September 2006 arXiv papers — page 23

Hui-Yuan Wang, Ting-Gui Wang, Jun-Xian Wang

Recent works showed that the absorbing material in broad absorption line (BAL) quasars is optically thick to major resonant absorption lines. This material may contribute significantly to the polarization in the absorption lines. In this paper, we present a detailed study of the resonant line scattering process using Monte-Carlo method to constrain the optic

T. G. Kaye, S. Vanaverbeke, J. Innis

The successful detection is reported of radial-velocity variations due to orbital motion of the substellar companion of the star tau Bootis, from data obtained with a small aperture (0.4m) telescope and a fibre-fed high-resolution spectrograph. Radial-velocity observations from observing runs in 2000 and 2004 reveal a periodic variation of 3.30 +/-0.02d, whi

Hugo E. Schwarz, Hektor Monteiro, Ryan Peterson

We show that the inclination to the line of sight of bipolar nebulae strongly affects some of their observed properties. We model these objects as having a spherically symmetric Planetary Nebula and a dusty equatorial density enhancement that produces extinction that varies with the viewing angle. Our sample of 29 nebulae taken from the literature shows a cl

Pablo A. Ferrari, Valentin V. Sisko

We consider zero-range processes in ${\mathbb{Z}}^d$ with site dependent jump rates. The rate for a particle jump from site $x$ to $y$ in ${\mathbb{Z}}^d$ is given by $λ_xg(k)p(y-x)$, where $p(\cdot)$ is a probability in ${\mathbb{Z}}^d$, $g(k)$ is a bounded nondecreasing function of the number $k$ of particles in $x$ and $λ=\{λ_x\}$ is a collection of i.i.d

Z. Conesa del Valle

The ALICE capabilities for W and Z detection at LHC are discussed. The contributions to single muon transverse momentum distribution are evaluated. The expected performance of the muon spectrometer for detecting W and Z bosons via their muonic decay is presented. Possible application for the study of in-medium effects in ultrarelativistic heavy ion collision

A. Mandilara, V. M. Akulin

We have identified a class of many body problems with analytic solution beyond the mean-field approximation. This is the case where each body can be considered as an element of an assembly of interacting particles that are translationally frozen multi-level quantum systems and that do not change significantly their initial quantum states during the evolution

R. O'Shaughnessy, V. Kalogera, K. Belczynski

Binary population synthesis calculations and associated predictions, especially event rates, are known to depend on a significant number of input model parameters with different degrees of sensitivity. At the same time, for systems with relatively low formation rates, such simulations are heavily computationally demanding and therefore the needed exploration

Svetoslav Zahariev

To every Hermitian vector bundle with connection over a compact Riemannian manifold $M$ one can associate a corresponding connection Laplacian acting on the sections of the bundle. We define analogous combinatorial metric dependent Laplacians associated to triangulations of $M$ and prove that their spectra converge, as the mesh of the triangulations approach

The BABAR Collaboration, B. Aubert

We report measurements of the decays B+ -> Phi Phi K+ and B0 -> hi Phi K0 using a sample of 231 million BBbar pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The branching fractions are measured to be Br(B+ -> Phi Phi K+) = (7.5 +/- 1.0 stat. +/- 0.7 syst.) * 10^-6 and Br(B0 -> Phi

E. Z. Kuchinskii, I. A. Nekrasov, M. V. Sadovskii

Optical conductivity of the weakly doped two-dimensional repulsive Hubbard model on the square lattice with nearest and next nearest hoppings is calculated within the generalized dynamical-mean field (DMFT+Σ_p) approach which includes correlation length scale ξinto the standard DMFT equations via the momentum dependent self-energy Σ_p, with full account of a

A. E. Montenegro, S. Carneiro

We investigate cosmological solutions of Brans-Dicke theory with both the vacuum energy density and the gravitational constant decaying linearly with the Hubble parameter. A particular class of them, with constant deceleration factor, sheds light on the cosmological constant problems, leading to a presently small vacuum term, and to a constant ratio between

Pascal Naidon, Paul S. Julienne

Motivated by a recent experiment by Zelevinsky et al. [Phys. Rev. Lett. 96, 203201], we present the theory for photoassociation and optical Feshbach resonances of atoms confined in a tight one-dimensional (1D) or two-dimensional (2D) optical lattice. In the case of an alkaline-earth intercombination resonance, the narrow natural width of the line makes it po

