November 2007 arXiv papers — page 19

Reizaburo Kitai, Hiroko Watanabe, Tahei Nakamura, Ken-ichi Otsuji

High resolution imaging observation of a sunspot umbra was done with Hinode Solar Optical Telescope (SOT). Filtergrams in wavelengths of blue and green continuum were taken during three consecutive days. The umbra consisted of a dark core region, several diffuse components and numerous umbral dots. We derived basic properties of umbral dots (UDs), especially

Muhammad Akashi, Yohai Meiron, Noam Soker

We conduct 2D numerical simulations of jets expanding into the slow wind of asymptotic giant branch stars. We show that the post-shock jets' material can explain the observed extended X-ray emission from some planetary nebulae (PNs). Such jets are thought to shape many PNs, and therefore it is expected that this process will contribute to the X-ray emiss

Joseph S. Kong, Vwani P. Roychowdhury

There has been a rich interplay in recent years between (i) empirical investigations of real world dynamic networks, (ii) analytical modeling of the microscopic mechanisms that drive the emergence of such networks, and (iii) harnessing of these mechanisms to either manipulate existing networks, or engineer new networks for specific tasks. We continue in this

Gestur Olafsson, Shijun Zheng

In this article we give an overview on some recent development of Littlewood-Paley theory for Schrödinger operators. We extend the Littlewood-Paley theory for special potentials considered in the authors' previous work. We elaborate our approach by considering potential in $C^\infty_0$ or Schwartz class in one dimension. In particular the low energy esti

M. Kawamura, H. Takahashi, S. Masubuchi, Y. Hashimoto

Nuclear spins are polarized electrically in a breakdown regime of an odd-integer quantum Hall effect (QHE). Electron excitation to the upper Landau subband with the opposite spin polarity flips nuclear spins through the hyperfine interaction. The polarized nuclear spins reduce the spin-splitting energy and accelerate the QHE breakdown. The Knight shift of th

Kenichi Ito, Shu Nakamura

In this paper we study microlocal singularities of solutions to Schrodinger equations on scattering manifolds, i.e., noncompact Riemannian manifolds with asymptotically conic ends. We characterize the wave front set of the solutions in terms of the initial condition and the classical scattering maps under the nontrapping condition. Our result is closely rela

Niranjay Ravindran, Nihar Jindal

Block diagonalization is a linear precoding technique for the multiple antenna broadcast (downlink) channel that involves transmission of multiple data streams to each receiver such that no multi-user interference is experienced at any of the receivers. This low-complexity scheme operates only a few dB away from capacity but requires very accurate channel kn

Venkata Seshu Kumar Kurapati

We propose a fully dynamic algorithm for maintaining reachability information in directed graphs. The proposed deterministic dynamic algorithm has an update time of $O((ins*n^{2}) + (del * (m+n*log(n))))$ where $m$ is the current number of edges, $n$ is the number of vertices in the graph, $ins$ is the number of edge insertions and $del$ is the number of edg

H. Ingerslev Jørgensen, K. Grove-Rasmussen, K. -Y. Wang, A. M. Blackburn

An artifcial two-atomic molecule, also called a double quantum dot (DQD), is an ideal system for exploring few electron physics. Spin-entanglement between just two electrons can be explored in such systems where singlet and triplet states are accessible. These two spin-states can be regarded as the two states in a quantum two-state system, a so-called single

Sangtaek Kim, Robert R. Mcleod, Mark Saffman, Kelvin H. Wagner

We demonstrate a dual wavelength acousto-optic deflector (AOD) designed to deflect two wavelengths to the same angles by driving with two RF frequencies. The AOD is designed as a beam scanner to address two-photon transitions in a two-dimensional array of trapped neutral Rb atoms in a quantum computer. Momentum space is used to design AODs that have the same

Xiao Zhang

We extend our previous definition of quasi-local mass to 2-spheres whose Gauss curvature is negative and prove its positivity.

