June 2002 arXiv papers — page 2

Aram Harrow, Hoi-Kwong Lo

Entanglement concentration requires no classical communication, but the best prior art result for diluting to N copies of a partially entangled state requires an amount of communication on the order of sqrt(N) bits. Our main result is to prove this prior art result optimal up to a constant factor; any procedure for creating N partially entangled states from

D. Blume, B. D. Esry, C. H. Greene, N. N. Klausen

We present an extensive study of the static and dynamic properties of systems of spin-polarized tritium atoms. In particular, we calculate the two-body |F,m_F>=|0,0> s-wave scattering length and show that it can be manipulated via a Feshbach resonance at a field strength of about 870G. Such a resonance might be exploited to make and control a Bose-Einstein c

Randall D. Peters

When identifying instruments that have had great influence on the history of physics, none comes to mind more quickly than the pendulum. Though 'birthed' by Galileo in the 16th century, and in some respects nearly 'dead' by the middle of the 20th century; the pendulum experienced 'rebirth' by becoming an archetype of chaos. With the r

D. Iftimie, M. C. Lopes Filho, H. J. Nussenzveig Lopes

In this article we study the long-time behavior of incompressible ideal flow in a half plane from the point of view of vortex scattering. Our main result is that certain asymptotic states for half-plane vortex dynamics decompose naturally into a nonlinear superposition of soliton-like states. Our approach is to combine techniques developed in the study of vo

Cihan Saclioglu

Many of the most familiar features of our everyday environment, and some of our basic notions about it, stem from Relativistic Quantum Field Theory (RQFT). We argue in particular that the origin of common names, verbs, adjectives such as full and empty, the concepts of identity, similarity, Plato's Universals, natural numbers, and existence versus non-ex

N. Baboi, R. M. Jones, G. B. Bowden, V. Dolgashev

The coaxial wire method provides an experimental way of measuring wake fields without the need for a particle beam. A special setup has been designed and is in the process of being fabricated at SLAC to measure the loss factors and synchronous frequencies of dipole modes in both traveling and standing wave structures for the Next Linear Collider (NLC). The m

R. M. Jones, R. H. Miller, J. W. Wang, P. B. Wilson

In order to mitigate the effects of electrical breakdown (which have been found to occur in SLAC X-band traveling wave structures) standing wave structures are being considered for the NLC linac. At SLAC, structures consisting of 15 cells operating in the p accelerating mode are being tested for their electrical breakdown characteristics. In this paper the t

R. M. Jones, Z. Li, R. H. Miller, T. O. Raubenheimer

Earlier RDDS (Rounded Damped Detuned Structures) [1,2], designed, fabricated and tested at SLAC, in collaboration with KEK, have been shown to damp wakefields successfully. However, electrical breakdown has been found to occur in these structures and this makes them inoperable at the desired gradient. Recent results [3] indicate that lowering the group veloc

R. M. Jones, N. Baboi, N. M. Kroll

Dipole wakefields in NLC (Next Linear Collider) structures have been measured with ASSET [1] and well predicted by a circuit model [2]. However, the experimental technique is both time-consuming and expensive. Here, we report on kick factor and synchronous frequency determination for 1st and higher order dipole bands for TW (Traveling Wave) accelerators via

D. E. Kharzeev, J. Raufeisen

The goal of these lectures, oriented towards the students just entering the field, is to provide an elementary introduction to QCD and the physics of nuclear interactions at high energies. We first introduce the general structure of QCD and discuss its main properties. Then we proceed to Glauber multiple scattering theory which lays the foundation for the th

M. Barbaro, R. Cenni, A. Molinari, M. R. Quaglia

We search for approximate, but analytic solutions of the pairing problem for one pair of nucleons in many levels of a potential well. For the collective energy a general formula, independent of the details of the single particle spectrum, is given in both the strong and weak coupling regimes. Next the displacements of the solutions trapped in between the sin

N. Dinh Dang, N. Sandulescu, A. Arima

To be replaced with a revised version.

