June 2007 arXiv papers — page 40

Jose J. Blanco-Pillado, Alberto Iglesias, Warren Siegel

We explore the relation between classical and quantum states in both open and closed (super)strings discussing the relevance of coherent states as a semiclassical approximation. For the closed string sector a gauge-fixing of the residual world-sheet rigid translation symmetry of the light-cone gauge is needed for the construction to be possible. The circular

D. A. Parshin, V. L. Gurevich, H. R. Schober

We show that the same physical mechanism is fundamental for two seemingly different phenomena such as the formation of two-level systems in glasses and the Boson peak in the reduced density of low-frequency vibrational states g(w)/w^2. This mechanism is the vibrational instability of weakly interacting harmonic modes. Below some frequency w_c << w_0 (where w

Christina Markert

Results of resonance particle production measured at RHIC in $\sqrt{s_{\rm NN}} = $ 200 GeV Au+Au collisions are compared to measurements in p+p and d+Au collisions in order to verify the existence of an extended hardronically interacting medium. Yield and momentum distributions of resonances maybe modified during the fireball lifetime due to resonance decay

Shirley Ho, Yen-Ting Lin, David Spergel, Christopher M. Hirata

We investigate statistical properties of LRGs in a sample of X-ray selected galaxy clusters at intermediate redshift ($0.2\le z\le0.6$). The LRGs are selected based on carefully designed color criteria, and the cluster membership is assessed via photometric redshifts. As clusters and LRGs are both viewed as promising tracer of the underlying dark matter dist

Lawrence E. Kidder, Luc Blanchet, Bala R. Iyer

In this Comment we compute the contributions of the radiation reaction force in the 2.5 post-Newtonian (PN) gravitational wave polarizations for compact binaries in circular orbits. (i) We point out and correct an inconsistency in the derivation of Arun, Blanchet, Iyer, and Qusailah. (ii) We prove that all contributions from radiation reaction in the 2.5PN w

Christina Markert

Hadronic resonances with short life times and strong coupling to the dense medium may exhibit mass shifts and width broadening as signatures of chiral symmetry restoration at the phase transition between hadronic and partonic matter. Resonances with different lifetimes are also used to extract information about the time evolution and temperature of the expan

Nicolas Bartholdi, Jérémy Blanc, Sébastien Loisel

We give some new advances in the research of the maximum number of triangles that we may obtain in a simple arrangements of n lines or pseudo-lines.

V. V. Bavula

The Jacobian algebras are introduced and their various properties are studied.

Ram Rajagopal, Martin J. Wainwright

We consider the following problem of decentralized statistical inference: given i.i.d. samples from an unknown distribution, estimate an arbitrary quantile subject to limits on the number of bits exchanged. We analyze a standard fusion-based architecture, in which each of $m$ sensors transmits a single bit to the fusion center, which in turn is permitted to

Morrel H. Cohen, Adam Wasserman, Kieron Burke

We illustrate the main features of a recently proposed method based on ensemble density functional theory to divide rigorously a complex molecular system into its parts [M.H. Cohen and A. Wasserman, J. Phys. Chem. A 111, 2229 (2007)]. The illustrative system is an analog of the hydrogen molecule for which analytic expressions for the densities of the parts (

M. M. Miller Bertolami, L. G. Althaus

We analyze the robustness of H--deficient post--AGB tracks regarding previous evolution of their progenitor stars and the constitutive physics of the remnants. Our motivation is a recent suggestion of Werner & Herwig (2006) that previous evolution should be important in shaping the final post--AGB track and the persisting discrepancy between asteroseismologi

Jamie Vicary

This paper describes how the structure of the state space of the quantum harmonic oscillator can be described by an adjunction of categories, that encodes the raising and lowering operators into a commutative comonoid. The formulation is an entirely general one in which Hilbert spaces play no special role. Generalised coherent states arise through the hom-se

Richard L. Hall, Wolfgang Lucha

General analytic energy bounds are derived for N-boson systems governed by ultrarelativistic Hamiltonians of the form H = sum_{i=1}^N||p_i|| + sum_{1=i<j}^N V(r_{ij}), where V(r) is a static attractive pair potential. It is proved that a translation-invariant model Hamiltonian H_c provides a lower bound to H for all N \ge 2. This result was conjectured in an

A. Kleine, C. Kollath, I. McCulloch, T. Giamarchi

We show that one of the key characteristics of interacting one-dimensional electronic quantum systems, the separation of spin and charge, can be observed in a two-component system of bosonic ultracold atoms even close to a competing phase separation regime. To this purpose we determine the real-time evolution of a single particle excitation and the single-pa

Fabio Ferrari Ruffino

Given a Gelfand pair of Lie groups, we identify the spectrum with a suitable subset of C^n and we prove the equivalence between Gelfand topology and euclidean topology.

