April 2004 arXiv papers — page 10

Albert A. Zijlstra, T. R. Bedding, Andrew J. Markwick, Rita Loidl-Gautschy

The SC and CS stars are thermal-pulsing AGB stars with C/O ratio close to unity. Within this small group, the Mira variable BH Cru recently evolved from spectral type SC (showing ZrO bands) to CS (showing weak C2). Wavelet analysis shows that the spectral evolution was accompanied by a dramatic period increase, from 420 to 540 days, indicating an expanding r

Craig Harrison, Matthew Colless, Warrick J. Couch, B. A. Peterson

We present some preliminary results from an on-going study of the evolution of stellar populations in rich clusters of galaxies. This sample contains core line-strength measurements from 183 galaxies with b_J <= 19.5 from four clusters with <z>~0.04. Using predictions from stellar population models to compare with our measured line strengths we can derive re

Maarten Baes, Herwig Dejonghe, Pieter Buyle, Laura Ferrarese

We investigate the relation between circular velocity vc and bulge velocity dispersion sigma in spiral galaxies, based on literature data and new spectroscopic observations. We find a strong, nearly linear vc-sigma correlation with a negligible intrinsic scatter, and a striking agreement with the corresponding relation for elliptical galaxies. The least mass

Jiulin Du

The effect of nonextensivity of self-gravitating systems on the Jeans criterion for gravitational instability is studied in the framework of Tsallis statistics. The nonextensivity is introduced in the Jeans problem by a generalized q-nonextensive velocity distribution function through the equation of state of ideal gas in nonextensive kinetic theory. A new J

Jiulin Du

The Jeans gravitational instability in nonextensive statistical mechanics is studied and a general form of the generalized Jeans criterion is obtained that is related to the q-function . In this approach, the nonextensive model of classical ideal gas is applied to the Jeans problem instead of the ordinary one in extensive statistical mechanics and the genera

T. Contini, M. Lemoine-Busserolle, R. Pello, J. -F. Le Borgne

We present the first results of a project aiming to derive the physical properties of high-redshift lensed galaxies, intrinsically fainter than the Lyman break galaxies currently observed in the field. From FORS and ISAAC spectroscopy on the VLT, we use the full rest-frame UV-to-optical range to derive the physical properties (SFR, extinction, chemical abund

J. S. Kaastra, K. C. Steenbrugge, D. M. Crenshaw, S. B. Kraemer

The Seyfert 1 galaxy NGC 5548 was observed for a week by Chandra using both the HETGS and LETGS spectrometers. In this paper we study the time variability of the continuum radiation. During our observation, the source showed a gradual increase in flux over four days, followed by a rapid decrease and flattening of the light curve afterwards. Superimposed upon

V. A. Arefiev, M. G. Revnivtsev, A. A. Lutovinov, R. A. Sunyaev

Results of broadband INTEGRAL and RXTE observations of the Galactic microquasar XTE J1550-564 during outburst in spring 2003 are presented. During the outburst the source was found in a canonical low/hard spectral state.

P. R. Young, A. K. Dupree, B. R. Espey, S. J. Kenyon

Spectra of the bright symbiotic star AG Draconis (BD+67D922) in the wavelength range 905-1187 A obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) are presented. The spectra show a number of narrow, nebular emission lines, together with a uniform continuum from the hot component of the system, and numerous interstellar absorption lines. We infer

Y. -N. Su, S. -Y. Liu, J. Lim, N. Ohashi

We present initial results of an ongoing search for interferometric calibrators at submillimeter (sub-mm) wavelengths with the Submillimeter Array (SMA). Powerful radio galaxies are commonly used as calibrators at centimeter and millimeter wavelengths, but many are not strong enough to serve as calibrators at sub-mm wavelengths because of their rapidly decli

Robert Mach, Frank Schweitzer

Based on experimental observations in \textit{Daphnia}, we introduce an agent-based model for the motion of single and swarms of animals. Each agent is described by a stochastic equation that also considers the conditions for active biological motion. An environmental potential further reflects local conditions for \textit{Daphnia}, such as attraction to lig

Ernest Ma

The A_4 model of leptons was proposed originally for nearly degenerate neutrino masses. With minimal modification, it is shown to accommodate as well the cases of normal hierarchy and inverted hierarchy. In all cases, this new model predicts sin^2 2 theta_{atm} = 1 and tan^2 theta_{sol} = 0.5 for U_{e3} = 0. It also predicts their deviations from 1 and 0.5 r