Frank Nielsen, Richard Nock

In this paper, we generalize the notions of centroids and barycenters to the broad class of information-theoretic distortion measures called Bregman divergences. Bregman divergences are versatile, and unify quadratic geometric distances with various statistical entropic measures. Because Bregman divergences are typically asymmetric, we consider both the left

Hossein Yavartanoo, Sangheon Yun

We investigate the attractor mechanism in Kaluza-Klein black hole solution in the presence of higher derivative terms. In particular, we discuss the attractor behavior of static black holes by using the effective potential approach as well as entropy function formalism. We consider different higher derivative terms with a general coupling to moduli field. Fo

T. Aste, T. Di Matteo

We introduce a deductive statistical mechanics approach for granular materials which is formally built from few realistic physical assumptions. The main finding is an universal behavior for the distribution of the density fluctuations. Such a distribution is the equivalent of the Maxwell-Boltzmann's distribution in the kinetic theory of gasses. The compa

J. P. D'Incao, B. D. Esry

We study inelastic processes for ultracold three-body systems in which only one interaction is resonant. We have found that the decay rates for weakly bound molecules due to collisions with other atoms can be suppressed not only without fermionic statistics but also when bosonic statistics applies. In addition, we show that at ultracold temperatures three-bo

George Hau, Richard Bower, Virginia Kilborn, Duncan Forbes

A common feature of hierarchical galaxy formation models is the process of "inverse" morphological transformation: a bulge dominated galaxy accretes a gas disk, dramatically reducing the system's bulge-to-disk mass ratio. During their formation, present day galaxies may execute many such cycles across the Hubble diagram. A good candidate for such

Filipe Moura

We review our recent work on the existence of a new independent R^4 term, at one loop, in the type IIA and heterotic effective actions, after reduction to four dimensions, besides the usual square of the Bel-Robinson tensor. We discuss its supersymmetrization.

Mark Kaminskiy, Vasiliy Krivtsov

This paper introduces a simple index that helps to assess the degree of aging or rejuvenation of a (non)repairable system. The index ranges from -1 to 1 and is negative for the class of decreasing failure rate distributions (or deteriorating point processes) and is positive for the increasing failure rate distributions (or improving point processes). The int

Yutaka Fujita

We study the influence of a strong AGN outburst on the surrounding galaxies. The AGN is assumed to reside in a group of galaxies, and an outburst excites a shock wave in the hot gas in the group. We calculate the impact of the shock wave on the galaxies. We find that if the energy of the outburst is extremely large (E_AGN ~6x10^61 erg) as the one recently ob

M. Y. Mo

In this paper we studied the double scaling limit of a random unitary matrix ensemble near a singular point where a new cut is emerging from the support of the equilibrium measure. We obtained the asymptotic of the correlation kernel by using the Riemann-Hilbert approach. We have shown that the kernel near the critical point is given by the correlation kerne

Paul Kabaila, Khageswor Giri

We consider a linear regression model with regression parameter beta=(beta_1,...,beta_p) and independent and identically N(0,sigma^2) distributed errors. Suppose that the parameter of interest is theta = a^T beta where a is a specified vector. Define the parameter tau=c^T beta-t where the vector c and the number t are specified and a and c are linearly indep

Rafael de la Llave, Alistair Windsor

The celebrated Livsic theorem states that given M a manifold, a Lie group G, a transitive Anosov diffeomorphism f on M and a Holder function η: M \mapsto G whose range is sufficiently close to the identity, it is sufficient for the existence of ϕ:M \mapsto G satisfying η(x) = ϕ(f(x)) ϕ(x)^{-1} that a condition -- obviously necessary -- on the cocycle generat

Ioannis Rousochatzakis, Andreas M. Laeuchli, Frederic Mila

We present a detailed study of the low-energy excitations of two existing finite-size realizations of the planar kagome Heisenberg antiferromagnet on the sphere, the cuboctahedron and the icosidodecahedron. After highlighting a number of special spectral features (such as the presence of low-lying singlets below the first triplet and the existence of localiz

Nadav Drukker, Simone Giombi, Riccardo Ricci, Diego Trancanelli

This paper studies in great detail a family of supersymmetric Wilson loop operators in N=4 supersymmetric Yang-Mills theory we have recently found. For a generic curve on an S^3 in space-time the loops preserve two supercharges but we will also study special cases which preserve 4, 8 and 16 supercharges. For certain loops we find the string theory dual expli

Mark Pollicott, Howard Weiss, Scott A. Wolpert

We prove topological transitivity for the Weil Petersson geodesic flow for two-dimensional moduli spaces of hyperbolic structures. Our proof follows a new approach that exploits the density of singular unit tangent vectors, the geometry of cusps and convexity properties of negative curvature. We also show that the Weil Petersson geodesic flow has: horseshoes

