finite Kleinian groups which has exactly that homeomorphism t

Chong-Xing Yue, Wei Wang, Zheng-Jun Zong, Feng Zhang

In the framework of the littlest Higgs($LH$) model, we consider the processes $e^{+}e^{-}\toν\barνH^{0}$ and $e^{+}e^{-}\to W^{*}W^{*}ν\barν\toν\barνt\bar{t}$, and calculate the contributions of new particles to the cross sections of these processes in the future high energy $e^{+}e^{-}$ collider($ILC$) with $\sqrt{S}=1TeV$. We find that, with reasonable val

Masahiko Yoshioka

In networks of periodically firing spiking neurons that are interconnected with chemical synapses, we analyze cluster state, where an ensemble of neurons are subdivided into a few clusters, in each of which neurons exhibit perfect synchronization. To clarify stability of cluster state, we decompose linear stability of the solution into two types of stabiliti

Y. Kurihara

A set of one-loop vertex and box tensor-integrals with massless internal particles has been obtained directly without any reduction method to scalar-integrals. The results with one or two massive external lines for the vertex integral and zero or one massive external lines for the box integral are shown in this report. Dimensional regularization is employed

Hua-Shu Dou, Boo Cheong Khoo, Her Mann Tsai

Axial flow in an annulus between two concentric cylinders is commonly seen in various flow devices used in chemical processing industries and petroleum science and engineering. The flow state in the annulus strongly influences the performance of fluid transportation in the devices. Therefore, the determination of flow state which is laminar flow or turbulent

Pradip Roy, Abhee K. Dutt-Mazumder, Jan-e Alam

Charmonium productions in $p-p$ and $A-B$ collisions have been estimated within the ambit of colour evaporation model (CEM). The model parameters have been fixed by fitting the theoretical results with CDF data. The method is then applied to RHIC and LHC energies to obtain the transverse momentum distributions of $J/ψ$, $ψ^{\prime}$ and $χ_c$. Suppression du

S. Dong, K. F. Wang, Han Zhu, X. Y. Yao

Current theoretical approaches to manganites mainly stem from magnetic framework, in which the electronic transport is thought to be spin-dependent and the double exchange mechanism plays a core role. However, quite a number of experimental observations can yet not be reasonably explained. For example, multiplicate insulator-metal transitions and resistivity

Xin Liu, Shuang Nan Zhang

We perform multi-scale non-Gaussianity detection and localization to the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data in both wavelet and real spaces. Such an analysis is facilitated by spherical wavelet transform and inverse transform techniques developed by the YAWtb team. Skewness and kurtosis as test statistics are calculated on scales fro

Masahito Hayashi, Keiji Matsumoto, Yoshiyuki Tsuda

We study how well answer to the question ``Is the given quantum state equal to a certain maximally entangled state?&#39;&#39; using LOCC, in the context of hypothesis testing. Under several locality and invariance conditions, optimal tests will be derived for several special cases by using basic theory of group representations. Some optimal tests are realize

Marek Chrobak, Claire Kenyon, John Noga, Neal E. Young

In the k-median problem we are given sets of facilities and customers, and distances between them. For a given set F of facilities, the cost of serving a customer u is the minimum distance between u and a facility in F. The goal is to find a set F of k facilities that minimizes the sum, over all customers, of their service costs. Following Mettu and Plaxton,

Mario Leandro Aolita, Marcos Saraceno

In this work we study several models of decoherence and how different quantum maps and algorithms react when perturbed by them. Following closely Ref. [1], generalizations of the three paradigmatic one single qubit quantum channels (these are the depolarizing channel, the phase damping channel and the amplitude damping channel) for the case of an arbitrarily

Arturo Argüelles, Thomas Dittrich

We construct, using simple geometrical arguments, a Wigner function defined on a discrete phase space of arbitrary integer Hilbert-space dimension that is free of redundancies. ``Ghost images&#39;&#39; plaguing other Wigner functions for discrete phase spaces are thus revealed as artifacts. It allows to devise a corresponding phase-space propagator in an una