Laura E. Allen, David Wands

We present a detailed study of a simple scalar field model that yields non-singular cosmological solutions. We study both the qualitative dynamics of the homogeneous and isotropic background and the evolution of inhomogeneous linear perturbations. We calculate the spectrum of perturbations generated on super-Hubble scales during the collapse phase from initi

Sujay K. Ashok, Eleonora Dell&#39;Aquila, Duiliu-Emanuel Diaconescu, Bogdan Florea

We study deformations of Landau-Ginzburg D-branes corresponding to obstructed rational curves on Calabi-Yau threefolds. We determine D-brane moduli spaces and D-brane superpotentials by evaluating higher products up to homotopy in the Landau-Ginzburg orbifold category. For concreteness we work out the details for lines on a perturbed Fermat quintic. In this

Andreas Birkedal, Z. Chacko, Mary K. Gaillard

The current experimental lower bound on the Higgs mass significantly restricts the allowed parameter space in most realistic supersymmetric models, with the consequence that these models exhibit significant fine-tuning. We propose a solution to this `supersymmetric little hierarchy problem&#39;. We consider scenarios where the stop masses are relatively heav

Andrei Mikhailov

Single trace operators with the large R-charge in supersymmetric Yang-Mills theory correspond to the null-surfaces in $AdS_5\times S^5$. We argue that the moduli space of the null-surfaces is the space of contours in the super-Grassmanian parametrizing the complex $(2|2)$-dimensional subspaces of the complex $(4|4)$-dimensional space. The odd coordinates on

Qinghong Cui, Xin Wan, Kun Yang

We present results of numerical studies of spin quantum Hall transitions in disordered superconductors, in which the pairing order parameter breaks time-reversal symmetry. We focus mainly on p-wave superconductors in which one of the spin components is conserved. The transport properties of the system are studied by numerically diagonalizing pairing Hamilton

Olivier Gagnon, Guy D. Moore

We place several new limits on Lorentz violating effects, which can modify particles&#39; dispersion relations, by considering the highest energy cosmic rays observed. Since these are hadrons, this involves considering the partonic content of such cosmic rays. We get a number of bounds on differences in maximum propagation speeds, which are typically bounded

Arjan Keurentjes

When compactifying M- or type II string-theories on tori of indefinite space-time signature, their low energy theories involve sigma models on E_{n(n)}/H_n, where H_n is a not necessarily compact subgroup of E_{n(n)} whose complexification is identical to the complexification of the maximal compact subgroup of E_{n(n)}. We discuss how to compute the group H_

D. Mc Hugh, J. Twamley

Composite pulse sequences designed for nuclear magnetic resonance experiments are currently being applied in many quantum information processing technologies.We present an analysis of a family of composite pulse sequences used to address systematic pulse-length errors in the execution of quantum gates. It has been demonstrated by Cummins et al. [Phys. Rev. A

Alessio D. Romeo, Laura Portinari, Jesper Sommer-Larsen

Cosmological (LambdaCDM) TreeSPH simulations of the formation and evolution of galaxy groups and clusters have been performed. The simulations invoke star formation, chemical evolution with non-instantaneous recycling, metal dependent radiative cooling, strong star burst and (optionally) AGN driven galactic super winds, effects of a meta-galactic UV field an

M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted

We perform a global analysis of all available spin-dependent proton structure function data, covering a large range of Q^2, 1 < Q^2 < 30 GeV^2, and calculate the lowest moment of the g_1 structure function as a function of Q^2. From the Q^2 dependence of the lowest moment we extract matrix elements of twist-4 operators, and determine the color electric and m

E. Arola, M. Horne, P. Strange, H. Winter

A first-principles theory of resonant magnetic scattering of x rays is presented. The scattering amplitudes are calculated using a standard time-dependent perturbation theory to second order in the electron-photon interaction vertex. In order to calculate the cross section reliably an accurate description of the electronic states in the material under invest

A. M. Tsvelik

In this publication I discuss the phase diagram of a frustrated spin-1/2 Heisenberg model suggested in A. A. Nersesyan and A. M. Tsvelik, Phys. Rev. B{\bf 67}, 024422 (2003). The phase diagram contains $(π,0)$ and $(π,π)$ antiferromagnetic phases separated by the Valence Bond Crystal (VBC) state. I argue that the point of the phase diagram with deconfined sp