W. Brodowski, J. Paetzold, R. Bilger, H. Calen

Narrow structures in the range of a few MeV have been searched for in p p pi+ and p p pi- invariant mass spectra obtained from exclusive measurements of the p p -> p p pi+ pi- reaction at Tp = 725, 750 and 775 MeV using the PROMICE/WASA detector at CELSIUS. The selected reaction is particularily well suited for the search for NN and / or N Delta decoupled di

B. Sanchez-Rey, J. F. R. Archilla, F. Palmero, F. R. Romero

Recent papers that have studied variants of the Peyrard-Bishop model for DNA, have taken into account the long range interaction due to the dipole moments of the hydrogen bonds between base pairs. In these models the helicity of the double strand is not considered. In this particular paper we have performed an analysis of the influence of the helicity on the

George J. McNinch

Let G be a quasisimple algebraic group over an algebraically closed field of characteristic p>0. We suppose that p is very good for G; since p is good, there is a bijection between the nilpotent orbits in the Lie algebra and the unipotent classes in G. If the nilpotent X in Lie(G) and the unipotent u in G correspond under this bijection, and if u has order p

Massimo Giulietti, Gábor Korchmáros, Fernando Torres

Inspired by a recent paper of Garcia, Stichtenoth and Xing [2000, Compositio Math. 120, 137--170], we investigate the quotient curves of the Deligne-Lusztig curve associated to the Suzuki group.

Juan-Pablo Ortega

We generalize various symplectic reduction techniques to the context of the optimal momentum map. Our approach allows the construction of symplectic point and orbit reduced spaces purely within the Poisson category under hypotheses that do not necessarily imply the existence of a momentum map. We construct an orbit reduction procedure for canonical actions o

Hartmut Fuehr

We investigate the relevance of admissibility criteria based on Plancherel measure for the characterization of tight Weyl-Heisenberg frames with integer oversampling. For this purpose we observe that functions giving rise to such Weyl-Heisenberg frames are admissible with respect to the action of suitably defined type-I discrete group G. This allows to relat

Vyjayanthi Chari, Jacob Greenstein

We classify the simple infinite dimensional integrable modules with finite dimensional weight spaces over the quantized enveloping algebra of an untwisted affine algebra. We prove that these are either highest (lowest) weight integrable modules or simple submodules of a loop module of a finite-dimensional simple integrable module and describe the latter clas

P. Bozhilov

We consider probe p-branes dynamics in string theory backgrounds of general type. We use an action, which interpolates between Nambu-Goto and Polyakov type actions. This allows us to give a unified description for the tensile and tensionless branes. Firstly, we perform our analysis in the frequently used static gauge. Then, we obtain exact brane solutions in

Guang-Jiong Ni

In searching for the essence of special relativity, we have been gradually accumulating ten arguments focusing on one fundamental postulate based on quantum mechanics.A particle is always not pure. It always contain two contradictory fields, $ϕ(\vec{x},t)$ and $χ(\vec{x},t)$,which are coupled together with the symmetry $ϕ(-\vec{x},-t)\longrightarrowχ(\vec{x}

Gil Paz

In the framework of SU(3) symmetry, we present a general analysis of $B$ meson decays into two lighter uncharmed mesons (both pairs of pseudoscalar mesons and pairs of vector and pseudoscalar mesons). From the analysis we find constraints on $γ$ and discuss their validity. The most useful new constraint is obtained by considering the decay modes $B^{0} \to K

F. Boudjema, G. Bélanger, R. M. Godbole

We discuss effects of the light sparticles on decays of the lightest Higgs in a supersymmetric model with nonuniversal gaugino masses at the high scale, focusing on the `invisible' decays into neutralinos. These can impact significanlty the discovery possibilities of the lightest Higgs at the LHC. We show that due to these decays, there exist regions of

A. Bacchetta, R. Kundu, A. Metz, P. J. Mulders

We estimate the Collins function at a low energy scale by calculating the fragmentation of a quark into a pion at the one-loop level in the chiral invariant model of Manohar and Georgi. We give a useful parametrization of our results and we briefly discuss different spin and/or azimuthal asymmetries containing the Collins function and measurable in semi-incl

P. Aliani, V. Antonelli, R. Ferrari, M. Picariello

We present a short review of the existing evidence in favor of neutrino mass and neutrino oscillations which come from different kinds of experiments. We focus our attention in particular on solar neutrinos, presenting a global updated phenomenological analysis of all the available data and we comment on different possible future scenarios.