Hoi-Kwong Lo, John Preskill

Ideal quantum key distribution (QKD) protocols call for a source that emits single photon signals, but the sources used in typical practical realizations emit weak coherent states instead. A weak coherent state may contain more than one photon, which poses a potential security risk. QKD with weak coherent state signals has nevertheless been proven to be secu

Sergey Bravyi, David Fattal, Daniel Gottesman

Let $|Ψ>$ be an arbitrary stabilizer state distributed between three remote parties, such that each party holds several qubits. Let $S$ be a stabilizer group of $|Ψ>$. We show that $|Ψ>$ can be converted by local unitaries into a collection of singlets, GHZ states, and local one-qubit states. The numbers of singlets and GHZs are determined by dimensions of c

G Gordon Worley

In 2003, Bechmann-Pasquinucci introduced the concept of quantum seals, a quantum analogue to wax seals used to close letters and envelopes. Since then, some improvements on the method have been found. We first review the current quantum sealing techniques, then introduce and discuss potential applications of quantum message sealing, and conclude with some di

Boris Ivlev

Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. A periodic structure of the wave function is formed in the direction joining the wells. The resulting motion can be coherent lik

Angelo C. M. Carollo, Vlatko Vedral

In this brief review we describe the idea of holonomic quantum computation. The idea of geometric phase and holonomy is introduced in a general way and we provide few examples that should help the reader understand the issues involved.

A. S. Holevo, M. E. Shirokov, R. F. Werner

In this paper we give a general integral representation for separable states in the tensor product of infinite dimensional Hilbert spaces and provide the first example of separable states that are not countably decomposable. We also prove the structure theorem for the quantum communication channels that are entanglement-breaking, generalizing the finite-dime

Chikako Uchiyama, Masaki Aihara

We show that the multipulse application can suppress the degradation of the quantum entanglement with focusing on the concurrence, the degree of entanglement. By evaluating the time evolution of concurrence with a linearly interacting spin-boson model under pulse application, we find that the effectiveness of the multipulse control depends on the non-Markovi

Romulus Breban, Sally Blower

Pilot studies of structured treatment interruptions (STI) in HIV therapy have shown that patients can maintain low viral loads whilst benefiting from reduced treatment toxicity. However, a recent STI clinical trial reported a high degree of virologic failure. Here we present a novel hypothesis that could explain virologic failure to STI and provides new insi

Norbert Straumann

Einstein&#39;s thesis ``A New Determination of Molecular Dimensions&#39;&#39; was the second of his five celebrated papers in 1905. Although it is -- thanks to its widespread practical applications -- the most quoted of his papers, it is less known than the other four. The main aim of the talk is to show what exactly Einstein did in his dissertation. As an i

J. F. Kenney, Richard J. Petti

A general equation of state for the hard-body reference system of real fluid has been developed from first principles, statistical mechanical arguments using metric differential geometry to describe the &#34;available volume,&#34; V0, and its determining surface, S0, of a hard-body fluid. The rigorous, exact results of scaled particle theory of Reiss et al.,

Bernhard Rothenstein, Ioan Damian

Invariance of the counted number of photons and the Lorentz-Einstein transformations enable us to derive transformation equations for the physical quantities introduced in order to characterize energy emission and transport in a plane and in a spherical electromagnetic wave propagating in vacuum.