Peter Minkowski, Wolfgang Ochs

The recent observations of f_0(980) in charmless B-decays motivate further studies of scalar particle and glueball production in these processes. Amplitudes for charmless 2-body B decays involving the members of the scalar nonet are presented based on the symmetries of the dominant penguin contribution. Different scenarios for the lightest scalar nonet are i

Vincent Cachia

We study a classification of the kappa-times integrated semigroups (for kappa>0) by the (uniform) rate of convergence at the origin: $\|S(t)\|=O(t^α)$, $0\leqα\leqκ$. By an improved generation theorem we characterize this behaviour by Hille-Yosida type estimates. Then we consider integrated semigroups with holomorphic extension and characterize the convergen

Constantin V. Usenko, Vladyslav C. Usenko

This work is the development and analysis of the recently proposed quantum cryptographic protocol, based on the use of the two-mode coherently correlated states. The protocol is supplied with the cryptographic control procedures. The quantum noise influence on the channel error properties is examined. State detection features are proposed.

G. Duplancic, H. Pasagic, J. Trampetic

The ${\bf 27}_{J=3/2}$-plet mass spectrum and the ${\bf 27}_{3/2}$-$\bar{\bf 10}$ mass splittings are computed in the framework of the minimal SU(3)$_f$ extended Skyrme model. As functions of the Skyrme charge $e$ and the SU(3)$_f$ symmetry breaking parameters the predictions are presented in tabular form. The predicted mass splitting ${\bf 27}_{3/2}$-$\bar{

Zhi Zhao, An-Ning Zhang, Yu-Ao Chen, Han Zhang

Universal logic gates for two quantum bits (qubits) form an essential ingredient of quantum information processing. However, the photons, one of the best candidates for qubits, suffer from the lack of strong nonlinear coupling required for quantum logic operations. Here we show how this drawback can be overcome by reporting a proof-of-principle experimental

Wen-Tai Chiang, B. Saghai, F. Tabakin, T. -S. H. Lee

The pi N --> KY and KY --> KY reactions are studied using a dynamical coupled-channel model of meson-baryon interactions at energies where the baryon resonances are strongly excited. The channels included are: pi N, K Λ, and KΣ. The resonances considered are: N^* [S_{11}(1650), P_{11}(1710), P_{13}(1720),D_{13}(1700)]; Δ^* [S_{31}(1900), P_{31}(1910), P_{33}

Andrew W. Blain, Scott C. Chapman, Ian Smail, Rob Ivison

The spectral energy distributions (SEDs) of dust-enshrouded galaxies with powerful restframe far-infrared emission have been constrained by a range of ground-based and space-borne surveys. The IRAS catalog provides a reasonably complete picture of the dust emission from nearby galaxies (at redshifts of order 0.1) that are typically less luminous than about 1

Uri Bader, Uri Onn

We study a family of complex representations of the group GL(n,O), where O is the ring of integers of a non-archimedean local field F. These representations occur in the restriction of the Grassmann representation of GL(n,F) to its maximal compact subgroup GL(n,O). We compute explicitly the transition matrix between a geometric basis of the Hecke algebra ass

Masato Minamitsuji, Misao Sasaki

We investigate the linearized gravity on a single de Sitter brane in the anti-de Sitter (AdS) bulk in the Einstein Gauss-Bonnet (EGB) theory. We find that the Einstein gravity is recovered for a high energy brane, i.e., in the limit of the large expansion rate, $H\ell\gg 1$, where $H$ is the de Sitter expansion rate and $\ell$ is the curvature radius of the

Won Tae Kim, Edwin J. Son

We show that the RST model describing the exactly soluble black hole model can have a dynamical wormhole solution along with an appropriate boundary condition. The necessary exotic matter which is usually negative energy density is remarkably produced by the quantization of the infalling matter fields. Then the asymptotic geometry in the past is two-dimensio

Alain Bérard, Herve Mohrbach

We consider the adiabatic evolution of the Dirac equation in order to compute its Berry curvature in momentum space. It is found that the position operator acquires an anomalous contribution due to the non Abelian Berry gauge connection making the quantum mechanic algebra noncommutative. A generalization to any known spinning particles is possible by using t

K. Slevin, Y. Asada, L. I. Deych

We report a numerical investigation of the fluctuations of the Lyapunov exponent of a two dimensional non-interacting disordered system. While the ratio of the mean to the variance of the Lyapunov exponent is not constant, as it is in one dimension, its variation is consistent with the single parameter scaling hypothesis.