V. M. Braun, S. Gottwald, D. Yu. Ivanov, A. Schäfer

We argue that coherent production of hard dijets by linearly polarized real photons can provide direct evidence for chirality violation in hard processes, the first measurement of the magnetic susceptibility of the quark condensate and the photon distribution amplitude. It can also serve as a sensitive probe of the generalized gluon parton distribution. Nume

Tomislav Ivezic

In the invariant approach to special relativity (SR), which we call the ''true transformations (TT) relativity,'' a physical quantity in the four-dimensional spacetime is mathematically represented either by a true tensor or equivalently by a coordinate-based geometric quantity comprising both components and a basis. This invariant approach d

H. -W. Hammer, S. J. Puglia, M. J. Ramsey-Musolf, Shi-Lin Zhu

We analyze the q^2-dependence of the strange magnetic form factor, \GMS(q^2), using heavy baryon chiral perturbation theory (HBChPT) and dispersion relations. We find that in HBChPT a significant cancellation occurs between the O(p^2) and O(p^3) loop contributions. Consequently, the slope of \GMS at the origin displays an enhanced sensitivity to an unknown O

John Ellis, Martti Raidal, T. Yanagida

In the context of the seesaw mechanism, it is natural that the large solar and atmospheric neutrino mixing angles originate separately from large 2 by 2 mixings in the neutrino and charged-lepton sectors, respectively, and large mixing in the neutrino couplings is in turn more plausible if two of the heavy singlet neutrinos are nearly degenerate. We study th

I. P. Ivanov, N. N. Nikolaev

We describe the current status of the diffractive vector meson production calculations within the k_t-factorization approach. Since the amplitude of the vector meson production off a proton is expressed via the differential gluon structure function (DGSF), we take a closer look at the latter and present results of our new improved determination of the DGSF f

Guang-Jiong Ni

Experimental evidence and theoretical argument in favor the claim of neutrino being likely a superluminal particle, a tachyon, are discussed from six aspects with details.

C. Weiss

Exclusive proton-antiproton annihilation into two photons can be viewed as the Compton process in the crossed channel. At large s (~10 GeV^2) and |t|,|u| s this process can be described by a generalized partonic picture, analogous to the 'soft mechanism' in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a singl

K. S. Babu, Ernest Ma, J. W. F. Valle

The discrete non-Abelian symmetry $A_4$, valid at some high-energy scale, naturally leads to degenerate neutrino masses, without spoiling the hierarchy of charged-lepton masses. Realistic neutrino mass splittings and mixing angles (one of which is necessarily maximal and the other large) are then induced radiatively in the context of softly broken supersymme

Xuan Son Nguyen, Xuan-Yem Pham

We calculate the process- and polarization-dependent nonfactorizable terms $+AFw-widetilde{a}_{+AFw-lambda}$ of the B$+AFw-to$ J$/+AFw-Psi {+AFw-rm K^*}$ decay within the QCD-improved factorization approach. The longitudinal part $+AFw-widetilde{a}_{0}$ is infrared convergent and large enough to agree with recent experimental data, provided that the B-K$^*$

Ignacio Bediaga

We present recent results on scalar light mesons based on Dalitz plot analyses of charm decays from Fermilab experiment E791. Low mass scalar mesons are found to have large contributions to the decays studied, D^+\to K^-π^+π^+ and D^+, D_s^+\toπ^-π^+π^+. These results demonstrate the importance of charm decays as a new environment for the study of light meso

G. Abbiendi, R. G. Kellogg, D. Strom

A pair of compact Silicon-Tungsten calorimeters was operated in the OPAL experiment at LEP to measure the integrated luminosity from detection of Bhabha electrons scattered at angles between 25 and 58 mrad from the beam line. In the eight years from 1993 to 2000 the detector worked first at the Z mass peak and then at center of mass energies up to 209 GeV. T

H1 Collaboration, C. Adloff

A search for contributions to the reaction ep-> e pi^0 N^* from photon-Odderon fusion in the photoproduction regime at HERA is reported, at an average photon-proton centre-of-mass energy <W> = 215 GeV. The measurement proceeds via detection of the pi^0 decay photons, a leading neutron from the N^* decay, and the scattered electron. No pi^0 signal is observed

Douglas Bryman

A brief review of current results on rare kaon decays, particularly the charged and neutral K-> pi nu nubar channels, is presented along with prospects for future measurements.