Stephen Doty, Kathryn Nyman

Permutation modules are fundamental in the representation theory of symmetric groups $\Sym_n$ and their corresponding Iwahori--Hecke algebras $\He = \He(\Sym_n)$. We find an explicit combinatorial basis for the annihilator of a permutation module in the "integral" case -- showing that it is a cell ideal in G.E. Murphy's cell structure of $\He$. T

D0 Collaboration, V. M Abazov

We report a search for R-parity violating production and decay of sneutrino particles in the e+mu final state with 1.04+-0.06 fb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider in 2002--2006. Good agreement between the data and the standard model prediction is observed. With no evidence for new physics, we set limits on the R-parit

Yangsen Yao, Michael A. Nowak, Q. Daniel Wang, Norbert S. Schulz

Although the existence of large-scale hot gaseous halos around massive disk galaxies have been theorized for a long time, there is yet very little observational evidence. We report the Chandra and XMM-Newton grating spectral detection of OVII and NeIX Kalpha absorption lines along the sight-line of 4U 1957+11. The line absorption is consistent with the inter

Radovan Dermisek, Herman Verlinde, Lian-Tao Wang

We show that, in string models with the MSSM residing on D-branes, the bino mass can be generated in a geometrically separated hidden sector. Hypercharge mediation thus naturally teams up with anomaly mediation. The mixed scenario predicts a distinctive yet viable superpartner spectrum, provided that the ratio αbetween the bino and gravitino mass lies in the

Caio H. Lewenkopf, Eduardo R. Mucciolo, Antonio H. Castro Neto

Using the recursive Green's function method, we study the problem of electron transport in a disordered single-layer graphene sheet. The conductivity is of order $e^2/h$ and its dependence on the carrier density has a scaling form that is controlled solely by the disorder strength and the ratio between the sample size and the correlation length of the di

Gerardo Chowell, Hiroshi Nishiura

This article reviews quantitative methods to estimate the basic reproduction number of pandemic influenza, a key threshold quantity to help determine the intensity of interventions required to control the disease. Although it is difficult to assess the transmission potential of a probable future pandemic, historical epidemiologic data is readily available fr

L. DiCarlo, J. R. Williams, Yiming Zhang, D. T. McClure

We report measurements of current noise in single- and multi-layer graphene devices. In four single-layer devices, including a p-n junction, the Fano factor remains constant to within +/-10% upon varying carrier type and density, and averages between 0.35 and 0.38. The Fano factor in a multi-layer device is found to decrease from a maximal value of 0.33 at t

Caleb K. Lo, Sriram Vishwanath, Robert W. Heath

This paper considers the problem of selecting a subset of nodes in a two-hop wireless network to act as relays in aiding the communication between the source-destination pair. Optimal relay subset selection with the objective of maximizing the overall throughput is a difficult problem that depends on multiple factors including node locations, queue lengths a

Parsa Bonderson, J. K. Slingerland

We generalize the fractional quantum Hall hierarchy picture to apply to arbitrary, possibly non-Abelian, fractional quantum Hall states. Applying this to the nu = 5/2 Moore-Read state, we construct new explicit trial wavefunctions to describe the fractional quantum Hall effect in the second Landau level. The resulting hierarchy of states, which reproduces th

Christian Buth, Robin Santra

We devise a theory of x-ray absorption by symmetric-top molecules which are aligned by an intense optical laser. Initially, the density matrix of the system is composed of the electronic ground state of the molecules and a thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion of the two-color (laser plus x rays) rotational-electronic

Luciano da F. Costa, Osvaldo N. Oliveira, Gonzalo Travieso, Francisco A. Rodrigues

The success of new scientific areas can be assessed by their potential for contributing to new theoretical approaches and in applications to real-world problems. Complex networks have fared extremely well in both of these aspects, with their sound theoretical basis developed over the years and with a variety of applications. In this survey, we analyze the ap

T. D. Andersen, C. C. Lim

Negative specific heat is a dramatic phenomenon where processes decrease in temperature when adding energy. It has been observed in gravo-thermal collapse of globular clusters. We now report finding this phenomenon in bundles of nearly parallel, periodic, single-sign generalized vortex filaments in the electron magnetohydrodynamic (EMH) model for the unbound

