June 2001 arXiv papers — page 9

J. Mueller-Quade, H. Imai

This paper introduces quantum multiparty protocols which allow the use of temporary assumptions. We prove that secure quantum multiparty computations are possible if and only if classical multi party computations work. But these strict assumptions are necessary only during the execution of the protocol and can be loosened after termination of the protocol. W

A. I. Arbab

We have proposed a model to obtain the length of the day and month at any geologic time. The day is found to increase by 0.002 sec/century since the seventeenth century. The lengthening of the day is attributed entirely to the increasing gravitational constant ($G$) with time that manifested its self in tidal forces. The data obtained are consistent with tho

Wei-Mou Zheng

The primitive data for deducing the Miyazawa-Jernigan contact energy or BLOSUM score metrix are the pair frequency counts. Each amino acid corresponds to a distribution. Taking the Kullback-Leibler distance of two probability distributions as resemblance coefficient and relating cluster to mixed population, we perform cluster analysis of amino acids based on

Bruno Macke, Bernard Segard

The mechanisms leading to a seemingly superluminal propagation of light in dispersive media are examined. The anomalous dispersion near an absorption line, involved in the first experiments displaying negative group velocity propagation, is shown to be not only simpler but also more efficient than the so-called transparent dispersion used in the later experi

H. R. Pang, J. L. Ping, Fan Wang, T. Goldman

We present a phenomenological study of three models with different effective degrees of freedom: a Goldstone Boson Exchange (GBE) model which is based on quark-meson couplings, the quark delocalization, color screening model (QDCSM) which is based on quark-gluon couplings with delocalized quark wavefunctions, and the Fujiwara-Nijmegen (FN) mixed model which

A. Parreno, A. Ramos, C. Bennhold

The strangeness-changing ($ΔS = 1$) weak baryon-baryon interaction is studied through the nonmesonic weak decay of double-$Λ$ hypernuclei. Besides the usual nucleon-induced decay $ΛN \to N N$ we discuss novel hyperon-induced decay modes $ΛΛ\to ΛN$ and $ΛΛ\to ΣN$. These reactions provide unique access to the exotic $ΛΛ$K and $ΛΣ$K vertices which place new con

Agnieszka Bieniek, Anna Baran, Wojciech Broniowski

We calculate the medium modification of the pi-omega-rho vertex and analyze its significance for the pi^0 -> gamma gamma*, omega -> pi^0 gamma*, and rho -> pi gamma* decays in nuclear matter. We use a relativistic hadronic approach at zero temperature and in the leading-density limit, and consider decays of particles at rest with respect to the medium. It is

B. Pfeiffer, K. -L. Kratz, P. Moeller

We present in this paper a compilation of the present status of experimental delayed-neutron precursor data; i.e. beta-decay half-lives (T_1/2) and neutron emission probabilities (P_n) in the fission-product region (27 <= Z <= 57). These data are compared to two model predictions of substantially different sophistication: (i) an update of the empirical Kratz

P. A. Braun, F. Haake, S. Heusler

Recently, Sieber and Richter calculated semiclassically a first off-diagonal contribution to the orthogonal form factor for a billiard on a surface of constant negative curvature by considering orbit pairs having almost the same action. For a generalization of this derivation to systems invariant under non-conventional time reversal symmetry, which also belo

Vestislav Apostolov, John Armstrong, Tedi Draghici

We show that any non-Kahler, almost Kahler 4-manifold for which both the Ricci and the Weyl curvatures have the same algebraic symmetries as they have for a Kahler metric is locally isometric to the (only) proper 3-symmetric 4-dimensional space described by O. Kowalski.

Roland Auer, Jaap Top

We show that every elliptic curve over a finite field of odd characteristic whose number of rational points is divisible by 4 is isogenous to an elliptic curve in Legendre form, with the sole exception of a minimal respectively maximal elliptic curve. We also collect some results concerning the supersingular Legendre parameters.

Yanguang Charles Li

Existence of homoclinic orbits in the cubic nonlinear Schrödinger equation under singular perturbations is proved. Emphasis is placed upon the regularity of the semigroup $e^{\e t \pa_x^2}$ at $\e = 0$. This article is a substantial generalization of \cite{LMSW96}, and motivated by the effort of Dr. Zeng \cite{Zen00a} \cite{Zen00b}. The mistake of Zeng in \c

Kiran S. Kedlaya

Building on our previous papers (math.AG/0102173, math.AG/0105244, math.AG/0106192) we prove that every overconvergent F-isocrystal over k((t)) is quasi-unipotent (in the sense of Crew), for k a field of positive characteristic.