Z. G. Wang

In this work, we study the four form-factors $f_1(Q^2)$, $f_2(Q^2)$, $g_1(Q^2)$ and $g_2(Q^2)$ of the $Σ\to n$ in the framework of the light-cone QCD sum rules approach up to twist-6 three valence quark light-cone distribution amplitudes. The $f_1(0)$ is the basic input parameter in extracting the CKM matrix element $|V_{us}|$ from the hyperon decays. The fo

Jun-Qing Xia, Gong-Bo Zhao, Xinmin Zhang

We investigate the correlation between the neutrino mass limit and dark energy with time evolving equation of state. Parameterizing dark energy as w=w_0+w_1*z/(1+z), we make a global fit using Markov Chain Monte Carlo technique to determine w_0, w_1, neutrino mass as well as other cosmological parameters simultaneously. We pay particular attention to the cor

A. Piccolroaz, G. Mishuris, A. Movchan

The paper addresses the problem of a a semi-infinite plane crack along the interface between two 3D isotropic half-spaces. Two methods of solution have been considered in the past: Lazarus and Leblond (1998) applied the "special" method by Bueckner (1987) and found the expression of the variation of the stress intensity factors for a wavy crack witho

Constantino Tsallis, Andrea Rapisarda, Alessandro Pluchino, Ernesto P. Borges

We discuss the non-Boltzmannian nature of quasi-stationary states in the Hamiltonian Mean Field (HMF) model, a paradigmatic model for long-range interacting classical many-body systems. We present a theorem excluding the Boltzmann-Gibbs exponential weight in Gibbs $Γ$-space of microscopic configurations, and comment a paper recently published by Baldovin and

Rajan Murgan

We review recent results on the Bethe Ansatz solutions for the eigenvalues of the transfer matrix of an integrable open XXZ quantum spin chain using functional relations which the transfer matrix obeys at roots of unity. First, we consider a case where at most two of the boundary parameters {{$\alpha_-$,$\alpha_+$,$\beta_-$,$\beta_+$}} are nonzero. A general

Dinakar Ramakrishnan

Irreducible representations are the building blocks of general, semisimple Galois representations ρ, and cuspidal representations are the building blocks of automorphic forms πof the general linear group. It is expected that when an object of the former type is associated to one of the latter type, usually in terms of an identity of L-functions, the irreduci

David Cimasoni

Bing doubling is an operation which produces a 2-component boundary link B(K) from a knot K. If K is slice, then B(K) is easily seen to be boundary slice. In this paper, we investigate whether the converse holds. Our main result is that if B(K) is boundary slice, then K is algebraically slice. We also show that the Rasmussen invariant can tell that certain B

Ikai Lo, M. H. Gau, J. K. Tsai, Y. L. Chen

We have confirmed the k-dependent spin splitting in wurtzite AlxGa1-xN/GaN heterostructures. Anomalous beating pattern in Shubnikov-de Haas measurements arises from the interference of Rashba and Dresselhaus spin-orbit interactions. The dominant mechanism for the k-dependent spin splitting at high values of k is attributed to Dresselhaus term which is enhanc

Marshall M. Joffe, Dylan Small, Chi-Yuan Hsu

It has recently become popular to define treatment effects for subsets of the target population characterized by variables not observable at the time a treatment decision is made. Characterizing and estimating such treatment effects is tricky; the most popular but naive approach inappropriately adjusts for variables affected by treatment and so is biased. We

Robert Alicki

The recent experimental evidence for entangled states of two Josephson junction qubits is briefly discussed. It is argued that the interpretation of the experimental data strongly depends on the assumed theoretical model. Namely, the qubit states are supposed to be the lowest lying eigenstates of a certain effective Hamiltonian and hence automatically orthog

Rodrigo Medina

We present a simple example in which the importance of the inertial effects of stress is evident. The system is an insulating solid narrow disc whose faces are uniformly charged with charges of equal magnitude and opposite signs. The motion of the system in two different directions is considered. It is shown how the contributions to energy and momentum of th

Takahisa Harayama, Satoshi Sunada, Tomohiro Miyasaka

It is shown that, even when the eigenmodes of an optical cavity are wave-chaotic, the frequency splitting due to the rotation of the cavity occurs and the frequency difference is proportional to the angular velocity although the splitting eigenmodes are still wave-chaotic and do not correspond to any unidirectionally-rotating waves.