Zoltán Perjés

A pair of wave equations is presented for the gravitational and electromagnetic perturbations of a charged black hole. One of the equations is uncoupled and determines the propagation of the electromagnetic perturbation. The other is for the propagation of the shear of a principal null direction and has a source term given by the solution of the first equati

Pankaj S. Joshi

End state of gravitational collapse and the related cosmic censorship conjecture continue to be amongst the most important open problems in gravitation physics today. My purpose here is to bring out several aspects related to gravitational collapse and censorship, which may help towards a better understanding of the issues involved. Possible physical constra

Imogen P. C. Heard, David Wands

We present a phase-plane analysis of cosmologies containing a scalar field $ϕ$ with an exponential potential $V \propto \exp(-λκϕ)$ where $κ^2 = 8πG$ and $V$ may be positive or negative. We show that power-law kinetic-potential scaling solutions only exist for sufficiently flat ($λ^2<6$) positive potentials or steep ($λ^2>6$) negative potentials. The latter

J. M. Pomeroy, J. Jacobsen, C. C. Hill, B. H. Cooper

Detailed KMC-MD (kinetic Monte Carlo-molecular dynamics) simulations of hyperthermal energy (10-100 eV) copper homoepitaxy have revealed a re-entrant layer-by-layer growth mode at low temperatures (50K) and reasonable fluxes (1 ML/s). This growth mode is the result of atoms with hyperthermal kinetic energies becoming inserted into islands when the impact sit

F. Plastina, G. Falci

We propose a scheme to implement a quantum information transfer protocol with a superconducting circuit and Josephson charge qubits. The information exchange is mediated by an L-C resonator used as a data bus. The main decoherence sources are analyzed in detail.

Thorsten Emig

A novel approach for calculating Casimir forces between periodically deformed objects is developed. This approach allows, for the first time, a rigorous non-perturbative treatment of the Casimir effect for disconnected objects beyond Casimir&#39;s original two-plate configuration. The approach takes into account the collective nature of fluctuation induced f

Wenbing Hu, Daan Frenkel, Vincent B. F. Mathot

In this paper, we report dynamic Monte Carlo simulations of melting and crystallization in a single-chain system. Their free energy barriers are calculated by the umbrella sampling method and can be described well by a simple expression DeltaF = n Deltaf+sigma (N-n)^(2/3), where n is the amount of molten bonds, Deltaf is the free energy change of each molten

V. G. Rostiashvili, N. -K. Lee, T. A. Vilgis

We investigate by the use of the Martin - Siggia - Rose generating functional technique and the self - consistent Hartree approximation, the dynamics of the ring homopolymer collapse (swelling) following an instantaneous change into a poor (good) solvent conditions.The equation of motion for the time dependent monomer - to - monomer correlation function is s

B. Jackson, E. Zaremba

We study transverse radial oscillations of an elongated Bose-Einstein condensate using finite temperature simulations, in the context of a recent experiment at ENS. We demonstrate the existence of a mode corresponding to an in-phase collective oscillation of both the condensate and thermal cloud. Excitation of this mode accounts for the very small damping ra

C. F. Roos, P. Cren, D. Guéry-Odelin, J. Dalibard

We study theoretically a scheme in which particles from an incident beam are trapped in a potential well when colliding with particles already present in the well. The balance between the arrival of new particles and the evaporation of particles from the trapped cloud leads to a steady-state that we characterize in terms of particle number and temperature. F

M. Veithen, X. Gonze, Ph. Ghosez

Using a plane wave pseudopotential approach to density functional theory we investigate the electron localization length in various oxides. For this purpose, we first set up a theory of the band-by-band decomposition of this quantity, more complex than the decomposition of the spontaneous polarization (a related concept), because of the interband coupling. W

Zhi-Rong Liu, Huajian Gao

A differential cluster variation method (DCVM) is proposed for analysis of spinoidal decomposition in alloys. In this method, lattice symmetry operations in the presence of an infinitesimal composition gradient are utilized to deduce the connection equations for the correlation functions and to reduce the number of independent variables in the cluster variat

Thomas Guhr, Bernd Kaelber

Financial correlation matrices measure the unsystematic correlations between stocks. Such information is important for risk management. The correlation matrices are known to be ``noise dressed&#39;&#39;. We develop a new and alternative method to estimate this noise. To this end, we simulate certain time series and random matrices which can model financial c

Yuri Martinez-Raton, Jose A. Cuesta

The phase diagram of a polydisperse mixture of uniaxial rod-like and plate-like hard parallelepipeds is determined for aspect ratios $κ=5$ and 15. All particles have equal volume and polydispersity is introduced in a highly symmetric way. The corresponding binary mixture is known to have a biaxial phase for $κ=15$, but to be unstable against demixing into tw