Kiran S. Kedlaya

R. Crew conjectured that every overconvergent F-isocrystal over k((t)) (k a field of positive characteristic) is quasi-unipotent (equivalently, potentially semistable), and so has ``generic&#39;&#39; and ``special&#39;&#39; Newton polygons. It is easy to construct a Newton polygon for an arbitrary overconvergent F-crystal that coincides with the generic Newt

F. Hivert, A. Lascoux, J. -Y. Thibon

We define two-parameter families of noncommutative symmetric functions and quasi-symmetric functions, which appear to be the proper analogues of the Macdonald symmetric functions in these settings.

Mireille Martin-Deschamps

This paper is the text of a lecture given at the Catania conference on Commutative Algebra and Algebraic Geometry, in honor of the 60th birthday of Silvio Greco. It analyses the correspondences between equivalence classes of objects related to the projective 3-space ${\bf P}^3_k$ over a field $k$ : - vector bundles ${\cal F}$ such that $H_*^2({\cal F})=0$ up

Ruth Charney, Alexander Lytchak

A building is a simplicial complex with a covering by Coxeter complexes (called apartments) satisfying certain combinatorial conditions. A building whose apartments are spherical (respectively Euclidean) Coxeter complexes has a natural piecewise spherical (respectively Euclidean) metric with nice geometric properties. We show that spherical and Euclidean bui

Stipsicz, Andras I

We determine topological properties of Stein domains with boundary diffeomorphic to T^3, S^1\times S^2 and some Seifert fibered 3-manifolds.

Anna Maria Pelczar

We show that every Banach space saturated with subsymmetric sequences contains a minimal subspace.

Eva Silverstein

I present asymmetric orientifold models which, with the addition of RR fluxes, fix all the NS NS moduli including the dilaton. In critical string theory, this gives new AdS backgrounds with (discretely tunably) weak string coupling. Extrapolating to super-critical string theory, this construction leads to a promising candidate for a metastable de Sitter back

M. Lubo

Apart from the flat space with an angular deficit, Einstein general relativity possesses another cylindrically symmetric solution. Because this configuration displays circles whose &#34;circumferences&#34; tend to zero when their &#34;radius&#34; go to infinity, it has not received much attention in the past. We propose a geometric interpretation of this fea

Rafael I. Nepomechie

We construct an action for the N=2 supersymmetric sine-Gordon model on the half-line, which we argue is both supersymmetric and integrable. The boundary interaction depends on three continuous boundary parameters, as well as the bulk mass parameter.

Krzysztof A. Meissner, Marek Olechowski

We consider a class of higher order corrections in the form of Euler densities of arbitrary rank $n$ to the standard gravity action in $D$ dimensions. We have previously shown that this class of corrections allows for domain wall solutions despite the presence of higher powers of the curvature. In the present paper we explicitly solve the linearized equation

Machiko Hatsuda, Kiyoshi Kamimura

We analyze the anti-de Sitter (AdS) superparticle and superstring systems described in terms of supermatrix valued coordinates proposed by Roiban and Siegel. This approach gives simple symmetry transformations and equations of motion. We examine their kappa-transformations, infinite reducibility and kappa-gauge fixing conditions. A closed first class constra

M. Anselmino, M. Boglione, U. D&#39;Alesio, F. Murgia

We calculate, within pQCD parton model at leading orders, the expression of the longitudinal polarization of Lambda baryons produced in polarized semi-inclusive DIS, including weak interaction effects. We present some numerical estimates in few cases for which data are or will soon be available and discuss how to gather new information on polarized fragmenta

M. Anselmino, D. Boer, U. D&#39;Alesio, F. Murgia

The long-standing problem of transverse Lambda polarization in high-energy collisions of unpolarized hadrons can be tackled by considering new, spin and k_T-dependent quark fragmentation functions for an unpolarized quark into a polarized, spin-1/2 hadron. Simple phenomenological parameterizations of these new &#34;polarizing fragmentation functions&#34;, wh

Tommaso Tabarelli de Fatis

MONOLITH is a proposed massive magnetized tracking calorimeter at the Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon neutrinos. The main goal is to test the neutrino oscillation hypothesis through an explicit observation of the full first oscillation swing. The sensitivity range for this measurement comfortably covers the ent