A. Figotin, I. Vitebskiy

Wave propagation in spatially periodic media, such as photonic crystals, can be qualitatively different from any uniform substance. The differences are particularly pronounced when the electromagnetic wavelength is comparable to the primitive translation of the periodic structure. In such a case, the periodic medium cannot be assigned any meaningful refracti

Y. Aritomo

The possibility of synthesizing a doubly magic superheavy nucleus, $^{298}114_{184}$, is investigated on the basis of fluctuation-dissipation dynamics. In order to synthesize this nucleus, we must generate more neutron-rich compound nuclei because of the neutron emissions from excited compound nuclei. The compound nucleus $^{304}114$ has two advantages to ac

S. Damjanovic

The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size close to 400K events and the good mass resolution of about 2% made it possible to isolate the excess by subtraction of the decay sources. The s

D. Kepa, Y. Kozitsky

Gibbs states of an infinite system of interacting quantum particles are considered. Each particle moves on a compact Riemannian manifold and is attached to a vertex of a graph (one particle per vertex). Two kinds of graphs are studied: (a) a general graph with locally finite degree; (b) a graph with globally bounded degree. In case (a), the uniqueness of Gib

Y. Kozitsky, T. Pasurek

A rigorous description of the equilibrium thermodynamic properties of an infinite system of interacting $ν$-dimensional quantum anharmonic oscillators is given. The oscillators are indexed by the elements of a countable set $\mathbb{L}\subset \mathbb{R}^d$, possibly irregular; the anharmonic potentials vary from site to site. The description is based on the

Dinakar Ramakrishnan, Freydoon Shahidi

The object of this article is to construct certain classes of arithmetically significant, holomorphic Siegel cusp forms F of genus 2, which are neither of Saito-Kurokawa type, in which case the degree 4 spinor L-function L(s, F) is divisible by an abelian L-function, nor of Yoshida type, in which case L(s,F) is a product of L-series of a pair of elliptic cus

Alexander G. Tartakovsky

In 1960s Shiryaev developed Bayesian theory of change detection in independent and identically distributed (i.i.d.) sequences. In Shiryaev's classical setting the goal is to minimize an average detection delay under the constraint imposed on the average probability of false alarm. Recently, Tartakovsky and Veeravalli (2005) developed a general Bayesian a

Joan E. Licata

In this paper we use Heegaard Floer link homology to determine the dual Thurston polytope for pretzel links of the form P(-2r_1-1, 2q_1, -2q_2, 2r_2+1) where r_i and q_i are positive integers. We apply this result to determine the Thurston norms of spanning surfaces for the individual link components, and we explicitly construct norm-realizing examples of su

Pete L. Clark

Given an algebraic curve C/Q having points everywhere locally and endowed with a suitable involution, we show that there exists a positive density family of prime quadratic twists of C violating the Hasse principle. The result applies in particular to w_N-Atkin-Lehner twists of most modular curves X_0(N) and to w_p-Atkin-Lehner twists of certain Shimura curv

Nina Lebedeva

We give estimates on asymptotic dimensions of products of general hyperbolic spaces with following applications to the hyperbolic groups. We give examples of strict inequality in the product theorem for the asymptotic dimension in the class of the hyperbolic groups; and examples of strict inequality in the product theorem for the hyperbolic dimension. We pro

Dongseok Kim, Jin Hwan Kim, Jaeun Lee, Dianjun Wang

We characterize the equivalence and the weak equivalence of Cayley graphs for a finite group $\C{A}$. Using these characterizations, we find enumeration formulae of the equivalence classes and weak equivalence classes of Cayley graphs. As an application, we find the number of weak equivalence classes of circulant graphs.

Frederic Dambreville

The cross-entropy method (CE) developed by R. Rubinstein is an elegant practical principle for simulating rare events. The method approximates the probability of the rare event by means of a family of probabilistic models. The method has been extended to optimization, by considering an optimal event as a rare event. CE works rather good when dealing with det

Dinakar Ramakrishnan

This article surveys some recent work of the author on Hilbert modular fourfolds X. After some preliminaries on the cohomology and special, codimension 2 cycles Z on X of Hirzebruch-Zagier type, a proof of the Tate conjecture for X over abelian fields is exposed. It is followed by a description of a method to construct classes in the Bloch's Chow group C

Dinakar Ramakrishnan, Jonathan Rogawski

First we reprove, using representation theory and the relative trace formula of Jacquet, an average value result of Duke for modular L-series at the critical center. We also establish a refinement. To be precise, the L-value which appears is L(1/2, f)L(1/2,f,χ) (divided by the Petersson norm of f), and the average is over newforms f of prime level N and coef