Shun Zhou, Zhi-zhong Xing

We present a systematic study of 400 combinations of the charged lepton and neutrino mass matrices with six vanishing entries or texture zeros. Only 24 of them, which can be classified into a few distinct categories, are found to be compatible with current neutrino oscillation data at the $3σ$ level. A peculiar feature of the lepton mass matrices in each cat

S. V. Bulanov, T. Esirkepov, P. Migliozzi, F. Pegoraro

A new mechanism is suggested for efficient proton acceleration in the GeV energy range; applications to non-conventional high intensity proton drivers and, hence, to low-energy (10-200 MeV) neutrino sources are discussed. In particular we investigate possible uses to explore subdominant $\barν_μ\to \barν_e$ oscillations at the atmospheric scale and their CP

V. Sauli

The new method of solution of the Bethe-Salpeter equation for quark-antiquark pseudoscalar bound state is proposed. With the help of integral representation the results are directly obtained in Minkowski space. Dressing of Greens functions is naturally considered providing thus the correct inclusion of the running coupling constant and the quark propagators

Piotr W. Nowak

We prove a geometric characterization of a-T-menability through proper, affine, isometric actions on the Banach spaces $L_p[0,1]$ for $1<p<2$. This answers a question of A. Valette.

Qingshan Yuan, Yan Chen, T. K. Lee, C. S. Ting

By use of the slave-boson mean-field approach, we have studied the electron-doped t-t&#39;-t&#39;&#39;-J model in the antiferromagnetic (AF) state. It is found that at low doping the Fermi surface (FS) pockets appear around $(\pmπ,0)$ and $(0,\pmπ)$, and upon increasing doping the other ones will form around $(\pm{π\over 2},\pm{π\over 2})$. The evolution of

Oliver Passon

In the spirit and style of John S. Bell&#39;s well known paper on How to Teach Special Relativity it is argued, that a ``Bohmian pedagogy&#39;&#39;provides a very useful tool to illustrate the relation between classical and quantum physics and illuminates the peculiar features of the latter.

James F. Gillooly, Andrew P. Allen, Geoffrey B. West, James H. Brown

Observations that rates of molecular evolution vary widely within and among lineages have cast doubts upon the existence of a single molecular clock. Differences in the timing of evolutionary events estimated from genetic and fossil evidence have raised further questions about the existence of molecular clocks and their use. Here we present a model of nucleo

Byung Mook Weon

Are there limits to human longevity? We suggest a new demographic model to describe human demographic trajectories. Specifically, the model mathematically defines the limits of longevity. Through the demographic analysis of trends for Sweden (between 1751 and 2002), Switzerland (between 1876 and 2002) and Japan (between 1950 and 1999), which are the longest-

Byung Mook Weon

The Gompertz model since 1825 has significantly contributed to interpretation of ageing in biological and social sciences. However, in modern research findings, it is clear that the Gompertz model is not successful to describe the whole demographic trajectories. In this letter, a new demographic model is introduced especially to describe human demographic tr

Sergey Kurennoy, Dale Schrage, Richard Wood, Tom Schultheiss

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. A preliminary design of a normal-conducting, 2.5-cell pi-mode, 700-MHz CW RF photoinjector that will be built for demonstration purposes, is completed. This photoinjector will be capable of accelerating a 100-mA electron beam (3 nC per bunch at 35 MHz

Daniel Livescu, Cyrus K. Madnia

The structure of homogeneous turbulent shear flow is studied using data generated by Direct Numerical Simulations (DNS) and a linear analysis for both compressible and incompressible cases. At large values of the mean shear rate, the Rapid Distortion Theory (RDT) limit is approached. Analytical solutions are found for the inviscid compressible RDT equations

N. M. Chase

Integer partitions are deeply related to many phenomena in statistical physics. A question naturally arises which is of interest to physics both on &#34;purely&#34; theoretical and on practical, computational grounds. Is it possible to apprehend the global pattern underlying integer partition sequences and to express the global pattern compactly, in the form

O. Busch

We present measurements of the transition radiation (TR) spectrum produced in an irregular radiator at different electron momenta. The data are compared to simulations of TR from a regular radiator.