Sang Pyo Kim

The effective theory of an open boson or fermion system is studied, which evolves out of equilibrium with time-dependent Hamiltonian $\hat{H}(t)$. A measure of nonequilibrium temperature for the open system evolving from an equilibrium is proposed as the time-averaged energy expectation value $T(t) = T_i(\bar{< \hat{H} (t) >_Ψ}/ \bar{< \hat{I} (t) >_Ψ})$, wh

Stephen Rock

The nucleon electromagnetic form factors G_E and G_M are complex quantities in the time-like region. The absolute values can be determined by measuring the angular distribution of the nucleons in e^+ e^- --> N N-bar. The complex phase can only be determined by measuring one or more polarizations of the initial or final state. For PEP-N, we can use unpolarize

R. Ducar, J. Hylen, V. Garkusha, C. Jensen

The Neutrinos at the Main Injector (NuMI) beam supplies an intense $ν_μ$ beam to the Main Injector Neutrino Oscillation Search (MINOS). The $ν_μ$&#39;s are derived from a secondary $π^+$ beam that is allowed to decay within a 675 m decay tunnel. As part of this effort, we are developing a continuous toroidal magnetic focusing system, called the Hadronic Hose

S. Sultansoy, A. K. Ciftci, E. Recepoglu, O. Yavas

Options for future $lepton-proton,lepton-nucleus,γ-proton,γ-nucleus$ and FEL$γ-nucleus$ colliders are discussed. In the spirit of this content, we consider TESLAxHERA, LEPxLHC, $μ$xTEVATRON, exRHIC, LinacxLHC, $\sqrt{s}=3TeV$ $μp$ and CLIC based colliders.

S. E. S. Schagen

We present measurements of charm production in DIS using the ZEUS detector. Data with an integrated luminosity of 83 pb$^{-1}$ have been analysed. For the channel $D^{*+} \to D^{0}π_{s}^{+} \to K^{-}π^{+}π_{s}^{+} (+ c.c.)$ a cross section has been extracted, differential in the kinematical variables $Q^{2}$ and Bjorken $x$. In addition the decay $\overline{

L. Favart

Results on Deeply Virtual Compton Scattering at HERA measured by the H1 and ZEUS Collaborations are presented. The cross section, measured for the first time, is reported for $Q^2 > 2 GeV^2$, $30 < W < 120 GeV$ and $|t| < 1 GeV^2$.

Johannes Ruoff, Kostas D. Kokkotas

We consider both mode calculations and time evolutions of axial r-modes for relativistic uniformly rotating non-barotropic neutron stars, using the slow-rotation formalism, in which rotational corrections are considered up to linear order in the angular velocity Ω. We study various stellar models, such as uniform density models, polytropic models with differ

J. Mueller-Quade, H. Imai

With oblivious transfer multiparty protocols become possible even in the presence of a faulty majority. But all known protocols can be aborted by just one disruptor. This paper presents more robust solutions for multiparty protocols with oblivious transfer. This additional robustness against disruptors weakens the security of the protocol and the guarantee t

O. O. Bernal, C. Rodrigues, A. Martinez, H. G. Lukefahr

We present new 29-Si NMR spectra in URu2Si2 for varying temperature T, and external field H. On lowering T, the systematics of the low-field lineshape and width reveal an extra component (lambda) to the linewidth below T_N ~ 17 K not observed previously. We find that lambda is magnetic-field independent and dominates the low-field lineshape for all orientati

Alain Rochefort, Massimiliano Di Ventra, Phaedon Avouris

We investigate theoretically the switching characteristics of semiconducting carbon nanotubes connected to gold electrodes under an external (gate) electric field. We find that the external introduction of holes is necessary to account for the experimental observations. We identify metal-induced-gap states (MIGS) at the contacts and find that the MIGS of an

Peter Sollich

Learning curves for Gaussian process regression are well understood when the `student&#39; model happens to match the `teacher&#39; (true data generation process). I derive approximations to the learning curves for the more generic case of mismatched models, and find very rich behaviour: For large input space dimensionality, where the results become exact, t

A. R. Goñi, U. Haboeck, C. Thomsen, K. Eberl

A two-dimensional (2D) electron gas formed in a modulation-doped GaAs/AlGaAs single quantum well undergoes a first-order transition when the first excited subband is occupied with electrons, as the Fermi level is tuned into resonance with the excited subband by applying a dc voltage. Direct evidence for this effect is obtained from low-temperature photolumin