Andrew Noble, Maxim Perelstein

We argue that, within a broad class of extensions of the Standard Model, there is a tight corellation between the dynamics of the electroweak phase transition and the cubic self-coupling of the Higgs boson: Models which exhibit a strong first-order EWPT predict a large deviation of the Higgs self-coupling from the Standard Model prediction, as long as no acc

Shaouly Bar-Shalom, Arvind Rajaraman

We consider models of maximal flavor violation (MxFV), in which a new scalar mediates large q_3 <-> q_1 or q_3 <-> q_2 flavor changing transitions (q_i is an i&#39;th generation quark), while q_3 <-> q_3 transitions are suppressed, e.g., ξ_{31}, ξ_{13} ~ V_{tb} and ξ_{33} ~ V_{td}, where ξ_{ij} are the new scalar couplings to quarks and V is the CKM matrix.

Tommy Anderberg

Cruz et al. recently showed that the CMB cold spot can be explained by a GUT-scale texture. But following Turok&#39;s argument that gauged configurations always relax quickly, they posit a global symmetry, without obvious relation to GUTs. An observation by Nambu invalidates Turok&#39;s argument when the broken symmetry group has commuting generators. This i

Andrei V. Afanasev

Recent theoretical developments in the studies of two-photon exchange effects in elastic electron-proton scattering are reviewed. Two-photon exchange mechanism is considered a likely source of discrepancy between polarized and unpolarized experimental measurements of the proton electric form factor at momentum transfers of several GeV$^2$. This mechanism pre

Paul Stokes, Saiful I. Khondaker

We present a simple and scalable technique for the fabrication of solution processed & local gated carbon nanotube field effect transistors (CNT-FETs). The approach is based on directed assembly of individual single wall carbon nanotube from dichloroethane via AC dielectrophoresis (DEP) onto pre-patterned source and drain electrodes with a local aluminum gat

A. D. Speliotopoulos

On the cosmological length scale, recent measurements by WMAP have validated $Λ$CDM to a precision not see before in cosmology. Such is not the case on galactic length scales, however, where the `cuspy-core&#39; problem has demonstrated our lack of understanding of structure formation. Here, we propose a solution to the &#39;cuspy-core&#39; problem based on

Oleg Antipin, David Atwood, Amarjit Soni

The original Randall-Sundrum (RS) model with a warped extra dimension along with extensions provides the possibility for a simultaneous solution to Planck-weak hierarchy problem as well as the flavor puzzle in the Standard Model (SM). The most distinctive feature of this scenario is the existence of Kaluza-Klein (KK) gravitons whose masses and couplings to t

Robert Wagner

Since 2002, the number of detected blazars at gamma-ray energies above 100 GeV has more than doubled. I study 17 blazars currently known to emit E>100 GeV gamma rays. Their intrinsic energy spectra are reconstructed by removing extragalactic background light attenuation effects. Luminosity and spectral slope in the E>100 GeV region are then compared and corr

Steven Diehl, Thomas S. Statler

We report on the discovery of a new quantitative relationship between X-ray gas morphology and radio and X-ray AGN luminosities in normal elliptical galaxies. This is the second paper in a series using data on 54 objects from the Chandra public archive and builds on the findings of Paper I, which demonstrated that hydrostatic equilibrium in elliptical galaxi

S. Mangano

The ANTARES neutrino telescope is presently being built in the Mediterranean Sea at a depth of 2500 m. The primary aim of the experiment is the detection of high energy cosmic muon neutrinos, which are identified by the muons that are produced in charged current interactions. These muons are detected by measuring the Cerenkov light which they emit traversing

A. N. Ivanov, M. Faber, R. Reda, P. Kienle

The nuclear K-shell electron-capture (EC)and positron (beta+) decay constants, lambda_(EC) and lambda_(beta^+) of H-like 140Pr58+ and He-like 140Pr57+ ions, measured recently in the ESR ion storage ring at GSI, were calculated using standard weak interaction theory. The calculated ratios R = lambda_(EC)/lambda_(beta^+) of the decay constants agree with the e

Terry Anderson, John Loftus, Narad Rampersad, Nicolae Santean

Given a language L and a nondeterministic finite automaton M, we consider whether we can determine efficiently (in the size of M) if M accepts at least one word in L, or infinitely many words. Given that M accepts at least one word in L, we consider how long a shortest word can be. The languages L that we examine include the palindromes, the non-palindromes,