Young-Gu Ju

A very simple and efficient evaluation procedure is suggested for the design of high power single mode VCSELs by reviewing the physical mechanisms that governs mode transition and simplifying the computation steps. In addition, the new structures are proposed and tested following the suggested evaluation procedure. As a result, the proposed design exhibits m

Rudolph C. Hwa, C. B. Yang

Proton production in the intermediate p_T region in d+Au collisions is studied in the parton recombination model. The recombination of soft and shower partons is shown to be important in central collisions, but negligible in peripheral collisions. It is found that the large nuclear modification factor for proton production can be well reproduced by a calcula

Denes Molnar, Pasi Huovinen

We compare elliptic flow evolution from ideal hydrodynamics and covariant parton transport theory, and show that, for conditions expected at RHIC, dissipation significantly reduces elliptic flow even for extreme parton cross sections and/or densities sigma_gg * dN/dη(b=0) ~ 45 mb * 1000. The difference between transport and hydrodynamic elliptic flow is esta

L. Tolos, J. Schaffner-Bielich, A. Mishra

The spectral density of the $D$-meson in the nuclear environment is studied within a self-consistent coupled-channel approach assuming a separable potential for the bare meson-baryon interaction. The $DN$ interaction, described through a G-matrix, generates dynamically the $Λ_c$ (2593) resonance. This resonance is the charm counterpart of the $Λ$ (1405) reso

Yoshifumi R. Shimizu, Masayuki Matsuzaki, Kenichi Matsuyanagi

One of the most striking findings in the recent high-spin spectroscopy is the discovery of one-phonon, and possibly double-phonon, excitation of the nuclear wobbling rotational bands. In this talk, we first review the properties of observed wobbling motions, and discuss the failure and success of the possible interpretation in terms of the simple rotor model

L. S. Barnby

We present transverse momentum spectra from d+Au collisions at sqrt(s_NN) = 200 GeV for identified hadrons at mid-rapidity and unidentified hadrons in the forward rapidity region using the Solenoidal Tracker at RHIC. We scale these spectra by the mean number of binary collisions to form a transverse momentum dependent ratio to spectra from p+p collisions, sh

K. Sekiguchi, H. Sakai, H. Witała, K. Ermisch

The deuteron to proton polarization transfer coefficients for the $d$--$p$ elastic scattering were precisely measured with an incoming deuteron energy of 135 MeV/u at the RIKEN Accelerator Research Facility. The data are compared to theoretical predictions based on exact solutions of three-nucleon Faddeev equations with high--precision nucleon--nucleon force

W. Trautmann, A. Le Fevre, J. Lukasik

With INDRA at GSI, multifragmentation was studied in 197Au + 197Au reactions at bombarding energies 40 to 150 MeV per nucleon. The mechanisms of fragment production at mid-rapidity in peripheral collisions and the interplay of collective motion and fragmentation in central collisions were investigated. The balance energy for squeeze-out, i.e. the transition

V. E. Vekslerchik

The Backlund transformations for the Nizhnik-Novikov-Veselov equation are presented. It is shown that these transformations can be iterated and that the resulting sequence can be described by the Volterra equations. The relationships between the Nizhnik-Novikov-Veselov equation and the Volterra hierarchy are discussed.

N. M. Chase

A recent paper examined the global structure of integer partitions sequences and, via combinatorial analysis using modular arithmetic, derived a closed form expression for a map from (N, M) to the set of all partitions of a positive integer N into exactly M positive integer summands. The output of the IPS map was a &#34;matrix&#34; having M columns and a num

Jan Philip Solovej

We prove the ionization conjecture within the Hartree-Fock theory of atoms. More precisely, we prove that, if the nuclear charge is allowed to tend to infinity, the maximal negative ionization charge and the ionization energy of atoms nevertheless remain bounded. Moreover, we show that in Hartree-Fock theory the radius of an atom (properly defined) is bounde

Alexander M. Meadows

We study properties of the semilinear elliptic equation $Δu = 1/u$ on domains in $R^n$, with an eye toward nonnegative singular solutions as limits of positive smooth solutions. We prove the nonexistence of such solutions in low dimensions when we also require them to be stable for the corresponding variational problem. The problem of finding singular soluti

Arnold W. Miller

We show that the continuum hypothesis implies there exists a Lindelof space X such that X x X is the union of two metrizable subspaces but X is not metrizable. This gives a consistent solution to a problem of Balogh, Gruenhage, and Tkachuk. The main lemma is that assuming the continuum hypothesis there exist disjoint sets of reals X and Y such that X is Bore

Elena Rubei

This paper deals with syzygies of Segre embeddings. Let d >=3 and n_1, ..., n_d nonzero natural numbers. We prove that O(1,...., 1) on the product of P^{n_1}, ...,P^{n_d} satisfies Property N_p if and only if p <= 3.

