July 2002 arXiv papers — page 5

L. Brink, P. Ramond, X. Xiong

Some massless supermultiplets appear as the trivial solution of Kostant's equation, a Dirac-like equation over special cosets. We study two examples; one over the coset SU(3)/SU(2) times U(1) contains the N=2 hypermultiplet in (3+1) dimensions with U(1) as helicity; the other over the coset F_4/SO(9) describes the N=1 supermultiplet in eleven dimensions,

Ian Shipsey

We report on the physics potential of a proposed conversion of the CESR machine and the CLEO detector to a charm and QCD factory: ``CLEO-c and CESR-c'' that will make crucial contributions to quark flavor physics this decade, and may offer our best hope for mastering non-perturbative QCD, which is essential if we are to understand strongly coupled se

Belle Collaboration, B. C. K. Casey

We report the results of a study of two-body B meson decays to the complete set of K pi, pi pi, and K K final states. The study is performed on a data sample of 31.7 +/- 0.3 million B B-bar events recorded on the Upsilon(4S) resonance by the Belle experiment at KEKB. We observe significant signals in all K pi final states and in the pi+ pi- and pi+ pi0 final

Gavriel Segre

The gedanken-experiment of Einstein's lift is analyzed in order of determining whether the free-falling observer inside the lift can detect the eventual topological non-triviality of space-time

M. I. Wanas, M. Melek, M. E. Kahil

The Bazanski approach, for deriving the geodesic equations in Riemannian geometry, is generalized in the absolute parallelism geometry. As a consequence of this generalization three path equations are obtained. A striking feature in the derived equations is the appearance of a torsion term with a numerical coefficients that jumps by a step of one half from e

E. Schachinger, J. P. Carbotte

In recent years a unified phenomenological picture for the hole doped high-T_c cuprates has emerged for a spin and charge spectroscopy. Spectral anomalies have been interpreted as evidence of charge carrier coupling to a collective spin excitation present in the optical conductivity, in ARPES (angular resolved photoemission), and in tunneling data. These ano

Stefan Mashkevich, Stephane Ouvry

The thermodynamics of the anyon model projected on the lowest Landau level (LLL) of an external magnetic field is addressed in the anti-screening regime, where the flux tubes carried by the anyons are parallel to the magnetic field. It is claimed that the LLL-anyon equation of state, which is known in the screening regime, can be analytically continued in th

G. Blumberg, P. Littlewood, A. Gozar, B. S. Dennis

We used transport and Raman scattering measurements to identify the insulating state of self-doped spin 1/2 two-leg ladders of Sr_{14}Cu_{24}O_{41} as a weakly pinned, sliding density wave with non-linear conductivity and a giant dielectric response that persists to remarkably high temperatures.

Norikazu Todoroki, Yohtaro Ueno, Seiji Miyashita

We study the three-dimensional generalized six-state clock model at values of the energy parameters, at which the system is considered to have the same behavior as the stacked triangular antiferromagnetic Ising model and the three-state antiferromagnetic Potts model. First, we investigate ordered phases by using the Monte Carlo twist method (MCTM). We confir

Shigeki Miyasaka, Yoichi Okimoto, Yoshinori Tokura

Anisotropic optical spectra coupled with antiferromagnetic spin ordering (SO) and orbital ordering (OO) have been investigated for single crystals of LaVO_{3} and YVO_{3}. The orbital-dependent Mott-Hubbard gap transitions are observed around 2 eV. The transitions composed of the two peaks show distinct anisotropy and selection rules, reflecting the respecti

Suk-Jin Yoon, Young-Wook Lee

One of the long-standing problems in modern astronomy is the curious division of Galactic globular clusters, the &#34;Oosterhoff dichotomy,&#34; according to the properties of their RR Lyrae stars. Here, we find that most of the lowest-metallicity ([Fe/H]<-2.0) clusters, which are essential to an understanding of this phenomenon, display a planar alignment i

A. Noriega-Crespo, A. Cotera, E. Young, H. Chen

We present near infrared images in H2 at 2.12um of the HH 7/11 outflow and its driving source SVS 13 taken with HST NICMOS 2 camera, as well as archival Ha and [SII] optical images obtained with the WFPC2 camera. The NICMOS high angular resolution observations confirm the nature of a small scale jet arising from SVS 13, and resolve a structure in the HH 7 wo