V. R. Shaginyan

A theory of strongly correlated electron or hole liquids with the fermion condensate is presented and applied to the consideration of quasiparticle excitations in high temperature superconductors, in their superconducting and normal states. This theory describes maximum values of the superconducting gap which can be as big as $Δ_1\sim 0.1ε_F$, with $ε_F$ bei

I. Sheikin, Y. Wang, F. Bouquet, P. Lejay

We report specific heat measurements on the heavy fermion compound CePd2Si2 in magnetic fields up to 16 T and in the temperature range 1.4-16 K. A sharp peak in the specific heat signals the antiferromagnetic transition at T_N ~ 9.3 K in zero field. The transition is found to shift to lower temperatures when a magnetic field is applied along the crystallogra

Dirk Kadau, Guido Bartels, Lothar Brendel, Dietrich E. Wolf

Cohesive powders tend to form porous aggregates which can be compacted by applying an external pressure. This process is modelled using the Contact Dynamics method supplemented with a cohesion law and rolling friction. Starting with ballistic deposits of varying density, we investigate how the porosity of the compacted sample depends on the cohesion strength

Parongama Sen, Kinjal Banerjee, Turbasu Biswas

We consider a one-dimensional network in which the nodes at Euclidean distance $l$ can have long range connections with a probabilty $P(l) \sim l^{-δ}$ in addition to nearest neighbour connections. This system has been shown to exhibit small world behaviour for $δ< 2$ above which its behaviour is like a regular lattice. From the study of the clustering coeff

D. Bolle, J. Busquets Blanco, G. M. Shim

The parallel dynamics of the fully connected Blume-Emery-Griffiths neural network model is studied at zero temperature for arbitrary using a probabilistic approach. A recursive scheme is found determining the complete time evolution of the order parameters, taking into account all feedback correlations. It is based upon the evolution of the distribution of t

D. R. Smith, D. Schurig, Marshall Rosenbluth, S. Schultz

Recently it has been proposed that a planar slab of material, for which both the permittivity and permeability have the values of -1, could bring not only the propagating fields associated with a source to a focus, but could also refocus the nonpropagating near-fields, thereby achieving a subdiffraction image. In this work we discuss the sensitivity of the s

J. B. Pendry, S. Anantha Ramakrishna

It has been shown that a slab of materials with refractive index = -1 behaves like a perfect lens focussing all light to an exact electromagnetic copy of an object. The original lens is limited to producing images the same size as the object, but here we generalise the concept so that images can be magnified. For two dimensional systems, over distances much

S. Anantha Ramakrishna, J. B. Pendry

A recent paper showed how to construct a lens that focuses near field radiation and hence produce resolution unlimited by wavelength. The prescription requires lossless materials with negative refractive index: finite loss cuts off the finer details of the image. In this paper we suggest compensating for losses by introducing optical gain media into the lens

S. Anantha Ramakrishna, J. B. Pendry, D. Schurig, D. R. Smith

We extend the ideas of the recently proposed perfect lens [J.B. Pendry, Phys. Rev. Lett. {\bf 85}, 3966 (2000)] to an alternative structure. We show that a slab of a medium with negative refractive index bounded by media of different positive refractive index also amplifies evanescent waves and can act as a near-perfect lens. We examine the role of the surfa

JB Pendry, D. R. Smith

In a recent Physical Review Letter [1] Valanju Walser and Valanju (VWV) called into question the basis of work on the so called negative index media (NIM). See for example [2,3]. The key point at issue is, `what is the group velocity of a wave in NIM?&#39;

Anton Bovier, Irina Kurkova

In this paper we review some recent rigorous results that provide an essentially complete solution of a class of spin glass models introduced by Derrida in the 1980ies. These models are based on Gaussian random processes on $\{-1,1\}^N$ whose covariance is a function of a ultrametric distance on that set. We prove the convergence of the free energy as well a

J. B. Pendry

In a recent Physical Review Letter [1] Garcia and Nieto Vesperinas (GNV) dispute the claim of perfect lensing made in [2]. The thrust of the GVN paper is that the solutions proposed in [2] imply infinite energy density and are therefore inadmissible. They claim that finite absorption leads to catastrophic collapse of the amplifying solutions vital to focussi