A. Dorneich, M. Troyer

The Stochastic Series Expansion method (SSE) is a Quantum Monte Carlo (QMC) technique working directly in the imaginary time continuum and thus avoiding &#34;Trotter discretization&#34; errors. Using a non-local &#34;operator-loop update&#34; it allows treating large quantum mechanical systems of many thousand sites. In this paper we first give a comprehensi

R. Folk, Yu. Holovatch, T. Yavors&#39;kii

We discuss universal and non-universal critical exponents of a three dimensional Ising system in the presence of weak quenched disorder. Both experimental, computational, and theoretical results are reviewed. Special attention is paid to the results obtained by the field theoretical renormalization group approach. Different renormalization schemes are consid

Bumsoo Kyung

In this paper we show that local spin-singlet amplitude with d-wave symmetry can be induced by short-range spin correlations even in the absence of pairing interactions. In the present scenario for the pseudogap, the normal state pseudogap is caused by the induced local spin-singlet amplitude due to short-range spin correlations, which compete in the low ene

T. Winiecki, C. S. Adams

We propose a finite-difference algorithm for solving the time-dependent Ginzburg-Landau (TDGL) equation coupled to the appropriate Maxwell equation. The time derivatives are discretized using a second order semi-implicit scheme which, for intermediate values of the Ginzburg-Landau parameter $κ$, allows time-steps two orders of magnitude larger than commonly

J. L. Hansen, M. van Hecke, C. Ellegaard, K. H. Andersen

Patterns of vortex ripples form when a sand bed is subjected to an oscillatory fluid flow. Here we describe experiments on the response of regular vortex ripple patterns to sudden changes of the driving amplitude a or frequency f. A sufficient decrease of f leads to a &#34;freezing&#34; of the pattern, while a sufficient increase of f leads to a supercritica

S. E. Korshunov

The ground state of the antiferromagnetic XY model with a kagome lattice is characterized by a well developed accidental degeneracy. As a consequence the phase transition in this system consists in unbinding of pairs of fractional vortices. Addition of the next-to-nearest neighbors (NNN) interaction leads to stabilization of the long-range order in chirality

A. E. Muryshev, P. O. Fedichev

We propose the novel mechanism leading to superfluidity breakdown in dilute Bose-condensed gases. We discuss the properties and highlight the role played by surface excitations in trapped condensates. We show that the critical velocity measured in recent experiments is nothing else but the critical velocity associated with the spontaneous creation of surface

C. Ciuhu, A. Lodder

We apply the theory of Takahashi and Tachiki in order to explain theoretically the dependence of the upper critical magnetic field of a S/N multilayer on the temperature. This problem has been already investigated in the literature, but with a use of an unphysical scaling parameter for the coherence length. We show explicitely that, in order to describe the

E. Rauwel-Buzin, W. Prellier, Ch. Simon, S. Mercone

Thin films of Nd$_{0.5}$Ca$_{0.5}$MnO$_{3}$ manganites with colossal magnetoresistance (CMR) properties have been synthesized by the Pulsed Laser Deposition technique on (100)-SrTiO$_{3}$. The lattice parameters of these manganites and correlatively their CMR properties can be controlled by the substrate temperature $T_{S}$. The maximum CMR effect at 75K, ca

Clément Sire, Paul L. Krapivsky

Solutions to the random Fibonacci recurrence x_{n+1}=x_{n} + or - Bx_{n-1} decrease (increase) exponentially, x_{n} = exp(lambda n), for sufficiently small (large) B. In the limits B --> 0 and B --> infinity, we expand the Lyapunov exponent lambda(B) in powers of B and B^{-1}, respectively. For the classical case of $β=1$ we obtain exact non-perturbative res

Cristina Bena, Leon Balents

We study the effect of electron-electron backscattering interactions on spin transport in a quantum wire. Even if these interactions have no significant effect on charge transport, they strongly influence the transport of spin. We use the quantum Boltzmann equation in the collision approximation to derive equations of motion for spin current and magnetizatio

A. Chattopadhyay, S. Das Sarma, A. J. Millis

We formulate a theory of doped magnetic semiconductors such as Ga$_{1-x}$Mn$_x$As which have attracted recent attention for their possible use in spintronic applications. We solve the theory in the dynamical mean field approximation to find the magnetic transition temperature $T_c$ as a function of magnetic coupling strength $J$ and carrier density $n$. We f