Elena Pian

Optical, infrared and ultraviolet observations of GRB fields have allowed detection of counterparts and host galaxies of the high energy transients, thus crucially contributing to our present knowledge of the GRB phenomenon. Measurements of afterglow variable emission, polarized light, redshifted absorption and emission line spectra, as well as host galaxies

D. E. Segall, T. A. Arias

Through the use of perturbation theory, in this work we develop a method which allows for a substantial reduction in the size of the plane-wave basis used in density-functional calculations. This method may be used for both pseudopotentials and all-electron calculations and is particularly beneficial in the latter case. In all cases, the approach has the adv

T. Sumi, F. Abe, I. A. Bond, R. J. Dodd

We analyze the data of the gravitational microlensing survey carried out by by the MOA group during 2000 towards the Galactic Bulge (GB). Our observations are designed to detect efficiently high magnification events with faint source stars and short timescale events, by increasing the the sampling rate up to 6 times per night and using Difference Image Analy

Yu-Qi Chen

The renormalization issue of the reparameterization invariance in heavy quark effective theory and NRQCD is investigated. I argue that the renormalization of the transformation of the heavy quark field under the variation of the velocity parameter V is attributed to the renormalization of the small component field in the proposed transformation. I show that

F. T. Vasko

The short-range defect with reduced symmetry is studied in the framework of KP-approach taking into account a matrix structure of potential energy in the equations for envelope functions. The case of the narrow-gap semiconductor, with defects which are non-symmetric along the [001], [110], or [111] directions, is considered. Resonant state at a single defect

Alfonso García-Parrado, José M M Senovilla

We define and study a new kind of relation between two diffeomorphic Lorentzian manifolds called {\em causal relation}, which is any diffeomorphism characterized by mapping every causal vector of the first manifold onto a causal vector of the second. We perform a thorough study of the mathematical properties of causal relations and prove in particular that t

Kaori Otsuki, Grant J. Mathews, Toshitaka Kajino

We review recent observational and theoretical results concerning the presence of actinide nuclei on the surfaces of old halo stars and their use as an age determinant. We present model calculations which show that the observed universality of abundances for 56 < Z < 75 elements in these stars does not imply a unique astrophysical site for the r-process. Nei

F. Delgado, H. Cruz, J. G. Muga

The transient response of a stationary state of a quantum particle in a step potential to an instantaneous change in the step height (a simplified model for a sudden bias switch in an electronic semiconductor device) is solved exactly by means of a semianalytical expression. The characteristic times for the transient process up to the new stationary state ar

Guang Song, Andreas Klappenecker

The controlled-not gate and the single qubit gates are considered elementary gates in quantum computing. It is natural to ask how many such elementary gates are needed to implement more elaborate gates or circuits. Recall that a controlled-U gate can be realized with two controlled-not gates and four single qubit gates. We prove that this implementation is o

Rajeev K. Azad, J. Subba Rao, Wentian Li, Ramakrishna Ramaswamy

By using the Jensen-Shannon divergence, genomic DNA can be divided into compositionally distinct domains through a standard recursive segmentation procedure. Each domain, while significantly different from its neighbours, may however share compositional similarity with one or more distant (non--neighbouring) domains. We thus obtain a coarse--grained descript

V. A. Kuz&#39;menko

It is assumed, that the clumps of lines do not connected with states mixing and IVR, but they are the result of breaking (destruction) of the process of averaging of momentum of inertia of molecules during the vibration motion of atoms. Rough estimates of the widths of clumps of lines in absorption spectra of some acetylenic derivatives were made with this m

J. A. Sheikh, P. Ring, E. Lopes, R. Rossignoli

A systematic study of the pairing-correlations derived from various particle-number projection methods is performed in an exactly soluble cranked-deformed shell model Hamiltonian. It is shown that most of the approximate particle-number projection methods including the method of Lipkin-Nogami, which is used quite extensively in nuclear structure studies, bre

A. I. Titov, M. Fujiwara, T. S. -H. Lee

For coherent photoproduction of phi and omega mesons from deuteron at forward angles, the isovector pi-exchange amplitude is strongly suppressed. We show a possibility to study the non-diffractive channels associated with the unnatural parity exchange in phi-photoproduction and with the baryon resonance excitations in omega-photoproduction by measuring the s

R. Fedele, H. Schamel, V. I. Karpman, P. K. Shukla

On the basis of a recently-proposed method to find solitary solutions of generalized nonlinear Schrodinger equations [1]-[3], the existence of an envelope solitonlike solutions of a nonlinear Schrodinger equation containing an anti-cubic nonlinearity (|Psi|^{-4} Psi) plus a &#34;regular&#34; nonlinear part is investigated. In particular, in case the regular

Nguyen Tien Zung

We give a geometric proof of Conn&#39;s linearization theorem for analytic Poisson structures, without using the fast convergence method.