M. Bauer, W. Pietsch, G. Trinchieri, D. Breitschwerdt

Aims: We present a study of the diffuse X-ray emission in the halo and the disc of the starburst galaxy NGC 253. Methods: After removing point-like sources, we analysed XMM-Newton images, hardness ratio maps and spectra from several regions in the halo and the disc. We introduce a method to produce vignetting corrected images from the EPIC pn data, and we de

Marina Seikel, Dominik J. Schwarz

We test the present expansion of the universe using supernova type Ia data without making any assumptions about the matter and energy content of the universe or about the parameterization of the deceleration parameter. We assume the cosmological principle to apply in a strict sense. The result strongly depends on the data set, the light-curve fitting method

Jerome Kaminker, Xiang Tang

We study a Hopf algebroid, $\calh$, naturally associated to the groupoid $U_n^δ\ltimes U_n$. We show that classes in the Hopf cyclic cohomology of $\calh$ can be used to define secondary characteristic classes of trivialized flat $U_n$-bundles. For example, there is a cyclic class which corresponds to the universal transgressed Chern character and which give

Edward Anderson

In quantum gravity, one seeks to combine quantum mechanics and general relativity. In attempting to do so, one comes across the `problem of time&#39; impasse: the notion of time is conceptually different in each of these theories. In this seminar, I consider the timeless records approach toward resolving this. Records are localized, information-containing su

M. M. Wolf, J. Eisert, T. S. Cubitt, J. I. Cirac

We investigate what a snapshot of a quantum evolution - a quantum channel reflecting open system dynamics - reveals about the underlying continuous time evolution. Remarkably, from such a snapshot, and without imposing additional assumptions, it can be decided whether or not a channel is consistent with a time (in)dependent Markovian evolution, for which we

F. R. Klinkhamer, G. E. Volovik

A spacetime-independent variable is introduced which characterizes a Lorentz-invariant self-sustained quantum vacuum. For a perfect (Lorentz-invariant) quantum vacuum, the self-tuning of this variable nullifies the effective energy density which enters the low-energy gravitational field equations. The observed small but nonzero value of the cosmological cons

Herman J. Mosquera Cuesta, Carlos A. Bonilla Quintero

Determination of pulsar parallaxes and proper motions addresses fundamental astrophysical open issues. Here, the ATNF Catalog is scrutinized searching for pulsar distances and proper motions. For a sample of 212 run away pulsars (RAPs), which currently run across the Galaxy at very high speed and undergo large displacements, some gravitational-wave (GW) sign

Michele Della Morte

I review recent progresses in heavy quarks physics on the lattice. I focus on decay constants and form factors relevant for the extraction of CKM matrix elements from experimental data. B-\bar{B} mixing is also discussed. In the last part of the paper I describe phenomenological applications of Heavy Quark Effective Theory (HQET) on the lattice, presenting i

A. V. Kisselev, V. A. Petrov

The average charged hadron multiplicity in the $e^+e^-$ events with the primary $t\bar{t}$-pair at the collision energy 500 GeV, as well as the average multiplicity of charged hadrons from the top quark are calculated in QCD to be $86.7 \pm 1.11$ and $41.0 \pm 0.54$, respectively.

Armin Rainer

Let $V$ be a real finite dimensional representation of a compact Lie group $G$. It is well-known that the algebra $\mathbb R[V]^G$ of $G$-invariant polynomials on $V$ is finitely generated, say by $σ_1,...,σ_p$. Schwarz proved that each $G$-invariant $C^\infty$-function $f$ on $V$ has the form $f=F(σ_1,...,σ_p)$ for a $C^\infty$-function $F$ on $\mathbb R^p$

CDF Collaboration, T. Aaltonen

We present a search for the associated production of charginos and neutralinos in p-pbar collisions at 1.96 TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0 fb-1. We look for final states with one high pT electron or muon, and two additional leptons. Our results are consi

Nikos Frantzikinakis, Emmanuel Lesigne, Mate Wierdl

We study recurrence, and multiple recurrence, properties along the $k$-th powers of a given set of integers. We show that the property of recurrence for some given values of $k$ does not give any constraint on the recurrence for the other powers. This is motivated by similar results in number theory concerning additive basis of natural numbers. Moreover, mot

Tobias Koch, Amos Lapidoth

The capacity of discrete-time, non-coherent, multipath fading channels is considered. It is shown that if the delay spread is large in the sense that the variances of the path gains do not decay faster than geometrically, then capacity is bounded in the signal-to-noise ratio.