A. V. Fedorov, T. Valla, F. Liu, P. D. Johnson

High resolution spin-resolved photoemission is used to probe the properties of a Gd(0001) surface state. The state shows both a spin-mixing behavior reflecting the exchange of magnons with the local moments and a reduction of the exchange splitting with increasing temperature. The surface state polarization at low T suggests that the surface layer has an enh

Yoram Lithwick, Peter Goldreich

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation exists. We calculate the density spectrum in turbulent magnetized plasmas by extending the theory of incompressible MHD turbu

Stefanie Komossa, Michael Dahlem

In the last few years, giant-amplitude, non-recurrent X-ray flares have been observed from several non-active galaxies (NGC 5905, RXJ1242-11, RXJ1624+75, RXJ1420+53, RXJ1331-32). All of them share similar properties, namely: extreme X-ray softness in outburst, huge peak luminosity (up to ~10^{44} erg/s), and the absence of optical signs of Seyfert activity.

Pedro F. González-Diáz

This paper implements the idea of considering the instantonic creation of brane worlds whose five-dimensional bulk contains a negative cosmological constant and a scalar quintessence field with time-dependent equation of state, restricting to the case that the quintessence field couples minimally to Hilbert-Einstein gravity. We construct an Euclidean formali

J. E. Pringle, Ronald J. Allen, S. H. Lubow

In a recent paper, Elmegreen (2000) has made a cogent case, from an observational point of view, that the lifetimes of molecular clouds are comparable to their dynamical timescales. If so, this has important implications for the mechanisms by which molecular clouds form. In particular we consider the hypothesis that molecular clouds may form not by {\it in s

Jordi Jose, Alain Coc, Margarita Hernanz

Thermonuclear runaways driven by accretion into degenerate white dwarf cores are the source that power classical nova outbursts. In this paper, we identify the dominant nuclear paths involved in the synthesis of intermediate-mass elements, from Si to Ca, during such violent events. New evolutionary sequences of 1.35 Mo ONe novae have been computed, using upd

F. Bocchino, A. M. Bykov

\xmm ~observations of the X-ray feature 1SAX J0617.1+2221 in the IC443 supernova remnant are reported.We resolve the structure of the nebula into a compact core with a hard spectrum of photon index $γ= 1.63^{+0.11}_{-0.10}$ in the 2--10 keV energy range. The nebula also has an extended ($\sim 8\arcmin \times 5\arcmin$) X-ray halo, much larger than the radio

M. Fellhauer

Young star clusters in interacting galaxies are often found in groups or clusters of star clusters containing up to 100 single clusters. In our project we study the future fate of these clusters of star clusters. We find that the star clusters merge on time scales of a few dynamical crossing times of the super-cluster. The resulting merger object has similar

Una Hwang, Robert Petre, Stephen S. Holt, Andrew E. Szymkowiak

We use data from the Advanced CCD Imaging Spectrometer (ACIS) on the Chandra X-ray Observatory to image the shell surrounding the pulsar B0540-69, and to measure its spectral properties. Weak emission line features, notably of Fe, Mg and Si, indicate that the shell is composed primarily of ambient material heated by the blast wave. The shell emission in the

G. Fabbiano

Normal galaxies are faint and complex X-ray sources that provide very powerful probes for fundamental astrophysical questions. Examples include: the study of populations of X-ray emitting sources; the study of the entire spectrum of black-hole phenomena; and galaxy formation and evolution in interaction with the surrounding environment. While exciting, all t

M. Balcells, L. Dominguez-Palmero, A. Graham, R. F. Peletier

By combining surface brightness profiles from images taken in the HST/NICMOS F160W and ground-based (GB) $K$ bands, we have obtained NIR profiles for a well studied sample of inclined disk galaxies, spanning radial ranges from 20 pc to a few kpc. We fit PSF-convolved Sersic-plus-exponential laws to the profiles, and compare the results with the fits to the g

Edward L. Wright

Models of the zodiacal light are necessary to convert measured data taken from low Earth orbit into the radiation field outside the solar system. The uncertainty in these models dominates the overall uncertainty in determining the extragalactic background light for wavelengths < 100 microns.