Meirav Amram, Mina Teicher

This paper is the first in a series of three papers concerning the surface T times T. In this paper we study the degeneration of T times T and the regeneration of its degenerated object. We study the braid monodromy and its regeneration.

L. Martina, Kur. Myrzakul, R. Myrzakulov

The study of the relation between the Weierstrass inducing formulae for constant mean curvature surfaces and the completely integrable euclidean nonlinear sigma-model suggests a connection among integrable sigma -models in a background and other type of surfaces. We show how a generalization of the Weierstrass representation can be achieved and we establish

Nikolai Dokuchaev, Ulrich Haussmann

We investigate an optimal investment problem with a general performance criterion which, in particular, includes discontinuous functions. Prices are modeled as diffusions and the market is incomplete. We find an explicit solution for the case of limited diversification of the portfolio, i.e. for the portfolio compression problem. By this we mean that an admi

Nikolai Dokuchaev

We study optimal investment problem for a diffusion market consisting of a finite number of risky assets (for example, bonds, stocks and options). Risky assets evolution is described by Ito&#39;s equation, and the number of risky assets can be larger than the number of driving Brownian motions. We assume that the risk-free rate, the appreciation rates and th

Richard Drociuk

Starting from the solution to Bring&#39;s equation the root ambiguity is removed from the solution to the quintic equation. This gives the five complex roots of the quintic equation as indicated by Gauss&#39;s Fundamental Theorem of Algebra.r

Joe Harris, Jason Starr

This is a continuation of &#34;Rational curves on hypersurfaces of low degree&#34;, math.AG/0203088. We prove that if d^2+d+1 < n and d > 2, then for a general hypersurface X_d in P^n of degree d, for each degree e the space of rational curves of degree e on X is itself a rationally connected variety.

Angela Gammella

We study the tangential Poisson cohomology (TP-cohomology) of regular Poisson manifolds, first defined by Lichnerowicz using contravariant tensor fields. We show that for a regular Poisson manifold M, the TP-cohomology coincides with the leafwise de Rham (or Cech) cohomology of the symplectic foliation of M. Its computation in various degrees leads to open,

Thomas Mohaupt

We give a pedagogical introduction to string theory, D-branes and p-brane solutions.

Dmitri Antonov

Langevin equation describing soft modes in the quark-gluon plasma is reformulated on the loop space. The Cauchy problem for the resulting loop equation is solved for the case when the nonvanishing components of the gauge potential correspond to the Cartan generators of the SU(N)-group and are proportional to a constant unit vector in the Cartan subalgebra. T

Sergio E. Joras, Rudnei O. Ramos

We study the consequences of noise and dissipation for parametric resonance during preheating. The effective equations of motion for the inflaton and the radiation field are obtained and shown to present self-consistent noise and dissipation terms. The equations exhibit the usual parametric resonance phenomenon, allowing for exponential amplification of the

The BABAR Collaboration, B. Aubert

A Dalitz plot analysis of the D0 hadronic decays D0 -> K0 K- pi+, D0 -> K0bar K+ pi- and D0 -> K0bar K+ K- is presented. This analysis is based on a data sample of 22 fb-1 collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC running on or near the Y(4S) resonance. The events are selected from continuum e+ e- annihilations using

Shahram Rahatlou

We present updated results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 62 million Y(4S) --> B Bbar decays collected between 1999 and 2001 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure sin2beta = 0.75 +/- 0.09 (stat) +/- 0.04 (syst

The BABAR Collaboration, B. Aubert

We present preliminary results of the analysis of B -> D0 h decays, with h = pi, K and the D0 reconstructed in the channels K- pi+, K- pi+ pi+ pi-, K- pi+ pi0 and in the CP eigenstate K-K+, using data collected by the BABAR detector during the years 2000-2002 at the PEP-II asymmetric-energy B Factory at SLAC. We have measured the ratio of the branching fract

C. B. Hart, R. Held, P. K. Hoiland, S. Jenks

The problems of hazardous radiation and collisions with matter on a warp driven ship pose considerable obstacles to this possibility for interstellar travel. A solution to these problems lies in the Broeck metric. It is demonstrated that both threats to the ship will be greatly reduced. It is also shown that the horizon problem no longer exists.