Santiago Cambronero, Jose Ramirez, Brian Rider

Consider the Hill's operator $Q = - d^2/dx^2 + q(x)$ in which $q(x)$, $0 \le x \le 1$, is a White Noise. Denote by $f(μ)$ the probability density function of $-λ_0(q)$, the negative of the ground state eigenvalue, at $μ$. We describe the detailed asymptotics of this density as $μ\to +\infty$. This result is based on a precise Laplace analysis of a functi

Yoshinobu Habara

In the preceding paper [arXiv:hep-th/0604217], we construct the Dirac operator and the integral on the canonical noncommutative space. As a matter of fact, they are ones on the noncommutative torus. In the present article, we introduce the method to extend to the Minkowskian and Euclidean cases. As a concluding remark, we present a geometrical notion of our

Laura Mersini-Houghton

Progress in string theory has resulted in a whole landscape of vacua solutions.In this talk I describe a proposal for exploring the cosmological implications of the landscape, based on the dynamics of the wavefunction of the universe propagating on it. The landscape is taken as the phase space of the initial conditions since every of its vacua can potentiall

Ivan Vitev

We review recent theoretical developments in understanding the many-body perturbative QCD dynamics of strongly-interacting hard probes in dense nuclear matter. The relation between initial- and final-state parton scattering in nuclei and the quark-gluon plasma and experimental measurements of the Cronin effect, nuclear shadowing, jet quenching, modified di-h

C. G. Boehmer, T. Harko

We derive upper and lower limits for the basic physical parameters (mass-radius ratio, anisotropy, redshift and total energy) for arbitrary anisotropic general relativistic matter distributions in the presence of a cosmological constant. The values of these quantities are strongly dependent on the value of the anisotropy parameter (the difference between the

Jon Feldman, Ryan O'Donnell, Rocco A. Servedio

We propose and analyze a new vantage point for the learning of mixtures of Gaussians: namely, the PAC-style model of learning probability distributions introduced by Kearns et al. Here the task is to construct a hypothesis mixture of Gaussians that is statistically indistinguishable from the actual mixture generating the data; specifically, the KL-divergence

P. Emelyanov

In this article, we discuss a flow--sensitive analysis of equality relationships for imperative programs. We describe its semantic domains, general purpose operations over abstract computational states (term evaluation and identification, semantic completion, widening operator, etc.) and semantic transformers corresponding to program constructs. We summarize

Patrick Dehornoy

Conjugacy is not the only possible primitive for designing braid-based protocols. To illustrate this principle, we describe a Fiat--Shamir-style authentication protocol that be can be implemented using any binary operation that satisfies the left self-distributive law. Conjugation is an example of such an operation, but there are other examples, in particula

Xiaofei Huang

Many implementations for decoding LDPC codes are based on the (normalized/offset) min-sum algorithm due to its satisfactory performance and simplicity in operations. Usually, each iteration of the min-sum algorithm contains two scans, the horizontal scan and the vertical scan. This paper presents a single-scan version of the min-sum algorithm to speed up the

Gianluca Giovannetti, Geert Brocks, Jeroen van den Brink

We investigate the changes in the electronic structure of copper phthalocyanine (CuPc) crystals that is caused by intercalation with potassium. This is done by means of {\it ab initio} LSDA and LSDA+U calculations of the electronic structure of these molecular crystals. Pristine CuPc is found to be an insulator with local magnetic moments and a Pc-derived va

Andrea Campera, Giuseppe Iannaccone, Felice Crupi

In this paper we show that through electrical characterization and detailed quantum simulations of the capacitance-voltage and current-voltage characteristics it is possible to extract a series of material parameters of alternative gate dielectrics. We have focused on HfO2 and HfSiXOYNZ gate stacks and have extracted information on the nature of localized st

Kazumi Suematsu

The theory of gelation is tested by the recent experiments in poly(urethane) network. The result supports strongly the physical soundness of the theory.