M. Balcells

We study the innermost regions of bulges with surface brightness data derived from combined HST/NICMOS and ground-based NIR profiles. Bulge profiles to 1-2 kpc may be fit with Sersic laws, and show a trend with bulge-to-disk ratio: low-B/D bulges are roughly exponential, whereas higher-B/D bulges show increasing Sersic shape index $n$, indicating higher peak

X. -Z. Zheng

It has been firmly established that there exists a tight correlation between the central black hole mass and velocity dispersion (or luminosity) of elliptical galaxies, ``pseudobulges&#39;&#39; and bulges of galaxies, although the nature of this correlation still remains unclear. In this letter, we explore the possibility of extrapolating such a correlation

G. Kovacs

Frequency analysis of more than 300 stars of the OGLE database on Sculptor galaxy has led to the discovery of 18 double-mode RR Lyrae (RRd) variables. This yields a 20% incidence rate for double-mode pulsation among the variables previously classified as first overtone RR Lyrae stars in this galaxy. Most of the RRd stars cover the period range of 0.47d < P_0

C. L. Carilli, F. Bertoldi, A. Omont, P. Cox

We present Very Large Array (VLA) observations at 1.4 GHz and 5 GHz of a sample of 12 Quasi-stellar Objects (QSOs) at z = 3.99 to 4.46. The sources were selected as the brightest sources at 250 GHz from the recent survey of Omont et al. (2001). We detect seven sources at 1.4 GHz with flux densities, S_{1.4} > 50 microJy. These centimeter (cm) wavelength obse

Sarmistha Banik, Debades Bandyopadhyay

The formation of $K^-$ and $\bar K^0$ condensation in $β$-equilibrated hyperonic matter is investigated within a relativistic mean field model. In this model, baryon-baryon and (anti)kaon-baryon interactions are mediated by the exchange of mesons. It is found that antikaon condensation is not only sensitive to the equation of state but also to antikaon optic

Jinsong Deng, Yulei Qiu, Jinyao Hu

We analyze a time series of optical spectra of SN 1993J-like supernova 1996cb, from 14 days before maximum to 86 days after that, with a parameterized supernova synthetic-spectrum code SYNOW. Detailed line identification are made through fitting the synthetic spectra to observed ones. The derived photospheric velocity, decreasing from 11,000 km/s to 3,000 km

Yasuhiro Shioya, Kenji Bekki, Warrick J. Couch

By using a one-zone chemical and spectrophotometric evolution model of a disk galaxy undergoing a dusty starburst, we investigate, numerically, the optical spectroscopic properties in order to explore galaxy evolution in distant clusters. We adopt an assumption that the degree of dust extinction (represented by $A_V$) depends on the ages of starburst populat

Kenji Bekki, Warrick J. Couch, Drinkwater

Recent spectroscopic and morphological observational studies of galaxies around NGC 1399 in the Fornax Cluster (Drinkwater et al. 2000b) have discovered several `ultra-compact dwarf&#39; galaxies with intrinsic sizes of $\sim$ 100 pc and absolute $B$ band magnitudes ranging from -13 to -11 mag. In order to elucidate the origin of these enigmatic objects, we

Kenji Bekki, Warrick J. Couch, Yasuhiro Shioya

Recent spectroscopic observations of galaxies in distant clusters have revealed that the rate of star formation in star-forming galaxies is significantly suppressed with respect to their counterparts in the field at a similar redshift. It is, however, highly uncertain which physical processes are responsible for this suppression. We present the results of a

Howard E. Bond, D. J. Mullan, M. Sean O&#39;Brien, Edward M. Sion

V471 Tauri, an eclipsing system consisting of a hot DA white dwarf (WD) and a dK2 companion in a 12.5-hour orbit, is the prototype of the pre-cataclysmic binaries. The late-type component is magnetically active, due to its being constrained to rotate synchronously with the short orbital period. During a program of UV spectroscopy of V471 Tau, carried out wit

Xiao-Gang He

It has been argued in the literature that if a universe is expanding with an accelerating rate indefinitely, it presents a challenge to string theories due to the existence of event horizons. We study the fate of a currently accelerating universe. We show that the universe will continue to accelerate indefinitely if the parameter $ω= p/ρ$ of the equation of

M. A. Vasiliev

The dynamics of totally symmetric free massless higher spin fields in $AdS_d$ is reformulated in terms of the compensator formalism for AdS gravity. The $AdS_5$ higher spin algebra is identified with the star product algebra with the $su(2,2)$ vector (i.e., $o(4,2)$ spinor) generating elements. Cubic interactions of the totally symmetric bosonic higher spin