Jan Chomicki

The handling of user preferences is becoming an increasingly important issue in present-day information systems. Among others, preferences are used for information filtering and extraction to reduce the volume of data presented to the user. They are also used to keep track of user profiles and formulate policies to improve and automate decision making. We pr

L. Li, Y. Y. Proskuryakov, A. K. Savchenko, E. H. Linfield

On a high-mobility 2D electron gas we have observed, in strong magnetic fields (omega_{c} tau > 1), a parabolic negative magnetoresistance caused by electron-electron interactions in the regime of k_{B} T tau / hbar ~ 1, which is the transition from the diffusive to the ballistic regime. From the temperature dependence of this magnetoresistance the interacti

M. A. Hayward, E. J. Cussen, J. B. Claridge, M. Bieringer

We present the synthesis and structural characterisation of a transition metal oxide hydride, LaSrCoO_3H_{0.7}, which adopts an unprecedented structure in which oxide chains are bridged by hydride anions to form a two- dimensional extended network. The metal centers are strongly coupled by their bonding with both oxide and hydride ligands to produce magnetic

A. Irizawa, A. Higashiya, S. Kasai, T. Sasabayashi

High-resolution bulk-sensitive photoemission has been measured for pyrochlore oxide Cd2Re2O7. Temperature variations of the spectral shapes between 20 and 250 K are obviously observed for the Re 4f inner core and the valence band spectra. The Re 5d states are dominant for the DOS near the Fermi level.

Sumiyoshi Abe, Norikazu Suzuki

The statistical properties of time intervals between significant earthquakes are found to be described by the Zipf-Mandelbrot-Tsallis-type distribution.

D. E. Harris, A. Finoguenov, A. H. Bridle, M. J. Hardcastle

During the course of an investigation of the interaction of the radio galaxy M84 and its ambient cluster gas, we found excess X-ray emission aligned with the northern radio jet. The emission extends from the X-ray core of the host galaxy as a weak bridge and then brightens to a local peak coincident with the first detectable radio knot at approx. 2.5&#34; fr

Oleg Kargaltsev, George G. Pavlov, Divas Sanwal, Gordon P. Garmire

We observed the compact central object CXOU J085201.4--461753 in the supernova remnant G266.2--1.2 (RX J0852.0--4622) with the Chandra ACIS detector in timing mode. The spectrum of this object can be described by a blackbody model with the temperature kT=404 eV and radius of the emitting region R=0.28 km, at a distance of 1 kpc. Power-law and thermal plasma

W. Cui, Y. X. Feng, S. N. Zhang, M. W. Bautz

We present results from observations of persistent black hole candidates with the High Energy Transmission Gratings aboard the Chandra X-ray Observatory. The sources include LMC X-1, LMC X-3, GRS 1758-258, and Cyg X-1. Along with the published results on 1E1740.7-2942, we have completed a high-resolution spectroscopic survey of such systems. The observed X-r

Grzegorz Wardzinski, Andrzej A. Zdziarski, Marek Gierlinski, J. Eric Grove

We analyse five observations of the X-ray binary GX 339-4 by the soft gamma-ray OSSE detector on board CGRO simultaneous with either Ginga or RXTE observations. The source was bright during four of them, with the luminosity of L ~ 10^{37} erg/s and the spectrum typical for hard states of accreting black holes, and it was in an off state during the fifth one,

Matthew O&#39;Dowd, C. Megan Urry, Riccardo Scarpa

We have studied the host galaxies of a sample of radio-loud AGN spanning more than four decades in the energy output of the nucleus. The core sample includes 40 low-power sources (BL Lac objects) and 22 high-power sources (radio-loud quasars) spanning the redshift range z~0.15 to z~0.5, all imaged with the high spatial resolution of HST. All of the sources a