Simon Brendle

We study a higher-order parabolic equation which generalizes the Ricci flow on two-dimensional surfaces. The metric is deformed conformally with a speed given by the Q-curvature of the metric. Under a condition on the Q-curvature of the initial metric we show that the soluton exists for all time and converges to a metric of prescribed Q-curvature.

Joseph H. Silverman

For a given point P in the group of K-rational points E(K) of an elliptic curve, we consider the sequence of values (F_1(P),F_2(P),F_3(P),...) of the division polynomials of E at P. If K is a finite field, we prove that the sequence is periodic. If K/Q_p is a local field, we prove (under certain hypotheses) that there is a power q=p^e so that for all m > 0,

Nondas E. Kechagias

This work deals with Adem relations in the Dyer-Lashof algebra from a modular invariant point of view. The main result is to provide an algorithm which has two effects: Firstly, to calculate the hom-dual of an element in the Dyer-Lashof algebra; and secondly, to find the image of a non-admissible element after applying Adem relations. The advantage of our me

Liana David, Ian A. B. Strachan

Given a flat metric one may generate a local Hamiltonian structure via the fundamental result of Dubrovin and Novikov. More generally, a flat pencil of metrics will generate a local bi-Hamiltonian structure, and with additional quasi-homogeneity conditions one obtains the structure of a Frobenius manifold. With appropriate curvature conditions one may define

Vincent Cachia

For any nonnegative self-adjoint operators A and B in a separable Hilbert space, we show that the Trotter-type formula $[(e^{i2tA/n}+e^{i2tB/n})/2]^n$ converges strongly in the closure of the intersection of the domains of A^{1/2} and B^{1/2}, along some subsequence and for almost every real number t. This result extends to the degenerate case and to Kato-fu

Ignasi Mundet i Riera, Gang Tian

We construct a compactification of the moduli space of twisted holomorphic maps with varying complex structure and bounded energy. For a given compact symplectic manifold $X$ with a compatible complex structure and a Hamiltonian action of $S^1$ with moment map $μ:X\to\imag\RR$, the moduli space which we compactify consists of equivalence classes of tuples $(

Stephan Hell

We give an extension of the lower bound of Vucic and Zivaljevic for the number of Tverberg partitions from the prime to the prime power case. Our proof is inspired by the Z_p-index version of the proof in Matousek&#39;s book &#34;Using the Borsuk-Ulam Theorem&#34; and uses Volovikov&#39;s Lemma. Analogously, one obtains an extension of the lower bound for th

Maurizio Cailotto

In this paper we present the notion of ``Deligne localized functors&#39;&#39;, an avatar of the derived functors, whose definition is inspired by Deligne in [SGA 4,XVII]. Their definition involves the notions of Ind and Pro categories, they always exist and are characterized in terms of universal properties. The classical localized functor, in the sense of G

Azat Ainouline

Whitney type examples of maps $f\in C^k(\real^m,\real^n)$ for a maximal possible real $k$, and multidimensional space-filling curves with special properties are constructed.

Jae Choon Cha

We characterize the Murasugi polynomial of an equivariant slice knot by proving a conjecture of J. Davis and S. Naik.

Piotr W. Nowak

There are several characterizations of coarse embeddability of a discrete metric space into a Hilbert space. In this note we give such characterizations for general metric spaces. By applying these results to the spaces $L_p(μ)$, we get their coarse embeddability into a Hilbert space for $0<p<2$. This together with a theorem by Banach and Mazur yields that c

I. V. Krasovsky

We obtain uniform asymptotics for polynomials orthogonal on a fixed and varying arc of the unit circle with a positive analytic weight function. We also complete the proof of the large $s$ asymptotic expansion for the Fredholm determinant with the kernel $\sin z/(πz)$ on the interval $[0,s]$, verifying a conjecture of Dyson for the constant term in the expan

Pietro Corvaja, Umberto Zannier

Let $Γ$ be a finitely generated subgroup of the multiplicative group $\G_m^2(\bar{Q})$. Let $p(X,Y),q(X,Y)\in\bat{Q}$ be two coprime polynomials not both vanishing at $(0,0)$; let $ε>0$. We prove that, for all $(u,v)\inΓ$ outside a proper Zariski closed subset of $G_m^2$, the height of $p(u,v)/q(u,v)$ verifies $h(p(u,v)/q(u,v))>h(1:p(u,v):q(u,v))-ε\max(h(uu)