Martin Arkowitz, Jeffrey Strom

If F is a collection of topological spaces, then a homotopy class αin [X,Y] is called F-trivial if α_* = 0: [A,X] --> [A,Y] for all A in F. In this paper we study the collection Z_F(X,Y) of all F-trivial homotopy classes in [X,Y] when F = S, the collection of spheres, F = M, the collection of Moore spaces, and F = Σ, the collection of suspensions. Clearly Z_

Anderson Ilha, Clovis Wotzasek

In this report we study the dual equivalence between the generalized self-dual (SD) and topologically massive (TM) models. To this end we linearize the model using an auxiliary field and apply a gauge embedding procedure to construct a gauge equivalent model. We clearly show that, under the above conditions, a nonlinear SD model always has a duality equivale

M. Boettcher, C. D. Dermer

Blazar subclasses ranging from flat-spectrum radio quasars (FSRQs) through low-frequency-peaked BL Lac objects (LBLs) to high-frequency-peaked BL Lac objects (HBLs) exhibit a sequence of increasing spectral hardness with decreasing luminosity that cannot be explained solely by orientation effects. Using an analytic model for the synchrotron, synchrotron-self

John McDonald

We show that a gauge singlet scalar S, with a coupling to the Higgs doublet of the form lambda_{S} S^{\dagger}S H^{\dagger}H and with the S mass entirely generated by the Higgs expectation value, has a thermally generated relic density Omega_{S} \approx 0.3 if m_{S} \approx (2.9-10.5)(Omega_{S}/0.3)^{1/5}(h/0.7)^{2/5} MeV for Higgs boson masses in the range

Stéphane Lavignac, Isabella Masina, Carlos A. Savoy

We discuss the possibility of discriminating between different supersymmetric see-saw models by improving the experimental sensitivity to charged lepton flavour violating processes. Assuming a hierarchical neutrino mass spectrum, we classify realistic see-saw models according to how the hierarchy Delta m^2_{sun} << Delta m^2_{atm} is generated, and study the

Dmitri E. Kharzeev, Yuri V. Kovchegov, Eugene Levin

We show that instanton calculations in QCD become theoretically well defined in the gluon saturation environment which suppresses large size instantons. The effective cutoff scale is determined by the inverse of the saturation scale. We concentrate on two most important cases: the small-x tail of a gluon distribution of a high energy hadron or a large nucleu

V. Werner, P. von Brentano, R. F. Casten, J. Jolie

The concept of critical points in nuclear phase transitional regions is discussed from the standpoints of Q-invariants, simple observables and wave function entropy. It is shown that these critical points very closely coincide with the turning points of the discussed quantities, establishing the singular character of these points in nuclear phase transition

L. V. E. Koopmans, R. D. Blandford

We examine the claim by Oppenheimer et al. (2001) that the local halo density of white dwarfs is an order of magnitude higher than previously thought. As it stands, the observational data support the presence of a kinematically distinct population of halo white dwarfs at the >99% confidence level. A maximum-likelihood analysis gives a radial velocity dispers

R. Enberg, G. Ingelman, N. Timneanu

An improved understanding of nonperturbative QCD can be obtained by the recently developed soft color interaction models. Their essence is the variation of color string-field topologies, giving a unified description of final states in high energy interactions, e.g., diffractive and nondiffractive events in ep and ppbar. Here we present a detailed study of su

Je-An Gu, W-Y. P. Hwang

The presently accelerating universe may keep accelerating forever, eventually run into the event horizon problem, and thus be in conflict with the superstring idea. In the other way around, the current accelerating phase as well as the fate of the universe may be swayed by a negative cosmological constant, which dictates a big crunch. Based on the current ob

Ernesto F. Galvao

I show that a simple multi-party communication task can be performed more efficiently with quantum communication than with classical communication, even with low detection efficiency $η$. The task is a communication complexity problem in which distant parties need to compute a function of the distributed inputs, while minimizing the amount of communication b

Boris Dintrans, Rachid Ouyed

Properties of inertial modes of Jupiter are investigated for an n=1 polytropic description of the planet interior. We use the anelastic approximation to overcome the usual handicap of a severe spherical harmonics truncation. A powerful iterative solver then allows us to compute the frequencies of the most promising low-order modes using as many spherical har

Alex Kovner, Urs Achim Wiedemann

We give a simple quantum mechanical formulation of the eikonal propagation approximation, which has been heavily used in recent years in problems involving hadronic interactions at high energy. This provides a unified framework for several approaches existing in the literature. We illustrate this scheme by calculating the total, elastic, inelastic and diffra