L. Benet, H. A. Weidenmueller

The embedded ensembles were introduced by Mon and French as physically more plausible stochastic models of many--body systems governed by one--and two--body interactions than provided by standard random--matrix theory. We review several approaches aimed at determining the spectral density, the spectral fluctuation properties, and the ergodic properties of th

Hitoshi Nishino, Subhash Rajpoot

We present massive N=2 supergravity with SO(2)-gauging in nine-dimensions by direct construction. A full lagrangian and transformation rules are fixed, respectively up to quartic and quadratic fermion terms. Corresponding to the generalized Scherk-Schwarz dimensional reduction utilizing SL(2,R) symmetry, this theory allows three arbitrary mass parameters m_0

Leticia Carigi

Two sets of observational carbon stellar yields for low-and-intermediate mass stars are computed based on planetary nebula abundances derived from C II lambda 4267 and C III lambda lambda 1906 + 1909 lines, respectively. These observational yields are assumed in chemical evolution models for the solar vicinity and the Galactic disk. C/O values observed in st

M. Pillsbury, H. Orland, A. Zee

We enumerate possible topologies of pseudoknots in single-stranded RNA molecules. We use a steepest-descent approximation in the large N matrix field theory, and a Feynman diagram formalism to describe the resulting pseudoknot structure.

Sergei Gukov, James Sparks, David Tong

We conjecture a topology changing transition in M-theory on a non-compact asymptotically conical Spin(7) manifold, where a 5-sphere collapses and a CP(2) bolt grows. We argue that the transition may be understood as the condensation of M5-branes wrapping the 5-sphere. Upon reduction to ten dimensions, it has a physical interpretation as a transition of D6-br

Charles J. Hailey, Kaya Mori

Recently Sanwal et al. (2002) reported the first clear detection of absorption features in an isolated neutron star, 1E1207.4-5209. Remarkably their spectral modeling demonstrates that the atmosphere cannot be Hydrogen. They speculated that the neutron star atmosphere is indicative of ionized Helium in an ultra-strong (~1.5x10^{14} G) magnetic field. We have

A. M. Bratkovsky, A. P. Levanyuk

We present the analytical study of stability loss and evolution of domain structure in inhomogeneous ferroelectric and ferroelastic samples for exactly solvable models. The model assumes a short-circuited ferroelectric capacitor (free ferroelastic) with two regions with slightly different critical temperatures Tc1 Tc2, where Tc1-Tc2 << Tc1, Tc2. We show that

A. A. Starobinsky, I. I. Tkachev

We consider observational constraints on creation of particles induced by hypothetical trans-Planckian effects during the current stage of the Universe expansion. We show that compatibility with the diffuse gamma-ray background measured by the EGRET experiment strongly restricts this creation. In particular, it rules out the possibility to detect signatures

I. L. Buchbinder, S. James Gates, W. D. Linch, J. Phillips

We construct an N=1 supersymmetric Lagrangian model for the massive superspin-1 superfield. The model is described by a dynamical spinor superfield and an auxiliary chiral scalar superfield. On-shell this model leads to a spin-1/2, spin-3/2 and two spin-1 propagating component fields. The superfield action is given and its structure in the fermionic componen

Joseph Rudnick, David Jasnow

A lattice of uniformly charged, infinitesimally thin, rods decorated with an ordered array of counterions exhibits anomalous behavior as the spacing between the rods is varied. In particular, the counterion lattice undergoes a sequence of structural shearing, or &#34;tilting,&#34; phase transformations as the spacing between the rods decreases. The potential

J. Barranco, O. G. Miranda, T. I. Rashba, V. B. Semikoz

We show that spin flavor precession solutions to the solar neutrino problem, although preferred by the latest solar data, are ruled out by the first results from the KamLAND reactor experiment, at more than 3_sigma. An illustrative chi2 plot comparing these descriptions with oscillations is given.