P. C. Frisch

High-resolution ultraviolet observations of nearby bright and faint stars are required to evaluate changes in the past and future galactic environments of the Sun, and the possibly impact of these changes on the interplanetary environment at 1 AU (around the Earth). The boundary conditions of the heliosphere and interplanetary environments are constrained by

M. S. Jackson, J. P. Halpern, E. V. Gotthelf, J. R. Mattox

We present the results of deep X-ray and gamma-ray observations of the Geminga pulsar obtained in the final years of the ASCA and CGRO missions, and an upper limit from RXTE. A phase-connected ephemeris from the gamma-rays is derived that spans the years 1973-2000, after allowing for a minor glitch in frequency of Delta f/f = 6.2 x 10^-10 in late 1996. ASCA

D. M. Peterson, Y. Liu, S. Portegies Zwart

We investigate the choice of stellar population for use as the Astrometric Grid for the Space Interferometry Mission (SIM). SIM depends on the astrometric stability of about 2000 stars, the so called Grid, against which the science measures are referenced. Low metallicity, and thus relatively high luminosity K giants are shown to be the population of choice,

J. H. Deady, P. J. Boyce, S. Phillipps, M. J. Drinkwater

The Fornax Cluster Spectroscopic Survey (FCSS) project utilises the 2dF multi-object spectrograph on the AAT. Its aim is to obtain spectra for a complete sample of all 14000 objects with 16.5<bj<19.7 irrespective of their morphology in a 12 sq deg area centred on the Fornax Cluster. A sample of 24 Fornax Cluster members has been identified from the first 2dF

Torsten A. Ensslin

Radio plasma injected by active radio galaxies into clusters of galaxies quickly becomes invisible due to radiative losses of the relativistic electrons. In this talk, the fate of radio plasma and its role for the galaxy cluster is discussed: buoyancy removes it from the central regions and allows to transfer its energy into the ambient gas. The remaining lo

Asantha Cooray, Ravi Sheth

We review the formalism and applications of the halo-based description of nonlinear gravitational clustering. In this approach, all mass is associated with virialized dark matter halos; models of the number and spatial distribution of the halos, and the distribution of dark matter within each halo, are used to provide estimates of how the statistical propert

Matthias Bartelmann, Francesca Perrotta, Carlo Baccigalupi

We study the effects of a dark energy component with equation of state p=w rho with constant w >= -1 on the formation of Cold Dark Matter (CDM) haloes. We find two main effects: first, haloes form earlier as w increases, and second, the amplitude of the dark-matter power spectrum gets reduced in order to remain compatible with the large scale Cosmic Microwav

V. Beckmann

The INTEGRAL Science Data Centre (ISDC) processes, archives and distributes data from the INTEGRAL mission. At the ISDC incoming data from the satellite are processed and searched for transient sources and Gamma-Ray bursts. The data are archived and distributed to the guest observers. As soon as the data are public, any astronomer can access the data via the

Pasquale Blasi

The most energetic particles ever detected exceed $10^{20}$ eV in energy. Their existence represents at the same time a great challenge for particle physics and astrophysics, and a great promise of providing us for a probe of the validity of the laws of Nature in extreme conditions. We review here the most recent data and the future perspectives for detectio

P. de Vicente, J. Martin-Pintado, R. Neri, A. Rodriguez-Franco

We present images of the J=10-9 rotational lines of HC3N in the vibrationally excited levels 1v7, 1v6 and 1v5 of the hot core (HC) in Orion KL. The images show that the spatial distribution and the size emission from the 1v7 and 1v5 levels are different. While the J=10-9 1v7 line has a size of 4&#39;&#39;x 6&#39;&#39; and peaks 1.1&#39;&#39; NE of the 3 mm c

M. C. Smith, S. Mao, P. Wozniak, A. Udalski

We describe a highly unusual microlensing event, OGLE-1999-BUL-19, which exhibits multiple peaks in its light curve. The Einstein radius crossing time for this event is approximately one year, which is unusually long. We show that the motion of the Earth induces these multiple peaks in the light curve, since the relative transverse velocity of the lens proje

Frode K. Hansen, Domenico Marinucci, Paolo Natoli, Nicola Vittorio

We present a new, model-independent approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern. Our approach is based on the empirical distribution function of the normalized spherical harmonic expansion coefficients a_lm of a nearly full-sky CMB map, like the ones expected from forthcoming satellite experiments. Using