T. S. Cubitt, A. Montanaro, A. Winter

We consider the question of how large a subspace of a given bipartite quantum system can be when the subspace contains only highly entangled states. This is motivated in part by results of Hayden et al., which show that in large d x d--dimensional systems there exist random subspaces of dimension almost d^2, all of whose states have entropy of entanglement a

M. Z. Garaev

Let $\mathbb{F}_p$ be the field of a prime order $p.$ It is known that for any integer $N\in [1,p]$ one can construct a subset $A\subset\mathbb{F}_p$ with $|A|= N$ such that $$ \max\{|A+A|, |AA|\}\ll p^{1/2}|A|^{1/2}. $$ In the present paper we prove that if $A\subset \mathbb{F}_p$ with $|A|>p^{2/3},$ then $$ \max\{|A+A|, |AA|\}\gg p^{1/2}|A|^{1/2}. $$

Ursula Bassler

An overview of latest top quark pair production cross-sections measured at the Tevatron is given. These measurements have been carried out in the dilepton, lepton+jets and all-jets channels with an integrated luminosity of about 1fb-1. The measurements are consistent with NNLO calculations.

A Verma, N K Sharma, A Pathak

Since the introduction of binomial state as an intermediate state, different intermediate states have been proposed. Different nonclassical effects have also been reported in these intermediate states. But till now higher order antibunching or higher order subpoissonian photon statistics is predicted only in one type of intermediate state, namely shadowed ne

Ewald Puchwein, Matthias Bartelmann

We show how hydrostatic equilibrium in galaxy clusters can be quantitatively probed combining X-ray, SZ, and gravitational-lensing data. Our previously published method for recovering three-dimensional cluster gas distributions avoids the assumption of hydrostatic equilibrium. Independent reconstructions of cumulative total-mass profiles can then be obtained

Joerg Jaeckel, Andreas Ringwald

We present a scheme to extend the sensitivity of axion-photon regeneration experiments towards larger masses with the help of properly chosen and placed phase shift plates.

C. S. Nelson, H. Mo, B. Bohnenbuck, J. Strempfer

We report x-ray scattering studies of the c-axis lattice parameter in Ca3Ru2O7 as a function of temperature and magnetic field. These structural studies complement published transport and magnetization data, and therefore elucidate the spin-charge-lattice coupling near the metal-insulator transition. Strong anisotropy of the structural change for field appli

Jan Gomulkiewicz, Jacek Miekisz, Stanislaw Miekisz

We discuss various models of ion transport through cell membrane channels. Recent experimental data shows that sizes of ion channels are compared to those of ions and that only few ions may be simultaneously in any single channel. Theoretical description of ion transport in such channels should therefore take into account interactions between ions and betwee

Marat V. Burnashev

A new approach for upper bounding the channel reliability function using the code spectrum is described. It allows to treat both low and high rate cases in a unified way. In particular, the earlier known upper bounds are improved, and a new derivation of the sphere-packing bound is presented.

Abdelhamid Hassairi, Sallouha Lajmi, Raoudha Zine

Bobecka and Wesolowski (2002) have shown that, in the Olkin and Rubin characterization of the Wishart distribution (See Casalis and Letac (1996)), when we use the division algorithm defined by the quadratic representation and replace the property of invariance by the existence of twice differentiable densities, we still have a characterization of the Wishart

Thierry Coulbois, Arnaud Hilion, Martin Lustig

This is the third of a series of three articles where we introduce laminations for the free-groups. We explore here the link between currents and laminations and prove that the situation is more complicated than in the surface case of real tree dual to a measured geodesic lamination.