Abdesslam Arhrib

We study the production of a heavy CP-odd $A^0$ boson in association with a photon $e^+e^-\to A^0γ$ and a Z boson $e^+e^-\to A^0 Z$ as well as the single production of $A^0$ via $e^+e^- \to ν_e\barν_e A^0$ in the MSSM with CP violating phases. In the case of $e^+e^-\to A^0γ/ A^0 Z$, we show that the squark contribution, which vanishes in the MSSM with real p

L. R. Tagirov, B. P. Vodopyanov, B. M. Garipov

We present calculations of quantized conductance and magnetoresistance in nanosize point contacts between two ferromagnetic metals. When conductance is open for only one conduction electrons spin-projection, the magnitude of magnetoresistance is limited by the rate of conduction electron spin-reversal processes. For the case when both spin-channels contribut

Abhay Ashtekar, Stephen Fairhurst, Joshua L. Willis

A program was recently initiated to bridge the gap between the Planck scale physics described by loop quantum gravity and the familiar low energy world. We illustrate the conceptual problems and their solutions through a toy model: quantum mechanics of a point particle. Maxwell fields will be discussed in the second paper of this series which further develop

Lung-Yih Chiang, Peter Coles, Pavel Naselsky

In the standard paradigm for cosmological structure formation, clustering develops from initially random-phase (Gaussian) density fluctuations in the early Universe by a process of gravitational instability. The later, non-linear stages of this process involve Fourier mode-mode interactions that result in a complex pattern of non-random phases. We present a

R. Mainini, A. V. Maccio&#39;, S. A. Bonometto

We study the cluster mass function and its evolution in different models with Dark Energy arising from a self--interacting scalar field, with Ratra-Peebles and SUGRA potentials. Computations are based on a Press & Schechter approximation. The mass functions we obtain are compared with results holding for open models or models with Dark Energy due to a cosmol

Y. Lallouet, D. Davesne, C. Pujol

In this paper we apply hydrodynamics for systems with continuous broken symmetries to heavy ion collisions in the framework of (1+1) dimensional Bjorken model. The temperature profile with respect to proper time determined in that context exhibits no differences with the ideal fluid. On the contrary, it is shown that the profile obtained when Müller-Israel-S

Ezzat G. Bakhoum

The recently introduced reconciliation of the theories of special relativity and wave mechanics implies that the mass-energy equivalence principle must be expressed mathematically as H = mv^2, where H is the total energy of a particle, m is its relativistic mass, and v is its velocity; not H = mc^2 as was widely believed. In this paper, the equation H = mv^2

J. I. Illana, M. Masip

The observation of charged lepton flavor non-conservation would be a clear signature of physics beyond the Standard Model. In particular, supersymmetric (SUSY) models introduce mixings in the sneutrino and the charged slepton sectors which could imply flavor-changing processes at rates accessible to upcoming experiments. In this paper we analyze the possibil

Yan V Fyodorov, H. -J Sommers

The paper discusses progress in understanding statistical properties of complex eigenvalues (and corresponding eigenvectors) of weakly non-unitary and non-Hermitian random matrices. Ensembles of this type emerge in various physical contexts, most importantly in random matrix description of quantum chaotic scattering as well as in the context of QCD-inspired

Marco Bruni, Leonardo Gualtieri, Carlos F. Sopuerta

An implicit fundamental assumption in relativistic perturbation theory is that there exists a parametric family of spacetimes that can be Taylor expanded around a background. The choice of the latter is crucial to obtain a manageable theory, so that it is sometime convenient to construct a perturbative formalism based on two (or more) parameters. The study o

Peter Kohlert, Klaus Kassner, Chaouqi Misbah

Amplitude expansions are used to determine steady states of a semi-infinite solid subject to the Grinfeld instability in systems with a fixed (wave)length. We present two methods to obtain high-order weakly nonlinear results. Using the system size as a control parameter, we circumvent the problem that there is no instability threshold for an extended system

J. M. Roman, G. Sierra, J. Dukelsky

We have found the elementary excitations of the exactly solvable BCS model for a fixed number of particles. These turn out to have a peculiar dispersion relation, some of them with no counterpart in the Bogoliubov picture, and unusual counting properties related to an old conjecture made by Gaudin. We give an algorithm to count the number of excitations for

David D. Reid

This paper describes an approach that uses flat-spacetime dimension estimators to estimate the manifold dimension of causal sets that can be faithfully embedded into curved spacetimes. The approach is invariant under coarse graining and can be implemented independently of any specific curved spacetime. Results are given based on causal sets generated by rand

