March 2003 arXiv papers — page 3

C. Q. Geng, C. C. Liu

We study the rare decays of $B_{s} \to M_s\ell \bar{\ell}$ ($M_s=η, η',ϕ$ and $\ell=ν,e,μ,τ$) in the standard model. With the hadronic form factors evaluated in the light front and constituent quark models, we estimate the decay branching ratios, respectively. We also discuss the longitudinal lepton polarization and forward-backward asymmetries.

C. Aydin, A. H. Yilmaz

The coupling constants g$_{ρηγ}$ and g$_{ωηγ}$ are calculated using QCD sum rules method by studying the three point ${ρηγ}$ and ${ωηγ}$ correlation functions. A comparison of the results with the values of the coupling constants that are deduced from the experimentally measured decay widths of $ρ\to ηγ$ and $ω\to ηγ$ decays is performed.

Yuval Grossman, Gilad Perez

The standard model flavor structure can be explained in theories where the fermions are localized on different points in a compact extra dimension. We explain how models with two bulk scalars compactified on an orbifold can produce such separations in a natural way. We show that, generically, models of Gaussian overlaps are unnatural since they require very

J. H. Field

The definition of `lepton flavour eigenstates' introduced in a recent paper hep-ph/0302045 is in disagreement with the Standard Model prediction for the structure of the leptonic charged current and implies the absence of neutrino oscillations following pion decay, in contradiction to experimental data

Chongxing Yue, Yanming Zhang, Hong Li

Many models, such as topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, predict the existence of extra U(1) gauge bosons $Z^{\prime}$, which couple preferentially to the third generation. The lepton flavor violating (LFV) signals of these new particles at the future $e^{+}e^{-}$ colliders (LCs) are discussed via calculating its contr

Gabriela Barenboim, Joseph Lykken

It is commonly believed that unbroken supersymmetry (SUSY) implies that all members of a supermultiplet have the same mass. We demonstrate that this is not true, by exhibiting a simple counterexample. We employ the formalism of homeotic fermions, in a simple model where CPT conjugate fermions have different masses. This model can be supersymmetrized to a hyp

A. van Hameren

The adaptive multi-channel method is applied to derive probability distributions from data samples. Moreover, an explicit algorithm is introduced, for which both the channel weights and the channels themselves are adaptive, and which can be used both for data analysis and for importance sampling in Monte Carlo integration. Finally, it is pointed out how the

A. Ali Khan, T. Bakeyev, M. Göckeler, R. Horsley

An algorithm for separating the high- and low-frequency molecular dynamics modes in Hybrid Monte Carlo simulations of gauge theories with dynamical fermions is presented. The separation is based on splitting the pseudo-fermion action into two parts, as was initially proposed by Hasenbusch. We propose to introduce different evolution time-scales for each part

Hiroshi Suzuki

We show that, with an appropriate choice of a Dirac operator, there is a remnant of chiral anomalies in the reduced model in which there is no coordinate dependences of the gauge field. This result is obtained by exploring a topological nature of chiral anomalies associated to Ginsparg-Wilson-type lattice Dirac operators.

K. A. Ispirian, M. K. Ispiryan

It is shown that the interaction of an electron beam with polarized electromagnetic wave of laser photons propagating in the same direction in a short interaction region results in significant transversal deflection of the electrons which can be used for production of femtosecond electron and synchrotron radiation beams, for chopping the electron beams and c

Rodrigo Aros, Mauricio Contreras, Jorge Zanelli

The equivalence between the path integrals for first order gravity and the standard torsion-free, metric gravity in 3+1 dimensions is analyzed. Starting with the path integral for first order gravity, the correct measure for the path integral of the metric theory is obtained.

Howard G. Preston, Franklin Potter

We explore a theory of large-scale gravitational quantization, using the general relativistic Hamilton-Jacobi equation to create quantization conditions via a new scalar wave equation dependent upon the total mass and the total vector angular momentum only. Instead of h-bar, a local invariant quantity proportional to the total angular momentum dictates the q

Sergei M. Kopeikin

Gravitational physics of VLBI experiment conducted on September 8, 2002 and dedicated to measure the speed of gravity (a fundamental constant in the Einstein equations) is treated in the first post-Newtonian approximation. Explicit speed-of-gravity parameterization is introduced to the Einstein equations to single out the retardation effect caused by the fin

Massimo Di Pierro

We present Matrix Distributed Processing, a C++ library for fast development of efficient parallel algorithms. MDP is based on MPI and consists of a collection of C++ classes and functions such as lattice, site and field. Once an algorithm is written using these components the algorithm is automatically parallel and no explicit call to communication function

F. Evangelista, A. Ruocco, V. Corradini, M. P. Donzello

We present the growth morphology, the long range ordering, and the evolution of the valence band electronic states of ultra-thin films of copper phthalocyanine (CuPc) deposited on the Au(110)-(1x2) reconstructed surface, as a function of the organic molecule coverage. The Low Energy Electron Diffraction (LEED) patterns present a (5x3) reconstruction from the