Christina C. Thoene, Johan P. U. Fynbo

We present a study of the host galaxy of the Gamma-Ray Burst (GRB) of May 5 2006 (GRB 060505). The host is spatially resolved in both imaging data and in a long slit spectrum including the GRB site. We find the galaxy to be a Sbc spiral, which is unusual for a long GRB host galaxy. The site of the GRB is considerably different from the rest of the galaxy wit

Daryl Cooper, Stephan Tillmann

Given a triangulation of a closed, oriented, irreducible, atoroidal 3-manifold every oriented, incompressible surface may be isotoped into normal position relative to the triangulation. Such a normal oriented surface is then encoded by non-negative integer weights, 14 for each 3-simplex, that describe how many copies of each oriented normal disc type there a

T. Sidery, N. Andersson, G. L. Comer

We discuss wave propagation in rotating superfluid neutron star cores, taking into account the vortex mediated mutual friction force. For models where the two fluids co-rotate in the unperturbed state, our analysis clarifies the role of chemical coupling and entrainment for sound and inertial waves. We also investigate the mutual friction damping, providing

Ofer Gabber, Fabrice Orgogozo

Let A be an excellent integral henselian local noetherian ring, k its residue field of characteristic p>0 and K its fraction field. Using an algebraization technique introduced by the first named author, and the one-dimension case already proved by Kazuya KATO, we prove the following formula: cd_p(K) = dim(A) + p-rank(k), if k is separably closed and K of ch

V. M. Kolomietz, S. V. Lukyanov, O. O. Khudenko

Model independent, $m_1$, adiabatic, $m_{-1}$, and high-energy, $m_3$, energy weighted sums for the isoscalar and isovector nuclear excitations are investigated within the framework of the kinetic theory adopted to the description of a two-component nuclear Fermi-liquid. For both the adiabatic and scaling approaches, the connection of the EWS $m_{-1}$ and $m

S. R. Oates, M. De Pasquale, M. J. Page, A. J. Blustin

This paper investigates GRB 050802, one of the best examples of a it Swift gamma-ray burst afterglow that shows a break in the X-ray lightcurve, while the optical counterpart decays as a single power-law. This burst has an optically bright afterglow of 16.5 magnitude, detected throughout the 170-650nm spectral range of the UVOT on-board Swift. Observations b

I. P. Lokhtin, S. V. Petrushanko, A. M. Snigirev, C. Yu. Teplov

The model to simulate rescattering and partonic energy loss in ultrarelativistic heavy ion collisions is presented. The full heavy ion event is obtained as a superposition of a soft hydro-type state and hard multi-jets. This model is capable of reproducing main features of the jet quenching pattern at RHIC, and is applied to probe jet quenching in various no

O. Bundau, M. Neamtu, D. Opris

We consider the static and dynamic models of Cournot duopoly with tax evasion. In the dynamic model we introduce the time delay and we analyze the local stability of the stationary state. There is a critical value of the delay when the Hopf bifurcation occurs.

E. Kirkman, J. Kuzmanovich, J. J. Zhang

We prove a graded version of Alev-Polo&#39;s rigidity theorem: the homogenization of the universal enveloping algebra of a semisimple Lie algebra and the Rees ring of the Weyl algebras $A_n(k)$ cannot be isomorphic to their fixed subring under any finite group action. We also show the same result for other classes of graded regular algebras including the Skl

N. A. Hatch, C. S. Crawford, A. C. Fabian

We present IFU observations of six emission-line nebulae that surround the central galaxy of cool core clusters. Qualitatively similar nebulae are observed in cool core clusters even when the dynamics and possibly formation and excitation source are different. Evidence for a nearby secondary galaxy disturbing a nebula, as well as AGN and starburst driven out

Angel J. Moreno, Christos N. Likos

For a large class of fluids exhibiting ultrasoft bounded pair potentials, particles form crystals consisting of clusters located in the lattice sites, with a density-independent lattice constant. Here we present an investigation on the dynamic features of a representative example of this class. It is found that particles can diffuse between lattice sites, ma

R. Salvaterra, S. Campana, G. Chincarini, G. Tagliaferri

We compute the probability to detect long Gamma Ray Bursts (GRBs) at z>5 with Swift, assuming that GRBs form preferentially in low-metallicity environments. The model fits well both the observed BATSE and Swift GRB differential peak flux distribution and is consistent with the number of z>2.5 detections in the 2-year Swift data. We find that the probability

Edward Odell, Thomas Schlumprecht, András Zsák

For a countable ordinal a we denote by C_a the class of separable, reflexive Banach spaces whose Szlenk index and the Szlenk index of their dual are bounded by a. We show that each C_a admits a separable, reflexive universal space. We also show that spaces in the class C_{omega^{a*omega}} embed into spaces of the same class with a basis. As a consequence we