Guido Rizzi, Matteo Luca Ruggiero

We study the space geometry of a rotating disk both from a theoretical and operational approach, in particular we give a precise definition of the space of the disk, which is not clearly defined in the literature. To this end we define an extended 3-space, which we call relative space: it is recognized as the only space having an actual physical meaning from

Harald Schmid

In this paper we consider bound state solutions, i.e., normalizable time-periodic solutions of the Dirac equation in the exterior region of an extreme Kerr black hole with mass $M$ and angular momentum $J$. It is shown that for each azimuthal quantum number $k$ and for particular values of $J$ the Dirac equation has a bound state solution, and that the energ

Bernd Sing

We consider (generalized) Kolakoski sequences on an alphabet with two even numbers. They can be related to a primitive substitution rule of constant length ell. Using this connection, we prove that they have pure point dynamical and pure point diffractive spectrum, where we make use of the strong interplay between these two concepts. Since these sequences ca

P. Aniello, A. Porzio, S. Solimeno

A unitary transformation of the N-ion Jaynes-Cummings hamiltonian is proposed. It is shown that any approximate expression of the evolution operator associated with the transformed hamiltonian retains its validity independently from the intensity of the external driving field. In particular, using the rotating wave approximation, one obtains a solution for t

Tatsuto Murayama, Masato Okada

We apply statistical mechanics to an inverse problem of linear mapping to investigate the physics of the irreversible compression. We use the replica symmetry breaking (RSB) technique with a toy model to demonstrate the Shannon&#39;s result. The rate distortion function, which is widely known as the theoretical limit of the compression with a fidelity criter

M. Gilfanov, M. Revnivtsev, S. Molkov

Using Fourier frequency resolved X-ray spectroscopy we study short term spectral variability in luminous LMXBs. With RXTE/PCA observations of 4U1608--52 and GX340+0 on the horizontal/normal branch of the color-intensity diagram we show that aperiodic and quasiperiodic variability on ~ sec-msec time scales is caused primarily by variations of the luminosity o

P. Vagner, P. Markos, M. Mosko, Th. Schaepers

We study coherent electron transport in a one-dimensional wire with disorder modeled as a chain of randomly positioned scatterers. We derive analytical expressions for all statistical moments of the wire resistance $ρ$. By means of these expressions we show analytically that the distribution $P(f)$ of the variable $f=\ln(1+ρ)$ is not exactly Gaussian even in

M. Aunola

We present a general, asymptotical solution for the discretised harmonic oscillator. The corresponding Schrödinger equation is canonically conjugate to the Mathieu differential equation, the Schrödinger equation of the quantum pendulum. Thus, in addition to giving an explicit solution for the Hamiltonian of an isolated Josephon junction or a superconducting

Martin Lueders, Andrea Bordoni, Nicola Manini, Andrea Dal Corso

We compute, based on density-functional electronic-structure calculations, the Coulomb couplings in the h_u highest occupied orbital of molecular C60. We obtain a multiplet-averaged Hubbard U ~ 3 eV, and four Hund-rule-like intra-molecular multiplet-splitting terms, each of the order of few hundreds of meVs. According to these couplings, all C60^n+ ions shou

M. Alves, J. Barcelos-Neto, M. Novello, J. M. Salim

We study the obtainment of a time-dependent cosmological constant at D=2 in a model based on the Jackiw-Teitelboim cosmology. We show that the cosmological term goes to zero asymptotically and can induce a nonsingular behavior at the origin.

N. A. Smirnova, C. Volpe

The theoretical evaluation of major nuclear structure effects on the asymmetry of allowed Gamow-Teller beta-decay rates in light mirror nuclei is presented. The calculations are performed within the shell model, using empirical isospin-nonconserving interaction and realistic Woods-Saxon radial wave functions. The revised treatment of p-shell nuclei is supple

Jiro Kodaira, Cong-Feng Qiao

The double spin asymmetry for exclusive $J/ψ$ pair production in the polarized $p-p$ collisions at RHIC is investigated. Our study shows that the asymmetry in this process is measurable at RHIC-SPIN experiments in the near future, and, hence it can be used to determine the gluon distribution function $ΔG (x)$ in the polarized nucleon.