Niraj K. Singh, K. G. Suresh, A. K. Nigam, S. K. Malik

By virtue of the itinerant electron metamagnetism (IEM), the RCo2 compounds with R=Er, Ho and Dy are found to show first order magnetic transition at their ordering temperatures. The inherent instability of Co sublattice magnetism is responsible for the occurrence of IEM, which leads to interesting magnetic and related properties. The systematic studies of t

Niraj K. Singh, K. G. Suresh, D. S. Rana, A. K. Nigam

We report the magnetic, magnetocaloric and magnetoresistance results obtained in Tb(Ni1-xFex)2 compounds with x=0, 0.025 and 0.05. Fe substitution leads to an increase in the ordering temperature from 36 K for x=0 to 124 K for x=0.05. Contrary to a single sharp MCE peak seen in TbNi2, the MCE peaks of the Fe substituted compounds are quite broad. We attribut

S. L. Miller

Thermodynamic implications of anisotropic gas-surface interactions in a closed molecular flow cavity are examined. Anisotropy at the microscopic scale, such as might be caused by reduced-dimensionality surfaces, is shown to lead to reversibility at the macroscopic scale. The possibility of a self-sustaining nonequilibrium stationary state induced by surface

E. Le Floc'h, C. N. A. Willmer, K. Noeske, N. P. Konidaris

As part of the "All Wavelength Extended Groth Strip International Survey" (AEGIS), we describe the panchromatic characterization of an X-ray luminous active galactic nucleus (AGN) in a merging galaxy at z=1.15. This object is detected at infrared (8mic, 24mic, 70mic, 160mic), submillimeter (850mic) and radio wavelengths, from which we derive a bolome

K. L. Luhman, B. M. Patten, M. Marengo, M. T. Schuster

We report the discovery of T dwarf companions to the nearby stars HN Peg (G0V, 18.4 pc, ~0.3 Gyr) and HD 3651 (K0V, 11.1 pc, ~7 Gyr). During an ongoing survey of 5'x5' fields surrounding stars in the solar neighborhood with IRAC aboard the Spitzer Space Telescope, we identified these companions as candidate T dwarfs based on their mid-IR colors. Usin

Lee Homer, Paula Szkody, Arne Henden, Bing Chen

In the latest in our series of papers on XMM-Newton and ground-based optical follow-up of new candidate magnetic cataclysmic variables (mCVs) found in the Sloan Digital Sky Survey, we report classifications of three systems: SDSS J144659.95+025330.3, SDSS J205017.84-053626.8, and SDSS J210131.26+105251.5. Both the X-ray and optical fluxes of SDSS J1446+02 ar

S. K. Leggett, M. J. Currie, W. P. Varricatt, T. G. Hawarden

JHK photometry in the Mauna Kea Observatory (MKO) near-IR system is presented for 115 stars. Of these, 79 are UKIRT standards and 42 are LCO standards. The average brightness is 11.5 mag, with a range of 10 to 15. The average number of nights each star was observed is 4, and the average of the internal error of the final results is 0.011 mag. These JHK data

H. Saio, C. Cameron, R. Kuschnig, G. A. H. Walker

The Microvariability and Oscillations of stars (MOST) satellite has detected low-amplitude light variations ($Δm\sim$1 mmag) in the Be star $β$ CMi (B8Ve). The observations lasted 41 days and the variations have typical periods $\sim 0.3$ days. We demonstrate that the dominant frequencies are consistent with prograde high-order g-modes of $m=-1$ excited by t

Alexandru Dimca, Stefan Papadima, Alexander I. Suciu

For each integer n\ge 2, we construct an irreducible, smooth, complex projective variety M of dimension n, whose fundamental group has infinitely generated homology in degree n+1 and whose universal cover is a Stein manifold, homotopy equivalent to an infinite bouquet of n-dimensional spheres. This non-finiteness phenomenon is also reflected in the fact that

D. R. Dounas-Frazer, A. M. Hermundstad, L. D. Carr

The N -body problem in a double well requires new features for quantum information processing, macroscopic quantum superposition, and other fundamental studies of quantum many body physics in ultracold atoms. One needs (a) tilt, and (b) to go beyond the single-particle ground state in each well, i.e., to two or more energy levels. For (a), we show that a sma

Pavel Bolokhov, Maxim Pospelov, Michael Romalis

Electric dipole moments (EDMs) of elementary particles and atoms probe violations of T and P symmetries and consequently of CP if CPT is an exact symmetry. We point out that EDMs can also serve as sensitive probes of CPT-odd, CP-even interactions, that are not constrained by any other existing experiments. Analyzing models with spontaneously broken Lorentz i