Gerhard Baur, Kai Hencken, Dirk Trautmann

In recent years, a large number of papers have appeared that dealt with $\EPEM$ pair production in heavy ion collisions at high energies. To a large extent these studies were motivated by the existence of relativistic heavy ion accelerators all over the world. There pair production can be studied in so called ``ultra-peripheral collisions&#39;&#39;, where th

Edward Odell, Thomas Schlumprecht, András Zsák

We consider the following two-player game played on a separable, infinite-dimensional Banach space X. Player S chooses a positive integer k_1 and a finite-codimensional subspace X_1 of X. Then player P chooses x_1 in the unit sphere of X_1. Moves alternate thusly, forever. We study this game in the following setting. Certain normalized, 1-unconditional seque

E. G. Noya, C. Vega, J. P. K. Doye, A. A. Louis

We computed the phase diagram for a system of model anisotropic particles with six attractive patches in an octahedral arrangement. We chose to study this model for a relatively narrow value of the patch width where the lowest-energy configuration of the system is a simple cubic crystal. At this value of the patch width, there is no stable vapour-liquid phas

Raul Jimenez, Haydee Lugo, Jose A. Cuesta, Angel Sanchez

We study the problem of the emergence of cooperation in the spatial Prisoner&#39;s Dilemma. The pioneering work by Nowak and May showed that large initial populations of cooperators can survive and sustain cooperation in a square lattice with imitate-the-best evolutionary dynamics. We revisit this problem in a cost-benefit formulation suitable for a number o

Satendra Pal Singh, Dhananjai Pandey, Songhak Yoon, Sunggi Baik

The existing controversy about the room temperature structure of multiferroic Pb(Fe_1/2Nb_1/2)O_3 is settled using synchrotron powder x-ray diffraction data. Results of Rietveld refinements in the temperature range 300 to 12K reveal that the structure remains monoclinic in the Cm space group down to 12K, but the lattice parameters show anomalies at the magne

P. Napolitani, K. -H. Schmidt, L. Tassan-Got, P. Armbruster

We present an extensive overview of production cross sections and kinetic energies for the complete set of nuclides formed in the spallation of 136Xe by protons at the incident energy of 1 GeV per nucleon. The measurement was performed in inverse kinematics at the FRagment Separator (GSI, Darmstadt). Slightly below the Businaro-Gallone point, 136Xe is the st

Stefan Ask

The ATLAS experiment at the LHC is building several detector systems for forward physics studies and to determine the luminosity. The main forward systems consist of a Cerenkov detector called LUCID, a Zero Degree Calorimeter (ZDC) and Roman Pots which will house a scintillating fiber tracker system called ALFA. Here we report some of the forward physics act

Dietrich Stauffer, Christian Schulze, Dieter W. Heermann

We present a model for diffusion in a molecularly crowded environment. The model consists of random barriers in percolation network. Random walks in the presence of slowly moving barriers show normal diffusion for long times, but anomalous diffusion at intermediate times. The effective exponents for square distance versus time usually are below one at these

Tamiaki Yoneya

In connection with the space-time uncertainty principle which gives a simple qualitative characterization of non-local or non-commutative nature of short-distance space-time structure in string theory, author&#39;s recent approaches toward field theories for D-branes are briefly outlined, putting emphasis on some key ideas lying in the background. The final

Jose Luis Iribarren, Esteban Moro

The dynamics of information dissemination in social networks is of paramount importance in processes such as rumors or fads propagation, spread of product innovations or "word-of-mouth" communications. Due to the difficulty in tracking a specific information when it is transmitted by people, most understanding of information spreading in social networks come

Lars Andersson, Thierry Barbot, Riccardo Benedetti, Francesco Bonsante

These notes are a companion to the article &#34;Lorentz spacetimes of constant curvature&#34; by Geoffrey Mess, which was first written in 1990 but never published. Mess&#39; paper will appear together with these notes in a forthcoming issue of Geometriae Dedicata.