Sitabhra Sinha, Raj Kumar Pan

The distribution of gross earnings of movies released each year show a distribution having a power-law tail with Pareto exponent $α\simeq 2$. While this offers interesting parallels with income distributions of individuals, it is also clear that it cannot be explained by simple asset exchange models, as movies do not interact with each other directly. In fac

Sitabhra Sinha

It is known that asset exchange models with symmetric interaction between agents show either a Gibbs/log-normal distribution of assets among the agents or condensation of the entire wealth in the hands of a single agent, depending upon the rules of exchange. Here we explore the effects of introducing asymmetry in the interaction between agents with different

M. A. F. Gomes, G. L. Vasconcelos, I. J. Tsang, I. R. Tsang

The distribution of living languages is investigated and scaling relations are found for the diversity of languages as a function of the country area and population. These results are compared with data from Ecology and from computer simulations of fragmentation dynamics where similar scalings appear. The language size distribution is also studied and shown

S. Escoffier, P. Y. Bertin, M. Brossard, E. Burtin

A major advance in accurate electron beam polarization measurement has been achieved at Jlab Hall A with a Compton polarimeter based on a Fabry-Perot cavity photon beam amplifier. At an electron energy of 4.6 GeV and a beam current of 40 uA, a total relative uncertainty of 1.5% is typically achieved within 40 min of data taking. Under the same conditions mon

B. Tsipinyuk, A. Bekkerman, E. Kolodney

A one parameter expression for the single ionization cross-section of atoms by electron impact is presented. Using this expression, the agreement obtained with available experimental data for 45 elements (from ionization threshold up to 200 eV ionizing electron energy) is shown to be comparable with (or better than) that achieved using other multi-parameter

R. V. Korkin

The $P$ and $T$ odd deuteron multipoles are calculated in the Reid nucleon-nucleon potential in the chiral limit $m_π\to 0$. The contact current generated by the $π$-meson exchange does not contribute to the anapole moment. The contact current generated by the vector meson exchange is negligible in comparison with other contributions of vector mesons. The re

Sergei P. Maydanyuk

In paper SUSY-hierarchies of one-dimensional potentials with continuous energy spectra are studied. Use of such hierarchies for analysis of reflectionless potentials is substantiated from the physical point of view. An interdependence (based on Darboux transformations) between spectral characteristics of potentials-partners is determined, an uniqueness of it

S. Typel

The Lagrangian density of standard relativistic mean-field (RMF) models with density-dependent meson-nucleon coupling vertices is modified by introducing couplings of the meson fields to derivative nucleon densities. As a consequence, the nucleon self energies, that describe the effective in-medium interaction, become momentum dependent. In this approach it

G. Ya. Korenman, V. P. Popov, V. N. Pomerantsev

The Coulomb deexcitation of light exotic atoms in collisions with hydrogen atoms has been studied in the framework of the fully quantum-mechanical close-coupling method for the first time. The calculations of the $l$-averaged cross sections have been performed for $(μp)_n$ and $(μd)_n$ atoms in the states with the principal quantum number $n=3 ÷8$ and relati

Santiago Madruga, Hermann Riecke, Werner Pesch

While non-Boussinesq hexagonal convection patterns are well known to be stable close to threshold (i.e. for Rayleigh numbers $R \approx R_c$), it has often been assumed that they are always unstable to rolls already for slightly higher Rayleigh numbers. Using the {\em incompressible} Navier-Stokes equations for parameters corresponding to water as a working

M. Aslam Chaudhry, Amer Iqbal, Asghar Qadir

The Fermi-Dirac and Bose-Einstein particles satisfy corresponding statistical distributions. In the phenomena of charge fractionalization and the fractional quantum Hall effect it is found that particles behave as if they are neither fermions nor bosons. Such particles are called anyons. The integral functions for bosons and fermions are available in the lit

Nicolae Cotfas

Many of the mathematical models used in quasicrystal physics are based on tilings of the plane or space obtained by using strip projection method in a superspace of dimension four, five or six. We present some mathematical results which allow one to use this very elegant method in spaces of dimension much higher and to generate directly quasiperiodic packing

Benjamin Schlein

We report on some recent results regarding the dynamical behavior of a trapped Bose-Einstein condensate, in the limit of a large number of particles. These results were obtained in \cite{ESY}, a joint work with L. Erd\H os and H.-T. Yau.

Alexander Soshnikov

The paper studies the spectral properties of large Wigner, band and sample covariance random matrices with heavy tails of the marginal distributions of matrix entries.