David Hernandez

The q-characters were introduced by Frenkel and mReshetikhin to study finite dimensional representations of the untwisted quantum affine algebra for q generic. The $ε$-characters at roots of unity were constructed by Frenkel and Mukhin to study finite dimensional representations of various specializations of the quantum affine algebra at $q^s=1$. In the fini

G. Papadopoulos

We extend the definition of the Szekeres-Iyer power-law singularities to supergravity, string and M-theory backgrounds, and find that are characterized by Kasner type exponents. The near singularity geometries of brane and some intersecting brane backgrounds are investigated and the exponents are computed. The Penrose limits of some of these power-law singul

Ali H. Chamseddine, Mikhail S. Volkov

We present a family of globally regular ${\cal N}=1$ vacua in the D=4, ${\cal N}=4$ gauged supergravity of Gates and Zwiebach. These solutions are labeled by the ratio $ξ$ of the two gauge couplings, and for $ξ=0$ they reduce to the supergravity monopole previously used for constructing the gravity dual of ${\cal N}=1$ super Yang-Mills theory. For $ξ>0$ the

O. S. Ventura, R. L. P. G. Amaral, J. V. Costa, L. O. Buffon

We present a class of mappings between the fields of the Cremmer-Sherk and pure BF models in 4D. These mappings are established by two distinct procedures. First a mapping of their actions is produced iteratively resulting in an expansion of the fields of one model in terms of progressively higher derivatives of the other model fields. Secondly an exact mapp

Wilfried Buchmuller, Koichi Hamaguchi, Oleg Lebedev, Michael Ratz

Many compactifications of higher-dimensional supersymmetric theories have approximate vacuum degeneracy. The associated moduli fields are stabilized by non-perturbative effects which break supersymmetry. We show that at finite temperature the effective potential of the dilaton acquires a negative linear term. This destabilizes all moduli fields at sufficient

Zhiyi Liu, Benhao Sa, Shuhua Zhou

Hadron and string cascade model (JPCIAE) with the hypothesis without introducing the quark-gluon plasma (QGP), is employed to study the direct photon and $π^0$ transverse momentum distributions for central $^{208}$Pb+$^{208}$Pb collisions at 158A GeV/c . JPCIAE model, is based on LUND model, especially on the envent generator PYTHIA, and can be used to simul

J. R. Forshaw, R. Sandapen, G. Shaw

We confront the colour glass condensate motivated dipole model parameterization of Iancu, Itakura and Munier with the available HERA data on the diffractive structure function F2D3 and with existing dipole model parameterizations. Reasonably good agreement is found with only two adjustable parameters. We caution against interpreting the success of the model

V. Bashiry

The lepton polarization asymmetry in the B\to\ell^{+}\ell^{-} decay, when one of the leptons is polarized, is investigated using the most general form of the effective Hamiltonian. The sensitivity of the asymmetry to the new Wilson coefficients is studied.Moreover, correlations between the lepton polarization asymmetry and the branching ratio is studied. It

Chris Quigg

To illustrate the campaign to understand heavy quarkonium systems, I focus on a puzzling new state, $X(3872) \to π^+π^- J/ψ$. Studying the influence of open-charm channels on charmonium properties leads us to propose a new charmonium spectroscopy: additional discrete charmonium levels that can be discovered as narrow resonances of charmed and anticharmed mes

Carl Lundstedt, Dan Claes

Using 85.2 +/- 3.6 pb^-1 of p-pbar collisions collected at sqrt(s)=1.8 TeV with the D0 detector at Fermilab&#39;s Tevatron Collider, we present the results of a search for direct pair production of scalar top quarks ~t, the supersymmetric partners of the top quark. We examined events containing two or more jets and missing transverse energy, the signature of

Edward Anderson, Julian Barbour, Brendan Z. Foster, Bryan Kelleher

The only efficient and robust method of generating consistent initial data in general relativity is the conformal technique initiated by Lichnerowicz and perfected by York. In the spatially compact case, the complete scheme consists of the Arnowitt-Deser-Misner (ADM) Hamiltonian and momentum constraints, the ADM Euler-Lagrange equations, York&#39;s constant-