R. Gamen, E. Gosset, N. Morrell, V. Niemela

Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD93162 (=WR25), this object has been predicted to be a colliding-wind binary system. However, radial-velocity variations that would prove the suspected binary nature have yet to be found. We spectroscopically monitored this object to investigate its possible variabili

Yunfeng Shi, Michael B. Katz, Hui Li, Michael L. Falk

Molecular dynamics simulations of shear band development over 1000% strain in simple shear are used to test whether the local plastic strain rate is proportional to exp(-1/chi), where chi is a dimensionless quantity related to the "disorder temperature" or "free volume" that characterizes the structural state of the glass. Scaling is observed

Ian Sullivan, Asantha Cooray, Ranga-Ram Chary, James J. Bock

We describe the angular power spectrum of resolved sources at 3.6 microns (L-band) in Spitzer imaging data of the GOODS HDF-N, the GOODS CDF-S, and the NDWFS Bootes field in several source magnitude bins. We also measure angular power spectra of resolved sources in the Bootes field at K_S and J-bands using ground-based IR imaging data. In the three bands, J,

Amac Herdagdelen, Eser Aygun, Haluk Bingol

Generalized preferential attachment is defined as the tendency of a vertex to acquire new links in the future with respect to a particular vertex property. Understanding which properties influence link acquisition tendency (LAT) gives us a predictive power to estimate the future growth of network and insight about the actual dynamics governing the complex ne

P. Jakobsson, J. P. U. Fynbo, C. Ledoux, P. Vreeswijk

Context: Before the launch of the Swift satellite, the majority of the gamma-ray burst (GRB) afterglows for which Ly-alpha was redshifted into the observable spectrum showed evidence for a damped Ly-alpha absorber. This small sample indicated that GRBs explode either in galaxies, or regions within them, having high neutral hydrogen column densities. Aims: To

Mikhail S. Volkov

Classical solutions describing strings endowed with an electric charge and carrying a constant electromagnetic current are constructed within the bosonic sector of the Electroweak Theory. For any given ratio of the Higgs boson mass to W boson mass and for any Weinberg's angle, these strings comprise a family that can be parameterized by values of the cur

A. Altmeyer, S. Riedl, C. Kohstall, M. Wright

We report on precision measurements of the frequency of the radial compression mode in a strongly interacting, optically trapped Fermi gas of Li-6 atoms. Our results allow for a test of theoretical predictions for the equation of state in the BEC-BCS crossover. We confirm recent quantum Monte-Carlo results and rule out simple mean-field BCS theory. Our resul

Andrei Mikhailov

We discuss the bihamiltonian structure of the Metsaev-Tseytlin superstring in AdS_5 x S**5. We explicitly write down the boost-invariant symplectic structure for the superstring in AdS_5 x S**5 and explain its relation to the standard (canonical) symplectic structure. We discuss the geometrical meaning of the boost-invariant symplectic structure for the boso

D. A. Garanin

The problem of the phonon bottleneck in the relaxation of two-level systems (spins) to a narrow group of resonant phonons via emission-absorption processes is investigated from the first principles. It is shown that the kinetic approach based on the Pauli master equation is invalid because of the narrow distribution of the phonons exchanging their energy wit

Idan Ginsburg, Abraham Loeb

Recent surveys have identified seven hypervelocity stars (HVSs) in the halo of the Milky Way. Most of these stars may have originated from the breakup of binary star systems by the nuclear black hole SgrA*. In some instances, the breakup of the binary may lead to a collision between its member stars. We examine the dynamical properties of these collisions by

Radu Ionicioiu

The parity gate emerged recently as a promising resource for performing universal quantum computation with fermions using only linear interactions. Here we analyse the parity gate (P-gate) from a theoretical point of view in the context of quantum networks. We present several schemes for entanglement generation with P-gates and show that native networks simp

Christopher Savage, Katherine Freese, William H. Kinney

The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest version takes the form $V(ϕ) = Λ^4 [1 \pm \cos(Nϕ/f)]$. The model agrees with WMAP3 measurements as long as $f > 0.7 m_{P

Gustavo Burdman, Z. Chacko, Hock-Seng Goh, Roni Harnik

We present a new class of models that stabilize the weak scale against radiative corrections up to scales of order 5 TeV without large corrections to precision electroweak observables. In these `folded supersymmetric' theories the one loop quadratic divergences of the Standard Model Higgs field are cancelled by opposite spin partners, but the gauge quant

E. M. Motoyama, G. Yu, I. M. Vishik, O. P. Vajk

High-transition-temperature (high-Tc) superconductivity develops near antiferromagnetic phases, and it is possible that magnetic excitations contribute to the superconducting pairing mechanism. To assess the role of antiferromagnetism, it is essential to understand the doping and temperature dependence of the two-dimensional antiferromagnetic spin correlatio

Hongyu He

We study the restrictions of certain degenerate principal series representations of the universal covering of the symplectic group. We construct an isometry between the complementary series and the unitary principal series which preserves the action of a symplectic subgroup no bigger than half of the size of the original group.