Tsuneo Suzuki, M. N. Chernodub

We discuss the effect of dynamical charged particles in U(1)^{N-1} Abelian effective theories of QCD. Screening and confinement at zero temperature are explained qualitatively. The effect of dynamically charged particle is expressed in terms of an effective action of integer electric currents. When a screening is expected, the static potential shows a flatte

K. Tsushima, F. C. Khanna

$Λ^+_c$- and $Λ_b$-hypernuclei are studied in the quark-meson coupling (QMC) model. Comparisons are made with the results for $Λ$-hypernuclei studied in the same model previously. Although the scalar and vector potentials felt by the $Λ$, $Λ_c^+$ and $Λ_b$ in the corresponding hypernuclei multiplet which has the same baryon numbers are quite similar, the wav

Elliott J. Mason, Marius A. Albota, Friedrich Koenig, Franco N. C. Wong

We demonstrate efficient generation of collinearly propagating, highly nondegenerate photon pairs in a periodically-poled lithium niobate cw parametric downconverter with an inferred pair generation rate of 1.4*10^7/s/mW of pump power. Detection of an 800-nm signal photon triggers a thermoelectrically-cooled 20%-efficient InGaAs avalanche photodiode for the

Jeroen Dehaene, Maarten Van den Nest, Bart De Moor, Frank Verstraete

We present new algorithms for mixed-state multi-copy entanglement distillation for pairs of qubits. Our algorithms perform significantly better than the best known algorithms. Better algorithms can be derived that are tuned for specific initial states. The new algorithms are based on a characterization of the group of all locally realizable permutations of t

G. Metalidis, P. Bruno

The Casimir effect results from alterations of the zero-point electromagnetic energy introduced by boundary-conditions. For ferromagnetic layers separated by vacuum (or a dielectric) such boundary-conditions are influenced by the magneto-optical Kerr effect. We will show that this gives rise to a long-range magnetic interaction and discuss the effect for two

E. Bagan, M. Baig, R. Munoz-Tapia

We obtain a simple formula for the average gate fidelity of a linear map acting on qudits. It is given in terms of minimal sets of pure state preparations alone, which may be interesting from the experimental point of view. These preparations can be seen as the outcomes of certain minimal positive operator valued measures. The connection of our results with

H. Barnum, E. Knill, G. Ortiz, L. Viola

Unentangled pure states on a bipartite system are exactly the coherent states with respect to the group of local transformations. What aspects of the study of entanglement are applicable to generalized coherent states? Conversely, what can be learned about entanglement from the well-studied theory of coherent states? With these questions in mind, we characte

Rachel E. Scherr, Peter S. Shaffer, Stamatis Vokos

This article reports on an investigation of student understanding of the concept of time in special relativity. A series of research tasks are discussed that illustrate, step-by-step, how student reasoning of fundamental concepts of relativity was probed. The results indicate that after standard instruction students at all academic levels have serious diffic

Javier Davila, Christos Vassilicos

DNS and laboratory experiments show that the spatial distribution of straining stagnation points in homogeneous isotropic 3D turbulence has a fractal structure with dimension D_s = 2. In Kinematic Simulations the time exponent gamma in Richardson&#39;s law and the fractal dimension D_s are related by gamma = 6/D_s. The Richardson constant is found to be an i

C. M. Casciola, P. Gualtieri, R. Benzi, R. Piva

Turbulent shear flows, such as those occurring in the wall region of turbulent boundary layers, manifest a substantial increase of intermittency with respect to isotropic conditions. This suggests a close link between anisotropy and intermittency. However, a rigorous statistical description of anisotropic flows is, in most cases, hampered by the inhomogeneit

P. K. Shukla, R. Fedele, M. Onorato, N. L. Tsintsadze

The nonlinear coupling between the light beams and non-resonant ion density perturbations in a plasma is considered, taking into account the relativistic particle mass increase and the light beam ponderomotive force. A pair of equations comprising a nonlinear Schrodinger equation for the light beams and a driven (by the light beam pressure) ion-acoustic wave

R. Fedele, P. K. Shukla, M. Onorato, D. Anderson

It is shown that partial incoherence, in the form of stochastic phase noise, of a Langmuir wave in an unmagnetized plasma gives rise to a Landau-type damping. Starting from the Zakharov equations, which describe the nonlinear interaction between Langmuir and ion-acoustic waves, a kinetic equation is derived for the plasmons by introducing the Wigner-Moyal tr

N. J. A. Sloane

A brief report on recent work on the sphere-packing problem.