T. Galla, A. C. C. Coolen, D. Sherrington

We present an exact dynamical solution of a spherical version of the batch minority game (MG) with random external information. The control parameters in this model are the ratio of the number of possible values for the public information over the number of agents, and the radius of the spherical constraint on the microscopic degrees of freedom. We find a ph

S. Urazhdin, H. Kurt, W. P. Pratt, J. Bass

We compare magnetization switching in Co/Cu/Co nanopillars with uncoupled and dipole-field coupled Co layers. In uncoupled nanopillars, current-driven switching is hysteretic at low magnetic field H and changes to reversible, characterized by telegraph noise, at high H. We show that dipolar coupling both affects the switching current and causes the switching

C. I. Ventura, B. Alascio

Recently, based on the refined crystal structure of Pr0.6Ca0.4MnO3 from neutron diffraction, Daoud-Aladine et al.[PRL89,97205(2002)] have proposed a new ground state structure for the half-doped manganites R0.5Ca0.5MnO3, where R is a trivalent ion like Bi,La,Pr,Sm or Y. Their proposal describes the CE magnetic structure attributed to these materials as an ar

J. Alexandre, N. E. Mavromatos, Sarben Sarkar

It has been argued in previous works by the authors that nodal excitations in (2+1)-dimensional doped antiferromagnets might exhibit, in the spin-charge separation framework and at specific regions of the parameter space, a supersymmetry between spinons and holons. This supersymmetry has been elevated to a N=2 extended supersymmetry of composite operators of

V. Hardy, S. Hebert, A. Maignan, C. Martin

This paper reports on peculiar metamagnetic transitions which take place in antiferromagnetic, charge and orbitally ordered (AFCOO) manganites. At very low temperatures, the virgin magnetization curves of some of these compounds exhibit several, sharp steps giving rise to a staircase-like shape. This staircase effect is shown to be sensitive to various exper

F. D. Morrison, Y. Luo, I. Szafraniak, V. Nagarajan

We report the independent invention of ferroelectric nanotubes from groups in several countries. Devices have been made with three different materials: lead zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium bismuth tantalate SrBi2Ta2O9 (SBT). Several different deposition techniques have been used successfully, including misted CSD

Ville Mustonen, R. Rajesh

The number of solid partitions of a positive integer is an unsolved problem in combinatorial number theory. In this paper, solid partitions are studied numerically by the method of exact enumeration for integers up to 50 and by Monte Carlo simulations using Wang-Landau sampling method for integers up to 8000. It is shown that, for large n, ln[p(n)]/n^(3/4) =

A. Lucarelli, S. Lupi, M. Ortolani, P. Calvani

In their Comment to a recent paper of ours [Lucarelli et al., PRL 92, 037002 (2003)], Tajima et al. (cond-mat 0303493) argue that the samples of La(2-x)Sr(x)CuO(4) where we find far-infrared peaks below 150 cm-1 (which suggest a charge stripe scenario) are not single crystals or are miscut. Here we show that the spectral feature on which this criticism is ba

Didier Poilblanc, D. J. Scalapino, Sylvain Capponi

Single-particle diagonal and off-diagonal Green's functions of a 2-leg t-J ladder at 1/8-doping are investigated by Exact Diagonalisations techniques. A numerically tractable expression for the superconducting gap is proposed and the frequency dependence of the real and imaginary parts of the gap are determined. The role of the low-energy gapped spin mod

M. A. Micheelsen, C. Rischel, J. Ferkinghoff-Borg, R. Guerois

We have analyzed dynamics on the complex free energy landscape of protein folding in the FOLD-X model, by calculating for each state of the system the mean first passage time to the folded state. The resulting kinetic map of the folding process shows that it proceeds in jumps between well-defined, local free energy minima. Closer analysis of the different lo

B. Kaulakys, T. Meskauskas

Simple analytically solvable models are proposed exhibiting 1/f spectrum in wide range of frequency. The signals of the models consist of pulses (point process) which interevent times fluctuate about some average value, obeying an autoregressive process with very small damping. The power spectrum of the process can be expressed by the Hooge formula. The prop

R. Tyer, W. M. Temmerman, Z. Szotek, G. Banach

The first-principles SIC-LSD theory is utilized to study electronic, magnetic and orbital phenomena in LaMnO$_{3}$. The correct ground state is found, which is antiferro orbitally ordered with the spin magnetic moments antiferromagnetically aligned. Jahn-Teller energies are found to be the largest energy scale. In addition it is the Jahn-Teller interaction w

S. A. Alavi, M. Sarbishaei

We show that the structure of the quantum group $su_{q}(2)$ is intimately related to the random walks on a two dimentional lattice. Using this connection we obtain an appropriate candidate for the exact area distribution of closed random walks of length $N$ on a two dimensional square lattice. We compare our results with exact enumeration.