M. Haywood

The mean metallicity of the Milky Way thin disc in the solar neighbourhood is still a matter of debate, and has recently been subject to upward revision (Haywood, 2001). Our star sample was drawn from a set of solar neighbourhood dwarfs with photometric metallicities. In a recent study, Reid (2002) suggests that our metallicity calibration, based on Geneva p

M. Loewe, C. Villavicencio

The density corrections, in terms of the isospin chemical potential $μ_I$, to the mass of the pions are investigated in the framework of the SU(2) low energy effective chiral invariant lagrangian. As a function of temperature and $μ_I =0$, the mass remains quite stable, starting to grow for very high values of $T$, confirming previous results. However, the d

Bartlomiej Dybiec, Ewa Gudowska-Nowak, Pawel F. Gora

The problem of escape of a Brownian particle in a cusp-shaped metastable potential is of special importance in nonadiabatic and weakly-adiabatic rate theory for electron transfer (ET) reactions. Especially, for the weakly-adiabatic reactions, the reaction follows an adiabaticity criterion in the presence of a sharp barrier. In contrast to the non-adiabatic c

I. I. Mazin, A. G. Petukhov, L. Chioncel, A. I. Lichtenstein

While LDA+U method is well established for strongly correlated materials with well localized orbitals, its application to weakly correlated metals is questionable. By extending the LDA Stoner approach onto LDA+U, we show that LDA+U enhances the Stoner factor, while reducing the density of states. Arguably the most important correlation effects in metals, flu

D. Blaschke, V. Pervushin, D. Proskurin, S. Vinitsky

We introduce the hypothesis that the matter content of the universe can be a product of the decay of primordial vector bosons. The effect of the intensive cosmological creation of these primordial vector $W, ~Z $ bosons from the vacuum is studied in the framework of General Relativity and the Standard Model where the relative standard of measurement identify

Duncan Galloway, Deepto Chakrabarty, Edward Morgan, Ronald Remillard

We have identified the third known accretion-powered millisecond pulsar, XTE J0929-314, with the Rossi X-Ray Timing Explorer. The source is a faint, high-Galactic-latitude X-ray transient (d >~ 5 kpc) that was in outburst during 2002 April-June. The 185 Hz (5.4 ms) pulsation had a fractional rms amplitude of 3-7% and was generally broad and sinusoidal, altho

Neil R. Constable, Neil D. Lambert

We present new non-Abelian solitonic configurations in the low energy effective theory describing a collection of N parallel D1--branes. These configurations preserve 1/4, 1/8, 1/16 and 1/32 of the spacetime supersymmetry. They are solutions to a set of generalised Nahm&#39;s equations which are related to self-duality equations in eight dimensions. Our solu

M. A. Abramowicz, T. Bulik, M. Bursa, W. Kluzniak

We find evidence that the two high frequency QPOs in Sco X-1 are, more often than not, approximately in the 2:3 frequency ratio familiar from studies of black hole candidates (e.g., XTE J1550-564, Remillard et al. 2002). This implies that the double kHz QPO phenomenon in neutron stars has its origin in properties of strong-field gravity and has little to do

T. Laustsen, F. Verstraete, S. J. van Enk

We consider a variant of the entanglement of assistance, as independently introduced by D.P. DiVincenzo {\em et al.} ({\tt quant-ph/9803033}) and O. Cohen (Phys. Rev. Lett. {\bf 80}, 2493 (1998)). Instead of considering three-party states in which one of the parties, the assistant, performs a measurement such that the remaining two parties are left with on a

Jose F. Morales, Henning Samtleben

We study the holographic duals of type II and heterotic matrix string theories described by warped AdS_3 supergravities. By explicitly solving the linearized equations of motion around near horizon D-string geometries, we determine the spectrum of Kaluza-Klein primaries for type I, II supergravities on warped AdS_3 x S^7. The results match those coming from

Leonard Parker, William Komp, Daniel A. T. Vanzella

As shown by Parker and Raval, quantum field theory in curved spacetime gives a possible mechanism for explaining the observed recent acceleration of the universe. This mechanism, which differs in its dynamics from quintessence models, causes the universe to make a transition to an accelerating expansion in which the scalar curvature, R, of spacetime remains