B. Basu-Mallick, K. S. Gupta, S. Meljanac, A. Samsarov

We analyze a generalization of the quantum Calogero model with the underlying conformal symmetry, paying special attention to the two-body model deformation. Owing to the underlying $ SU(1,1) $ symmetry, we find that the analytic solutions of this model can be described within the scope of the Bargmann representation analysis and we investigate its dynamical

Andre H. Hoang, Pedro Ruiz-Femenia

We discuss the form and construction of general color singlet heavy particle-antiparticle pair production currents for arbitrary quantum numbers, and issues related to evanescent spin operators and scheme-dependences in nonrelativistic QCD (NRQCD) in n=3-2epsilon dimensions. The anomalous dimensions of the leading interpolating currents for heavy quark and c

P. Deift, A. Its, I. Krasovsky

The authors use Riemann-Hilbert methods to compute the constant that arises in the asymptotic behavior of the Airy-kernel determinant of random matrix theory.

Miroslav Micic, Tom Abel, Steinn Sigurdsson

Primordial stars are likely to be very massive >30 Msun, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos. We expect primordial stars to form in halos in the mass range 10^6-10^10 Msun. Some of these early black holes, formed at redshifts z>10, could be the seed black hole for a significant fract

Yemon Choi

Certain semigroups are known to admit a `strong semilattice decomposition' into simpler pieces. We introduce a class of Banach algebras that generalise the $\ell^1$-convolution algebras of such semigroups, and obtain a disintegration theorem for their simplicial homology. Using this we show that for any Clifford semigroup $S$ of amenable groups, $\lp{1}(S)$

John F. Duncan

We introduce the notion of vertex operator superalgebra with enhanced conformal structure, which is a refinement of the notion of vertex operator superalgebra. We exhibit several examples, including a particular one which is self-dual, and whose full symmetry group is a direct product of a cyclic group of order seven with the sporadic simple group of Rudvali

Hunter Monroe

Causality violations are typically seen as unrealistic and undesirable features of a physical model. The following points out three reasons why causality violations, which Bonnor and Steadman identified even in solutions to the Einstein equation referring to ordinary laboratory situations, are not necessarily undesirable. First, a space-time in which every c

Justin R. David, Dileep P. Jatkar, Ashoke Sen

We find the exact spectrum of a class of quarter BPS dyons in a generic N=4 supersymmetric Z_N orbifold of type IIA string theory on K3\times T^2 or T^6. We also find the asymptotic expansion of the statistical entropy to first non-leading order in inverse power of charges and show that it agrees with the entropy of a black hole carrying same set of charges

Dariusz Prorok

Three possible scenarios of the statistical hadronization model are reexamined with the use of the $p_{T}$ spectra of the PHENIX and very low $p_{T}$ PHOBOS measurements at $\sqrt{s_{NN}}=200$ GeV. These scenarios are: (\textit{a}) full chemical non-equilibrium, (\textit{b}) strangeness chemical non-equilibrium and (\textit{c}) chemical equilibrium. Fits to

Ralf Metzler, Tobias Ambjoernsson, Andreas Hanke, Yongli Zhang

From a nanoscience perspective, cellular processes and their reduced in vitro imitations provide extraordinary examples for highly robust few or single molecule reaction pathways. A prime example are biochemical reactions involving DNA molecules, and the coupling of these reactions to the physical conformations of DNA. In this review, we summarise recent res

Christopher D. Carone, Marc Sher, Marc Vanderhaeghen

Violations of Lorentz invariance that appear via operators of dimension four or less are completely parameterized in the Standard Model Extension (SME). In the pure photonic sector of the SME, there are nineteen dimensionless, Lorentz-violating parameters. Eighteen of these have experimental upper bounds ranging between 10^{-11} and 10^{-32}; the remaining p