C. U. Jung, J. Y. Kim, Min-Seok Park, Hun-Jeong Kim

We report on the effect of substitution for Cu on Tc of electron-doped infinite-layer superconductors Sr0.9La0.1Cu1-xRxO2, R = Zn and Ni. We found that Tc was nearly constant until x = 0.03 for R = Zn, while superconductivity was nearly suppressed for x = 0.02 with dTc/dx = 20 K/% for R = Ni. This behavior is very similar to that of conventional superconduct

Andrzej Czarnecki, Ernest Jankowski

Due to large QED anomalous dimensions of the electric and magnetic dipole operators, the rate of the rare muon decay mu --> e+gamma is suppressed by the factor [ 1- 8 alpha/pi ln(Lambda/m_mu) ], independent of the physics responsible for the lepton-flavor violation, except for the scale Lambda at which it occurs. For Lambda = 100 -- 1000 GeV, the resulting d

E. Gaztanaga

We compare the large scale galaxy clustering in the new SDSS early data release (EDR) with the clustering in the APM Galaxy Survey. We cut out pixel maps (identical in size and shape) from the SDSS and APM data to allow a direct comparison of the clustering. Here we concentrate our analysis on an equatorial SDSS strip in the South Galactic Cap (EDR/SGC) with

Aalok Misra

We analyse several open and mixed sector tree-level amplitudes in N=2 p-p&#39; systems with a constant magnetic B turned on. The 3-point function vanishes on-shell. The 4-point function, in the Seiberg-Witten (SW) low energy limit\cite{SW}, is local, {\it indicating the possible topological nature of the theory (in the SW low energy limit)} and the {\it poss

Samuel Wehrli, Didier Poilblanc, T. M. Rice

We study the charge profile of a C60-FET (field effect transistor) as used in the experiments of Schoen, Kloc and Batlogg. Using a tight-binding model, we calculate the charge profile treating the Coulomb interaction in a mean-field approximation. The charge profile behaves similarly to the case of a continuous space-charge layer, in particular it is confine

Wojciech Broniowski, Wojciech Florkowski

The assumption of simultaneous chemical and thermal freeze-outs of the hadron gas leads to a surprisingly accurate, albeit entirely conventional, explanation of the recently-measured RHIC pT spectra. The original thermal spectra are supplied with secondaries from decays of all resonances, and subsequently folded with a suitably parameterized expansion involv

Osamu Yasuda

It is shown generally that any oscillation probability in matter with approximately constant density coincides with that in vacuum to the first two nontrivial orders in $Δm^2_{jk}L/E$ if $|Δm^2_{jk}L/E|\ll 1$ and $|G_F N_e L|\ll 1$ are satisfied.

T. Christodoulakis, T. Gakis, G. O. Papadopoulos

In this work, the quantization of the most general Bianchi Type I geometry, with and without a cosmological constant, is considered. In the spirit of identifying and subsequently removing as many gauge degrees of freedom as possible, a reduction of the initial 6--dimensional configuration space is presented. This reduction is achieved by imposing as addition

B. Ananthanarayan, P. Büttiker, B. Moussallam

A recently proposed set of sum rules, based on the pion-Kaon scattering amplitudes and their crossing-symmetric conjugates are analysed in detail. A key role is played by the $l=0$ $ππ\to K\overline K$ amplitude which requires an extrapolation to be performed. It is shown how this is tightly constrained from analyticity, chiral counting and the available exp

V. V. Neustroev

We present results of non-simultaneous time-resolved photometric and spectroscopic observations of the little-studied dwarf nova FS Aur in quiescence. The spectrum of FS Aur shows strong and broad emission lines of hydrogen and HeI, and of weaker HeII 4686 and CIII/NIII blend, similar to other quiescent dwarf novae. All emission lines are single-peaked, howe

Eduard Vives, Antoni Planes

Within the Tsallis thermodynamics&#39; framework, and using scaling properties of the entropy, we derive a generalization of the Gibbs-Duhem equation. The analysis suggests a transformation of variables that allows standard thermodynamics to be recovered. Moreover, we also generalize Einstein&#39;s formula for the probability of a fluctuation to occur by mea

Jaime Merino, Ross H. McKenzie

In elemental metals the pairing of electrons leading to superconductivity is mediated by the vibrations of the crystal lattice and the pairs have spherical symmetry. For layered organic molecular crystals there is no consensus about the pairing symmetry or the mechanism of the superconductivity. We show theoretically that the mechanism of superconductivity f