Michele Maggiore

When a classical black hole is perturbed, its relaxation is governed by a set of quasinormal modes with complex frequencies ω= ω_R+iω_I. We show that this behavior is the same as that of a collection of damped harmonic oscillators whose real frequencies are (ω_R^2+ω_I^2)^{1/2}, rather than simply ω_R. Since, for highly excited modes, ω_I >> ω_R, this observa

Simone De Liberato, Cristiano Ciuti

We present a quantum theoretical analysis of the electroluminescence from an intersubband transition of a quantum well structure embedded in a planar microcavity. By using a cluster factorization method, we have derived a closed set of dynamical equations for the quantum well carrier and cavity photon occupation numbers, the correlation between the cavity fi

Suh-Urk Chung, Jan Friedrich

We have worked out covariant amplitudes for any two-body decay of a resonance with an arbitrary non-zero mass, which involves arbitrary integer spins in the initial and the final states. One key new ingredient for this work is the application of the total intrinsic spin operator $\vec S$ which is given directly in terms of the generators of the Poincaré grou

Fernando Fantino

Let G be a Mathieu simple group, s in G, O_s the conjugacy class of s and ρan irreducible representation of the centralizer of s. We prove that either the Nichols algebra B(O_s,ρ) is infinite-dimensional or the braiding of the Yetter-Drinfeld module M(O_s, ρ) is negative. We also show that if G=M22 or M24, then the group algebra of G is the only (up to isomo

K. Ropotenko

It is shown that instability of stringy matter near the event horizon of a black hole (the spreading effect) can be characterized by the Lyapunov exponents. The Kolmogorov-Sinai entropy is the sum of all the positive Lyapunov exponents and equals to the inverse gravitational radius. Due to a replacement of the configuration space of a string by its phase spa

Koji Nagata

Recently, [arXiv:0810.3134] is accepted and published. We derive an inequality with two settings as tests for the existence of the Bloch sphere in a spin-1/2 system. The probability theory of measurement outcome within the formalism of von Neumann projective measurement violates the inequality. Namely, we have to give up the existence of the Bloch sphere. Or

Francesco Giacosa

The tetraquark assignement for light scalar states below 1 GeV is discussed on the light of strong decays. The next-to-leading order in the large-N expansion for the strong decays is considered. Mixing with quarkonia states above 1 GeV is investigated within a chiral approach and the inclusion of finite-width effects is taken into account.

Ggyoung-Riun Hwang, Kim Siyeon

Neutrino fluxes at telescopes depend on both initial fluxes out of astronomical bursts and flavor mixing during their travel to the earth. However, since the information on the initial composition requires better precision in mixing angles and vice versa, the neutrino detection at telescopes for itself cannot provide solutions to the both problems. Thus, a p

M. Harmer

We consider a two particle system on a star graph with delta-function interaction. A complete description of the eigensolutions with real momenta is given; specifically it is shown that all eigensolutions can be written as integrals in the momentum plane of sums of products of appropriate one particle solutions.

Hisaki Hatanaka, Kwei-Chou Yang

We study the effect of b to s sbar s scalar/pseudoscalar operators in B to K eta(&#39;), phi K^* decays. In the minimal supersymmetric standard model (MSSM), such scalar/pseudoscalar operators can be induced by the penguin diagrams of neutral Higgs bosons. These operators can be Fierz-transformed into tensor operators, and the resultant tensor operators coul

S. V. Mousavi, A. del Campo, I. Lizuain, M. Pons

This article is based on the talk with the same title at the Blaubeuren meeting. First we discuss briefly the importance of time and time keeping, explaining the basic functioning of clocks in general and atomic clocks in particular, which rely on Ramsey interferometry. The usefulness of cold atoms is discussed as well as their limits in Bose-Einstein conden

Andres Santos

The fundamental question addressed in this paper is whether the partial Chapman--Enskog expansion $P_{xy}=-\sum_{k=0}^\infty η_k ({\partial u_x}/{\partial y})^{2k+1}$ of the shear stress converges or not for a gas of inelastic hard spheres. By using a simple kinetic model it is shown that, in contrast to the elastic case, the above series does converge, the