Luigi Martina, Alexander Protogenov, Valery Verbus

We consider universal statistical properties of systems that are characterized by phase states with macroscopic degeneracy of the ground state. A possible topological order in such systems is described by non-linear discrete equations. We focus on the discrete equations which take place in the case of generalized exclusion principle statistics. We show that

Philippe Nuss, Marc Wambst

We introduce and study non-abelian cohomology sets of Hopf algebras with coefficients in Hopf comodule algebras. We prove that these sets generalize as well Serre&#39;s non-abelian group cohomology theory as the cohomological theory constructed by the authors in a previous article. We establish their functoriality and compute explicit examples. Further we cl

Christos Eleftheriadis

Axions are expected to be produced in the sun via the Primakoff process. They may be detected through the inverse process in the laboratory, under the influence of a strong magnetic field, giving rise to X-rays of energies in the range of a few keV. Such an Axion detector is the CERN Axion Solar Telescope (CAST), collecting data since 2003. Results have been

Carlotta Giusti, Franco Davide Pacati, Michael Schwamb, Sigfrido Boffi

Results for the cross sections of the exclusive 16O(e,e&#39;pn)14N and 16O(gamma,pn)14N knockout reactions are presented and discussed in different kinematics. In comparison with earlier work, a complete treatment of the center-of-mass (CM) effects in the nuclear one-body current is considered in connection with the problem of the lack of orthogonality betwe

Shipra, A. Gomathi, A. Sundaresan, C. N. R. Rao

Nanoparticles of superconducting YBa2Cu3O7-delta (YBCO) (Tc = 91 K) exhibit ferromagnetism at room temperature while the bulk YBCO, obtained by heating the nanoparticles at high temperature (940 degree C), shows a linear magnetization curve. Across the superconducting transition temperature, the magnetization curve changes from that of a soft ferromagnet to

P. Holicky, O. Kalenda, L. Vesely, L. Zajicek

On each nonreflexive Banach space X there exists a positive continuous convex function f such that 1/f is not a d.c. function (i.e., a difference of two continuous convex functions). This result together with known ones implies that X is reflexive if and only if each everywhere defined quotient of two continuous convex functions is a d.c. function. Our const

David Angeli, Pierre-Alexandre Bliman

The present paper is devoted to estimating the speed of convergence towards consensus for a general class of discrete-time multi-agent systems. In the systems considered here, both the topology of the interconnection graph and the weight of the arcs are allowed to vary as a function of time. Under the hypothesis that some spanning tree structure is preserved

Victor Dotsenko

A brief survey of the theoretical, numerical and experimental studies of the random field Ising model during last three decades is given. Nature of the phase transition in the three-dimensional RFIM with Gaussian random fields is discussed. Using simple scaling arguments it is shown that if the strength of the random fields is not too small (bigger than a ce

Douglas M. Gingrich

Black hole production at the Large Hadron Collider (LHC) is an interesting consequence of TeV-scale gravity models. The predicted values, or lower limits, for the fundamental Planck scale and number of extra dimensions will depend directly on the accuracy of the black hole production cross-section. We give a range of lower limits on the fundamental Planck sc

M. Kaniber, A. Kress, M. Bichler, R. Meyer

We investigate the modification of the spontaneous emission dynamics and external quantum efficiency for self-assembled InGaAs quantum dots coupled to extended and localised photonic states in GaAs 2D-photonic crystals. The 2D-photonic bandgap is shown to give rise to a 5-10 times enhancement of the external quantum efficiency whilst the spontaneous emission

L. Vesely, L. Zajicek

A d.c. (delta-convex) function on a normed linear space is a function representable as a difference of two continuous convex functions. We show that an infinite dimensional analogue of Hartman&#39;s theorem on stability of d.c. functions under compositions does not hold in general. However, we prove that it holds in some interesting particular cases. Our mai

D. I. Bradley, D. O. Clubb, S. N. Fisher, A. M. Guénault

We describe measurements of the decay of pure superfluid turbulence in superfluid 3He-B, in the low temperature regime where the normal fluid density is negligible. We follow the decay of the turbulence generated by a vibrating grid as detected by vibrating wire resonators. Despite the absence of any classical normal fluid dissipation processes, the decay is

D. A. Gouliermis, Th. Henning, W. Brandner, M. R. Rosa

The Magellanic Clouds (MCs) offer an outstanding variety of young stellar associations, in which large samples of low-mass stars (with masses less than 1 solar mass) currently in the act of formation can be resolved and explored sufficiently with the Hubble Space Telescope. These pre-main sequence (PMS) stars provide a unique snapshot of the star formation p