Gianluca Argentini

In this work I present a technique of construction and fast evaluation of a family of cubic polynomials for analytic smoothing and graphical rendering of particles trajectories for flows in a generic geometry. The principal result of the work was implementation and test of a method for interpolating 3D points by regular parametric curves and their fast and e

Sanjay Rana, Mike Batty

This paper proposes the application of some well known two-dimensional geometrical shape descriptors for the visualisation of the structure of architectural open spaces. The paper demonstrates the use of visibility measures such as distance to obstacles and amount of visible space to calculate shape descriptors such as convexity and skeleton of the open spac

Xiaoyang Gu

In this paper, we use resource-bounded dimension theory to investigate polynomial size circuits. We show that for every $i\geq 0$, $\Ppoly$ has $i$th order scaled $\pthree$-strong dimension 0. We also show that $\Ppoly^\io$ has $\pthree$-dimension 1/2, $\pthree$-strong dimension 1. Our results improve previous measure results of Lutz (1992) and dimension res

W. Ali, R. J. Mondragon, F. Alavi

Different classes of communication network topologies and their representation in the form of adjacency matrix and its eigenvalues are presented. A self-organizing feature map neural network is used to map different classes of communication network topological patterns. The neural network simulation results are reported.

Danilo Gligoroski

In this paper we design a stream cipher that uses the algebraic structure of the multiplicative group $\bbbz_p^*$ (where p is a big prime number used in ElGamal algorithm), by defining a quasigroup of order $p-1$ and by doing quasigroup string transformations. The cryptographical strength of the proposed stream cipher is based on the fact that breaking it wo

Ryota Sato, Takuma Ohashi, Akihisa Koga, Norio Kawakami

We investigate a multi-orbital extension of the periodic Anderson model with particular emphasis on electron correlations including orbital fluctuations. By means of a linearized version of the dynamical mean-field theory, we compute the renormalization factor, the density of states, the spectral gap and the local correlation functions for a given set of the

Alba Theumann, B. Coqblin

The Kondo-Spin Glass competition is studied in a theoretical model of a Kondo lattice with an intra-site Kondo type exchange interaction treated within the mean field approximation, an inter-site quantum Ising exchange interaction with random couplings among localized spins and an additional transverse field in the x direction, which represents a simple quan

Dmitri V. Averin, Alexander N. Korotkov

This is a comment on recent paper by T.M. Stace and S.D. Barrett, PRL 92, 136802 (2004). We show that the main result of the paper, absence of the spectral peak for continuous weak measurement of coherent oscillations in a qubit, is incorrect.

J. Hassel, H. Seppa

The Bloch oscillating transistor (BOT) is a device, where single electron current through a normal tunnel junction can be used to enhance Cooper pair current in a mesoscopic Josephson junction leading to signal amplification. In this paper we develop a theory, where the BOT dynamics is described as a two-level system. The theory is used to predict current-vo

R. Khasanov, D. G. Eshchenko, J. Karpinski, S. M. Kazakov

We report magnetization measurements under high hydrostatic pressure in the newly discovered pyrochlore superconductor RbOs_2O_6 (T_c\simeq6.3K at p=0). A pronounced and {\it positive} pressure effect (PE) on T_c with dT_c/dp =0.090(1)K/kbar was observed, whereas no PE on the magnetic penetration depth λwas detected. The relative pressure shift of T_c [ dlnT

Pascal Simon, Rosa Lopez, Yuval Oreg

We investigate theoretically the transport properties of two independent artificial Kondo impurities. They are coupled together via a tunable Ruderman-Kittel-Kasuya-Yoshida (RKKY) interaction. For strong enough antiferromagnetic RKKY interaction, the impurity density of states increases with the applied in-plane magnetic field. This effect can be used to dis

V. P. Mineev

The transport equation for transverse vibrations of magnetization in spin polarized Fermi liquid is derived from integral equation for the vertex function. The dispersion law for the transverse spin waves is established. The existance of zero-temperature spin-waves attenuation is confirmed. The problem of similar derivation in ferromagnetic &#34;Fermi liquid

Sz. Csonka, A. Halbritter, G. Mihaly, O. I. Shklyarevskii

Results of an experimental study of palladium nanojunctions in hydrogen environment are presented. Two new hydrogen-related atomic configurations are found, which have a conductances of ~0.5 and ~1 quantum unit (2e^2/h). Phonon spectrum measurements demonstrate that these configurations are situated between electrodes containing dissolved hydrogen. The cruci