Yuri Kornyushin

Usually microscopic electrostatic field around charged impurity ions is neglected when the ionization energy is concerned. The ionization energy is considered to be equal to that of a lonely impurity atom. Here the energy of the electrostatic field around charged impurity ions in semiconductor is taken into account. It is shown that the energy of this field

I-Ching Yu, Feng-Li Lin, Ching-Yu Huang

We construct general schemes for multi-partite quantum secret sharing using multi-level systems, and find that the consistent conditions for valid measurements can be summarized in two simple algebraic conditions. The scheme using the very high dimensional mutually unbiased bases can in principle achieve perfect security against intercept-resend attack; and

Ll. Bel

Several other factors, besides the intrinsic local geometry, contribute to give a meaning to a space-time model. The simplest example comes from comparing Minkowski&#39;s and Milne&#39;s model, that both have a null Riemann tensor. We add to these two models a third one which describes a time-dependent locally-Minkowskian spherically symmetric space-time on

Klaus Hornberger, Bassano Vacchini

We show how the effective equation of motion for a distinguished quantum particle in an ideal gas environment can be obtained by means of the monitoring approach introduced in [EPL 77, 50007 (2007)]. The resulting Lindblad master equation accounts for the quantum effects of the scattering dynamics in a non-perturbative fashion and it describes decoherence an

Paweł Sieczka, Janusz A. Hołyst

We proposed a model of interacting market agents based on the Ising spin model. The agents can take three actions: &#34;buy,&#34; &#34;sell,&#34; or &#34;stay inactive.&#34; We defined a price evolution in terms of the system magnetization. The model reproduces main stylized facts of real markets such as: fat-tailed distribution of returns and volatility clu

A. del Campo, I. Lizuain, M. Pons, J. G. Muga

We study the transient dynamics that arise during the formation of an atom laser beam in a tight waveguide. During the time evolution the density profile develops a series of wiggles which are related to the diffraction in time phenomenon. The apodization of matter waves, which relies on the use of smooth aperture functions, allows to suppress such oscillati

J. Ginibre, G. Velo

We review the proof of existence and uniqueness of solutions of the Maxwell-Schr&#34;odinger system in a neighborhood of infinity in time, with prescribed asymptotic behaviour defined in terms of asymptotic data, without any restriction on the size of those data. That result is the basic step in the construction of modified wave operators for the Maxwell-Sch

C. B. Lang

Determining the hadron spectrum and hadron properties beyond the ground states is a challenge in lattice QCD. Most of these results have been in the quenched approximation but now we are entering the dynamical era. I review some of the ideas and methods of the lattice approach, concentrating on a few examples and on results obtained for Chirally Improved (CI

Alessandro Micco, Vincenzo Galdi, Filippo Capolino, Alessandro Della Villa

In this paper, we study the radiation from embedded sources in two-dimensional finite-size &#34;photonic-quasicrystal&#34; (PQC) slabs made of dielectric rods arranged according to a 12-fold symmetric aperiodic tiling. The results from our investigation, based on rigorous full-wave simulations, show the possibility of achieving broadside radiation at multipl

Ivan Marin

Let B be the generalized braid group associated to some finite complex reflection group. We define a representation of B of dimension the number of reflections of the corresponding reflection group, which generalizes the Krammer representation of the classical braid groups, and is thus a good candidate in view of proving the linearity of these groups. We dec

Y. Tanaka, Y. Asano, A. A. Golubov

In s-wave superconductors the Cooper pair wave function is isotropic in momentum space. This property may also be expected for Cooper pairs entering a normal metal from a superconductor due to the proximity effect. We show, however, that such a deduction is incorrect and the pairing function in a normal metal is surprisingly anisotropic because of quasiparti

A. Neronov, M. Chernyakova

We show that TeV gamma-ray emission produced via interactions of high-energy particles with anisotropic radiation field of a massive star in binary systems should have a characteristic rotating hollow cone anisotropy pattern. The hollow cone, whose axis is directed away from the massive star, rotates with the period equal to the orbital period of the system.