Andrew J. Archer, Nigel B. Wilding

Fluids in which the interparticle potential has a hard core, is attractive at moderate separations, and repulsive at greater separations are known to exhibit novel phase behavior, including stable inhomogeneous phases. Here we report a joint simulation and theoretical study of such a fluid, focusing on the relationship between the liquid-vapor transition lin

V. M. Lashkin

Two-dimensional (2D) equations describing the nonlinear interaction between upper-hybrid and dispersive magnetosonic waves are presented. Nonlocal nonlinearity in the equations results in the possibility of existence of stable 2D nonlinear structures. A rigorous proof of the absence of collapse in the model is given. We have found numerically different types

C. Fernandez-Ramirez, E. Moya de Guerra, J. M. Udias

We analyze the $γp \to ηp$ process from threshold up to 1.2 GeV, employing an effective Lagrangian approach that allows for a mixing of eta couplings of pseudoscalar and pseudovector nature. The mixing ratio of the couplings may serve as a quantitative estimation of the $SU_L(3)\times SU_R(3)$ extended chiral symmetry violation in this energy regime. The dat

Michael Pawellek

We consider the algebraic form of a generalized Lame equation with five free parameters. By introducing a generalization of Jacobi&#39;s elliptic functions we transform this equation to a 1-dim time-independent Schroedinger equation with (quasi-doubly) periodic potential. We show that only for a finite set of integral values for the five parameters quasi-dou

Remco van der Hofstad, Mark Holmes, Gordon Slade

We extend the inductive approach to the lace expansion, previously developed to study models with critical dimension 4, to be applicable more generally. In particular, the result of this note has recently been used to prove Gaussian asymptotic behaviour for the Fourier transform of the two-point function for sufficiently spread-out lattice trees in dimension

Attila Andai

In this paper we consider the space of those probability distributions which maximize the $q$-Rényi entropy. These distributions have the same parameter space for every $q$, and in the $q=1$ case these are the normal distributions. Some methods to endow this parameter space with Riemannian metric is presented: the second derivative of the $q$-Rényi entropy,

A. Nucara, P. Maselli, M. Del Bufalo, M. Cestelli Guidi

In a metallic manganite like La(2/3)Sr(1/3)MnO(3), the substitution of Mn(+3) by Ga(+3) dilutes the ferromagnetic order and locally cancels the Jahn-Teller distortion, without heavily affecting the crystal structure. One can thus follow the changes in the charge dynamics induced by Ga, until the ferro-metallic manganite is turned into an insulator. Here this

Debabrata Pal, Sk. Golam Ali, B. Talukdar

We use a variational method to construct soliton solutions for systems characterized by opposing dispersion and competing nonlinearities at fundamental and second harmonics. We show that both ordinary and embedded solitons tend to gain energy when the second harmonic field becomes weaker than the first harmonic field.

Mark Agranovsky, Peter Kuchment

The paper contains a simple approach to reconstruction in Thermoacoustic and Photoacoustic Tomography. The technique works for any geometry of point detectors placement and for variable sound speed satisfying a non-trapping condition. A uniqueness of reconstruction result is also obtained.

Yoann Gasteuil, Woodrow Shew, Mathieu Gibert, Francesca Chilla

We have developed a small, neutrally buoyant, wireless temperature sensor. Using a camera for optical tracking, we obtain simultaneous measurements of position and temperature of the sensor as it is carried along by the flow in Rayleigh-Bénard convection, at $Ra \sim 10^{10}$. We report on statistics of temperature, velocity, and heat transport in turbulent

L. Martinez Alonso, E. Medina

An iterative algorithm for determining a class of solutions of the dispersionful 2-Toda hierarchy characterized by string equations is developed. This class includes the solution which underlies the large N-limit of the Hermitian matrix model in the one-cut case. It is also shown how the double scaling limit can be naturally formulated in this scheme

Francisco Navarro-Lerida

We present perturbative charged rotating 5D Einstein-Maxwell black holes with spherical horizon topology. The electric charge Q is the perturbative parameter, the perturbations being performed up to 4th order. The expressions for the relevant physical properties of these black holes are given. The gyromagnetic ratio g, in particular, is explicitly shown to b

A. Yu. Olshanskii

Let F be a field and A a free associative F-algebra or a group algebra of a free group with an infinite set X of generators. We find a necessary and sufficient condition for the inclusion I&#39; into I, where I=I_1...I_k and I&#39;=I&#39;_1...I&#39;_l are any products of T-ideals in A. A canonical reformulation in terms of products of group representation va