Thomas Nevins

Fix a scheme $X$ over a field of characteristic zero that is equipped with an action of a reductive algebraic group $G$. We give necessary and sufficient conditions for a $G$-equivariant coherent sheaf on $X$ or a bounded-above complex of $G$-equivariant coherent sheaves on $X$ to descend to a good quotient $X//G$. This gives a description of the coherent de

Min-xin Huang

We consider non-planar contributions to the correlation functions of BMN operators in free N = 4 super Yang Mills theory. We recalculate these non-planar contributions from a different kind of diagram and find some exact agreements. The vertices of these diagrams are represented by free planar three point functions, thus our calculations provide some interes

C. G. Torre

The polarized Gowdy ${\bf T}^3$ vacuum spacetimes are characterized, modulo gauge, by a ``point particle&#39;&#39; degree of freedom and a function $ϕ$ that satisfies a linear field equation and a non-linear constraint. The quantum Gowdy model has been defined by using a representation for $ϕ$ on a Fock space $\cal F$. Using this quantum model, it has recent

M. Diehl, P. Kroll, C. Vogt

We study the handbag contribution to two-photon annihilation into baryon-antibaryon pairs at large energy and momentum transfer. We derive factorization of the process amplitude into a hard gamma gamma -> q qbar subprocess and form factors describing the soft q qbar -> B Bbar transition, assuming that the process is dominated by configurations where the (ant

Pedro A. Pury, Manuel O. Caceres

We present a unified framework for first-passage time and residence time of random walks in finite one-dimensional disordered biased systems. The derivation is based on exact expansion of the backward master equation in cumulants. The dependence on initial condition, system size, and bias strength is explicitly studied for models with weak and strong disorde

R. G. Scott, A. M. Martin, T. M. Fromhold, S. Bujkiewicz

We study the dynamics of Bose-Einstein condensates in an optical lattice and harmonic trap. The condensates are set in motion by displacing the trap and initially follow simple semiclassical paths, shaped by the lowest energy band. Above a critical displacement, the condensate undergoes Bragg reflection. For high atom densities, the first Bragg reflection ge

A. Díaz-Sánchez, A. Pérez-Garrido, A. Urbina, J. D. Catalá

We study the relaxation for growing interfaces in quenched disordered media. We use a directed percolation depinning model introduced by Tang and Leschhorn for 1+1-dimensions. We define the two-time autocorrelation function of the interface height C(t&#39;,t) and its Fourier transform. These functions depend on the difference of times t-t&#39; for long enoug

Dipak Munshi, Yun Wang

Future weak lensing surveys will directly probe the clustering of dark matter, in addition to providing a test for various cosmological models. Recent studies have provided us with the tools which can be used to construct the complete probability distribution function for convergence fields. It is also possible to construct the bias associated with the hot-s

M. Tsuchiizu, A. Furusaki

The ground-state phase diagram of the half-filled two-leg Hubbard ladder with inter-site Coulomb repulsions and exchange coupling is studied by using the strong-coupling perturbation theory and the weak-coupling bosonization method. Considered here as possible ground states of the ladder model are four types of density-wave states with different angular mome

Michal Majewski

Mass formulae for light meson multiplets derived by means of exotic commutator technique are written for complex masses and considered as complex mass sum rules (CMSR). The real parts of the (CMSR) give the well known mass formulae for real masses (Gell-Mann--Okubo, Schwinger and Ideal Mixing ones) and the imaginary parts of CMSR give appropriate sum rules f

Hiroyuki Abe, Tomohiro Inagaki

The dynamically generated fermion mass is investigated in the flat brane world with (4+delta)-dimensional bulk space-time, and in the Randall-Sundrum (RS) brane world. We consider the bulk Yang-Mills theory interacting with the fermion confined on a four-dimensional brane. Based on the effective theory below the reduced cutoff scale on the brane, we formulat

C. Quesne

We construct a new family of q-deformed coherent states $|z>_q$, where $0 < q < 1$. These states are normalizable on the whole complex plane and continuous in their label $z$. They allow the resolution of unity in the form of an ordinary integral with a positive weight function obtained through the analytic solution of the associated Stieltjes power-moment p

Masahito Hayashi

General formulas of entanglement concentration are derived by using an information-spectrum approach for the i.i.d. sequences and the general sequences of partially entangled pure states. That is, we derive general relations between the performance of the entanglement concentration and the eigenvalues of the partially traced state. The achievable rates with