Masahiro Kawasaki, Kazunori Nakayama, Masato Senami

We derive general constraints on supersymmetric extension of axion models, in particular paying careful attention to the cosmological effects of saxion. It is found that for every mass range of the saxion from keV to TeV, severe constraints on the energy density of the saxion are imposed. Together with constraints from axino we obtain stringent upper bounds

Antoine Gournay

We say a map f:X \to Y is an \epsilon-embedding if it is continuous and the diameter of the fibres is less than \epsilon. This type of maps is used in the notion of Urysohn width (sometimes referred to as Alexandrov width), a_n(X). It is the smallest real number such that there exists an \epsilon-embedding from X to a n-dimensional polyhedron. Surprisingly f

Jie Luo

This paper considers the average complexity of maximum likelihood (ML) decoding of convolutional codes. ML decoding can be modeled as finding the most probable path taken through a Markov graph. Integrated with the Viterbi algorithm (VA), complexity reduction methods such as the sphere decoder often use the sum log likelihood (SLL) of a Markov path as a boun

Chisa Hotta, Frank Pollmann

We study a model of strongly interacting spinless fermions on an anisotropic triangular lattice. At half-filling and the limit of strong repulsive nearest-neighbor interactions, the fermions align in stripes and form an insulating state. When a particle is doped, it either follows a one-dimensional free motion along the stripes or fractionalizes perpendicula

Minxian Zhu

We prove a conjecture stated in a previous paper by the author about the existence of canonical filtrations for a family of vertex operator algebras in rational levels.

H. F. Chau, V. H. Chan, F. K. Chow

Hypothesis Testing Minority Game (HMG) is a variant of the standard Minority Game (MG) that models the inertial behavior of agents in the market. In the earlier study of our group, we find that agents cooperate better in HMG than in the standard MG when strategies are picked from the full strategy space. Here we continue to study the behavior of HMG when str

Greg Ver Steeg, Nicolas C. Menicucci

We show that entanglement can be used to detect spacetime curvature. Quantum fields in the Minkowski vacuum are entangled with respect to local field modes. This entanglement can be swapped to spatially separated quantum systems using standard local couplings. A single, inertial field detector in the exponentially expanding (de Sitter) vacuum responds as if

Xu Cao, Xi-Guo Lee, Qing-Wu Wang

We explore production mechanism and final state interaction in the $pp \to nK^ + Σ^ +$ channel based on the inconsistent experimental data published respectively by COSY-11 and COSY-ANKE. The scattering parameter $a> 0$ for $nΣ^ +$ interaction is favored by large near-threshold cross section within a nonrelativistic parametrization investigation, and a stron

Minxian Zhu

We study the bimodule structure of the quantum function algebra at roots of 1 and prove that it admits an increasing filtration with factors isomorphic to the tensor products of the dual of Weyl modules $V_λ^* \otimes V_{- ω_0 λ}^*$. As an application we compute the 0-th Hochschild cohomology of the function algebra at roots of 1.

B. Andrei Bernevig, F. D. M. Haldane

We present several conjectures on the behavior and clustering properties of Jack polynomials at \emph{negative} parameter $α=-\frac{k+1}{r-1}$, of partitions that violate the $(k,r,N)$ admissibility rule of Feigin \emph{et. al.} [\onlinecite{feigin2002}]. We find that &#34;highest weight&#34; Jack polynomials of specific partitions represent the minimum degr

Yuya Sasai, Naoki Sasakura

Domain wall solitons are the simplest topological objects in field theories. The conventional translational symmetry in a field theory is the generator of a one-parameter family of domain wall solutions, and induces a massless moduli field which propagates along a domain wall. We study similar issues in braided noncommutative field theories possessing Hopf a

Sergio Iguri, Mario Castagnino

After an appropriate restatement of the GNS construction for topological $^*$-algebras we prove that there exists an isomorphism among the set $\cycl(A)$ of weakly continuous strongly cyclic $^*$-representations of a barreled dual-separable $^*$-algebra with unit $A$, the space $\hilb_A(A^*)$ of the Hilbert spaces that are continuously embedded in $A^*$ and

Jill Tysse, Weiqiang Wang

Generalizing the work of Farahat-Higman on symmetric groups, we describe the structures of the even centers Z_n of integral spin symmetric group superalgebras, which lead to universal algebras termed as the spin FH-algebras. A connection between the odd Jucys-Murphy elements and the Catalan numbers is developed and then used to determine the algebra generato

Dieter Drechsel, Thomas Walcher

This review deals with the structure of hadrons, strongly interacting many-body systems consisting of quarks and gluons. These systems have a size of about 1 fm, which shows up in scattering experiments at low momentum transfers $Q$ in the GeV region. At this scale the running coupling constant of Quantum Chromodynamics (QCD), the established theory of the s