Cai-Dian Lu

The perturbative QCD approach is based on $k_T$ factorization, including the Sudakov form factors so that to avoid the endpoint singularity. In this approach, we calculate the charmless B decays like $B\to ππ$ decays etc. to produce the right number of branching ratios and also CP asymmetry parameters. For final states with at least one charmed meson, like $

Jesus Inarrea

We theoretically analyzed the microwave-induced modification of the Hall magnetoresistivity in high mobility two-dimensional electron systems. These systems present diagonal magnetoresistivity oscillations and zero-resistance states when are subjected to microwave radiation. The most surprising modification of the Hall magnetoresistivity is a periodic reduct

W. Y. So, T. Udagawa, K. S. Kim, S. W. Hong

Simultaneous $χ^{2}$ analyses previously made for elastic scattering and fusion cross section data for the $^{6}$Li+$^{208}$Pb system is extended to the $^{7}$Li+$^{208}$Pb system at near-Coulomb-barrier energies based on the extended optical model approach, in which the polarization potential is decomposed into direct reaction (DR) and fusion parts. Use is

Zhendong Zhao, Lei Yuan, Yuxuan Wang, Forrest Sheng Bao

In the process of training Support Vector Machines (SVMs) by decomposition methods, working set selection is an important technique, and some exciting schemes were employed into this field. To improve working set selection, we propose a new model for working set selection in sequential minimal optimization (SMO) decomposition methods. In this model, it selec

I. Corro, N. G. Parker, A. M. Martin

We theoretically examine the rotation of an atomic Bose-Einstein condensate in an elliptical trap, both in the absence and presence of a quantized vortex. Two methods of introducing the rotating potential are considered - adiabatically increasing the rotation frequency at fixed ellipticity, and adiabatically increasing the trap ellipticity at fixed rotation

Zahid Hasan Mahmood, A. P. Shah, Abdul Kadir, M. R. Gokhale

Band discontinuities at the InN-GaN heterointerface are experimentally determined from internal photoemission spectroscopy measurements on n+ InN on GaN epilayers. The photocurrent shows two threshold energies, one at 1.624 eV and the other at 2.527 eV. From these we obtain the valence band offset 0.85 eV and the conduction band offset 1.82 eV.

Vincent Colin, Ko Honda

We prove that any mapping class on a compact oriented surface with nonempty boundary can be made pseudo-Anosov and right-veering after a sequence of positive stabilizations.

J. A. De Loera, J. Lee, S. Margulies, S. Onn

Systems of polynomial equations over the complex or real numbers can be used to model combinatorial problems. In this way, a combinatorial problem is feasible (e.g. a graph is 3-colorable, hamiltonian, etc.) if and only if a related system of polynomial equations has a solution. In the first part of this paper, we construct new polynomial encodings for the p

T. Shibayama, M. Nohara, H. Aruga Katori, Y. Okamoto

Superconductivity with $T_{\rm c}$ $\simeq$ 2 K was discovered in the intermetallic binary compounds Rh$_2$Ga$_9$ and Ir$_2$Ga$_9$. This is the first observation of superconductivity in the Rh-Ga and Ir-Ga binary systems. Both compounds crystallize in a distorted Co$_2$Al$_9$-type structure (monoclinic, space group: $Pc$), which lacks spatial inversion symme

L. Fox Machado, E. Michel, F. Perez Hernandez, J. H. Pena

We present an analysis of the pulsation behaviour of the Delta Scuti stars 7 Aql (HD 174532) and 8 Aql (HD 174589) -- a new variable star -- observed in the framework of STEPHI XII campaign during 2003 June--July. 183 hours of high precision photometry were acquired by using four-channel photometers at three sites on three continents during 21 days. The ligh

A. Bernui, B. Mota, M. J. Reboucas, R. Tavakol

Recent analyses of the WMAP data seem to indicate the possible presence of large-angle anisotropy in the Universe. If confirmed, these can have important consequences for our understanding of the Universe. A number of attempts have recently been made to establish the reality and nature of such anisotropies in the CMB data. Among these is a directional indica

Sung Guen Kim, Han Ju Lee

We introduce the notion of numerical (strong) peak function and investigate the denseness of the norm and numerical peak functions on complex Banach spaces. Let $A_b(B_X:X)$ be the Banach space of all bounded continuous functions $f$ on the unit ball $B_X$ of a Banach space $X$ and their restrictions $f|_{B_X^\circ}$ to the open unit ball are holomorphic. In