E. G. S. Luna

We discuss some phenomenological applications of an infrared finite gluon propagator characterized by a dynamically generated gluon mass. In particular we compute the effect of the dynamical gluon mass on $pp$ and ${\bar{p}}p$ diffractive scattering. We also show how the data on $γp$ photoproduction and hadronic $γγ$ reactions can be derived from the $pp$ an

Gyula Fodor, István Rácz

Preliminary results concerning the time evolution of strongly exited SU(2) Bogomolny-Prasad-Sommerfield (BPS) magnetic monopoles have been published in Phys. Rev. Lett. 92, 151801 (2004). The behavior of these dynamical magnetic monopoles was investigated by means of numerical simulations in the four dimensional Minkowski spacetime. The developed code incorp

John Veysey, Nigel Goldenfeld

The seemingly simple problem of determining the drag on a body moving through a very viscous fluid has, for over 150 years, been a source of theoretical confusion, mathematical paradoxes, and experimental artifacts, primarily arising from the complex boundary layer structure of the flow near the body and at infinity. We review the extensive experimental and

P. Chigansky, R. Liptser

Let $σ(u)$, $u\in \mathbb{R}$ be an ergodic stationary Markov chain, taking a finite number of values $a_1,...,a_m$, and $b(u)=g(σ(u))$, where $g$ is a bounded and measurable function. We consider the diffusion type process $$ dX^ε_t = b(X^ε_t/ε)dt + ε^κσ\big(X^ε_t/ε\big)dB_t, t\le T $$ subject to $X^ε_0=x_0$, where $ε$ is a small positive parameter, $B_t$ i

K. Thamilmaran, D. V. Senthilkumar, A. Venkatesan, M. Lakshmanan

We have identified the three prominent routes, namely Heagy-Hammel, fractalization and intermittency routes, and their mechanisms for the birth of strange nonchaotic attractors (SNAs) in a quasiperiodically forced electronic system constructed using a negative conductance series LCR circuit with a diode both numerically and experimentally. The birth of SNAs

Helmut G. Katzgraber, Lik Wee Lee, I. A. Campbell

Monte Carlo data of the two-dimensional Ising spin glass with bimodal interactions are presented with the aim of understanding the low-temperature physics of the model. An analysis of the specific heat, spin-glass susceptibility, finite-size correlation length, and the Binder ratio is performed to try to verify a recent proposal in which for large system siz

F. Ya. Khalili

A relatively simple method of overcoming the Standard Quantum Limit in the next-generation Advanced LIGO gravitational wave detector is considered. It is based on the quantum variational measurement with a single short (a few tens of meters) filter cavity. Estimates show that this method allows to reduce the radiation pressure noise at low frequencies ($<100

Jaume Masoliver, Josep Perello

We present a detailed study on the mean first-passage time of volatility processes. We analyze the theoretical expressions based on the most common stochastic volatility models along with empirical results extracted from daily data of major financial indices. We find in all these data sets a very similar behavior that is far from being that of a simple Wiene

A. Vernes, B. L. Gyorffy, P. Weinberger

It is shown that a useful relativistic generalization of the conventional spin density for the case of moving electrons is the expectation value of the four-component Bargmann-Wigner polarization operator. An exact equation of motion for this quantity is derived, using the one-particle Dirac equation, and the relativistic analogues of the non-relativistic co

M. Sereno, F. De Luca

We present an analytical treatment of gravitational lensing by a Kerr black hole in the weak deflection limit. Lightlike geodesics are expanded as a Taylor series up to and including third-order terms in m/b and a/b, where m is the black hole mass, a the angular momentum and b the impact parameter of the light ray. Positions and magnifications of individual

F. T. Brandt, M. R. Elias-Filho

We obtain the leading order interaction between the graviton and the neutral scalar boson in the context of noncommutative field theory. Our approach makes use of the Ward identity associated with the invariance under a subgroup of symplectic diffeomorphisms.

S. F. King, J. P. Roberts

In this talk we analyse the claim that supersymmetry (SUSY) naturally accounts for the observed dark matter density. In many cases, it is necessary to tune the parameters of a SUSY model to fit the WMAP data. We provide a quantitative analysis of the degree of tuning required for different annihilation channels. Some regions are natural, requiring no tuning

Claude Viallet

We give the basic definition of algebraic entropy for lattice equations. The entropy is a canonical measure of the complexity of the dynamics they define. Its vanishing is a signal of integrability, and can be used as a powerful integrability detector. It is also conjectured to take remarkable values (algebraic integers).