D. A. Adams, R. K. P Zia, B. Schmittmann

As a solvable and broadly applicable model system, the totally asymmetric exclusion process enjoys iconic status in the theory of non-equilibrium phase transitions. Here, we focus on the time dependence of the total number of particles on a 1-dimensional open lattice, and its power spectrum. Using both Monte Carlo simulations and analytic methods, we explore

Bing-Xiao Xu, Xue-Bing Wu

We present a &#34;feedback compression&#34; model to describe the galactic spheroid formation and its relation with the central nuclear activity. We suggest that the star formation itself can serve as the &#34;positive feedback&#34; in some extremely dense region to trigger the starburst. The star formation rate as well as the related stellar feedback-induce

Alexandru Buium, Bjorn Poonen

Given a correspondence between a modular curve and an elliptic curve A we study the group of relations among the CM points of A. In particular we prove that the intersection of any finite rank subgroup of A with the set of CM points of A is finite. We also prove a local version of this global result with an effective bound valid also for certain infinite ran

M. B. Hastings

We show that randomly choosing the matrices in a completely positive map from the unitary group gives a quantum expander. We consider Hermitian and non-Hermitian cases, and we provide asymptotically tight bounds in the Hermitian case on the typical value of the second largest eigenvalue. The key idea is the use of Schwinger-Dyson equations from lattice gauge

G. Galletta, M. D&#39;Alessandro, G. Bertoloni, G. Fanti

We describe the results of the first tests made on LISA, a simulator of planetary environments designed and built in Padua, dedicated to the study of the limit of bacterial life on the planet Mars. Tests on the cryogenic circuit, on the UV illumination and on bacterial coltures at room temperature that shall be used as references are described.

Luis A. Anchordoqui, John F. Beacom, Yousaf M. Butt, Haim Goldberg

TeV gamma-rays can result from the photo-de-excitation of PeV cosmic ray nuclei after their parents have undergone photo-disintegration in an environment of ultraviolet photons. This process is proposed as a candidate explanation of the recently discovered HESS source at the edge of Westerlund 2. The UV background is provided by Lyman-alpha emission within t

Katrin Becker, Melanie Becker, Johannes Walcher

We consider flux compactifications of type IIB string theory on the mirror of a rigid Calabi-Yau. In special cases, these models are dual to the type IIA flux vacua with runaway direction in flux space. We show that new weak coupling AdS solutions can be found for large complex structure, while Minkowski solutions with all moduli stabilized are confined to b

Paul L. H. Cook, Hirosi Ooguri, Jie Yang

We show that a general solution to the extended holomorphic anomaly equations for the open topological string on D-branes in a Calabi-Yau manifold, recently written down by Walcher in arXiv:0705.4098, is obtained from the general solution to the holomorphic anomaly equations for the closed topological string on the same manifold, by shifting the closed strin

Dušan Repovš, Witold Rosicki, Andreas Zastrow, Matjaž Željko

The main result of this paper is that if $X$ is a Peano continuum such that its $n$-th cone $C^n(X)$ embeds into $\RR^{n+2}$ then $X$ embeds into $S^2$. This solves a problem proposed by W. Rosicki.

Gavin E. Crooks

Thermodynamic length is a metric distance between equilibrium thermodynamic states. Among other interesting properties, this metric asymptotically bounds the dissipation induced by a finite time transformation of a thermodynamic system. It is also connected to the Jensen-Shannon divergence, Fisher information and Rao&#39;s entropy differential metric. Theref

Rajendra R. Zope, Tunna Baruah, Mark R. Pederson

We present a detailed investigation of static dipole polarizability of lithium clusters containing up to 22 atoms. We first build a database of lithium clusters by optimizing several candidate structures for the ground state geometry for each size. The full polarizability tensor is determined for about 5-6 isomers of each cluster size using the finite-field

Juergen Reichenbacher

Theoretical calculations predict a small fractional difference in energy loss for $μ^+$ and $μ^-$ of the order of $0.15 %$ at high energies. This is predominantly due to a $z^3$ term in an extended ionization $dE/dX$ relation, in analogy to the Barkas effect at low energies around the Bethe-Bloch maximum. The atmospheric muon energy spectrum is steeply falli