Ned Wingreen, Hao Li, Chao Tang

Only about 1,000 qualitatively different protein folds are believed to exist in nature. Here, we review theoretical studies which suggest that some folds are intrinsically more designable than others, {\it i.e.} are lowest energy states of an unusually large number of sequences. The sequences associated with these folds are also found to be unusually thermal

Shih-Ping Lai, T. Velusamy, W. D. Langer, T. B. H. Kuiper

We have investigated the physical and chemical status of the pre-protostellar core B68. A previous extinction study suggested that the density profile of B68 is remarkably consistent with a Bonnor-Ebert sphere with 2.1 $M_{\odot}$ at 16 K. We mapped B68 in C3H2, CCS, and NH3 with the Deep Space Network (DSN) 70m telescope at Goldstone. Our results show that

Markus Cristinziani

Antimatter search results of the Alpha Magnetic Spectrometer (AMS) detector are presented. About 100 million triggers were collected in the 1998 precursor flight onboard space shuttle Discovery. This ten day mission exposed the detector on a 51.7 degrees orbit at an altitude around 350 km. Identification of charged cosmic rays is achieved by multiple energy

Leslie Looney, Lee Mundy, Jack Welch

We present modeling results for six of the eleven deeply embedded systems from our sub-arcsecond 2.7 mm wavelength continuum interferometric survey. The modeling, performed in the uv plane, assumes dust properties, allows for a power-law density profile, uses a self-consistent, luminosity conserving temperature profile, and has an embedded point source to re

Paulo Sergio Custodio, J. E. Horvath

Supermassive Black Holes are the most entropic objects found in the universe. The Holographic Bound (HB) to the entropy is used to constrain their formation time with initial masses $\sim{10}^{6-8}M_{\odot}$, as inferred from observations. We find that the entropy considerations are more limiting than causality for this "direct" formation. Later we a

Michiel Reuland, Wil van Breugel, Huub Roettgering, Wim de Vries

We report deep Keck narrow-band Lya images of the luminous z > 3 radio galaxies 4C 41.17, 4C 60.07, and B2 0902+34. The images show giant, 100-200 kpc scale emission line nebulae, centered on these galaxies, which exhibit a wealth of morphological structure, including extended low surface brightness emission in the outer regions, radially directed filaments,

Alister W. Graham

The best-fitting B, R, I and K-band (Sersic R^(1/n) bulge + exponential disk) model parameters for the de Jong & van der Kruit (1994) sample of 86 spiral galaxies are made electronically available. This sample covers all spiral galaxy types and provides the largest homogeneous set of structural parameters for spiral galaxies modeled with an R^(1/n) bulge.

Sydney A. Barnes

It is suggested that the three-segmented morphology of the soft X-ray emission from cluster and field stars may be understood in terms of the recent classification of rotating stars into three kinds: those lying on the convective sequence, on the interface sequence, or in the gap between them.

Sydney A. Barnes

We propose a simple interpretation of the rotation period data for solar- and late-type stars. The open cluster and Mt. Wilson star observations suggest that rotating stars lie primarily on two sequences, initially called I and C. Some stars lie in the intervening gap. These sequences, and the fractional numbers of stars on each sequence evolve systematicall

Peter A. Becker

We obtain an exact, closed-form expression for the time-dependent Green's function solution to the Kompaneets equation. The result, which is expressed as the integral of a product of two Whittaker functions, describes the evolution in energy space of a photon distribution that is initially monoenergetic. Effects of spatial transport within a homogeneous

E. Baron, Eric Lentz, Peter H. Hauschildt

Motivated by recent 3-D calculations of the explosion of Type Ia supernova via a pure deflagration we calculate the observed spectra at 15-25 days past maximum light of a parameterized model which has a considerable fraction of unburnt C+O in the central regions. Rather than attempting a self consistent 3-D calculation, which is beyond the scope of current c

Giorgio Matt, Matteo Guainazzi

We have performed a detailed analysis of the XMM-Newton observation of IGR J16318-4848, to study the properties of the matter responsible for the obscuration and for the emission of Fe and Ni lines. Even if the line of sight material has a column density of about 2x10^24 cm^-2, from the Fe Kalpha line EW and Compton Shoulder we argue that the matter should h

E. M. Burbidge, G. Burbidge, H. C. Arp, S. Zibetti

The starburst / AGN galaxy M82 was studied by Dahlem, Weaver and Heckman using X-ray data from ROSAT and ASCA, as part of their X-ray survey of edge-on starburst galaxies. They found seventeen unresolved hard-X-ray sources around M82, in addition to its strong nuclear source, and other X-rays within the main body of M82. We have measured optical point source

G. Efstathiou

I review two fundamental contributions that Fred Hoyle made to the theory of galaxy formation. Hoyle was the first to propose that protogalaxies acquired their angular momentum via tidal torques from neighbouring perturbations during a period of gravitational instability. To my knowledge, he was also the first to suggest that the masses of galaxies could be

Fabio Bresolin, Rolf-Peter Kudritzki

Photospheric radiation momentum is efficiently transferred by absorption through metal lines to the gaseous matter in the atmospheres of massive stars, sustaining strong winds and mass loss rates. Not only is this critical for the evolution of such stars, it also provides us with diagnostic UV/optical spectral lines for the determination of mass loss rates,

A. Karastergiou, S. Johnston, M. Kramer

We investigate circular polarization in pulsar radio emission through simultaneous observations of PSR B1133+16 at two frequencies. In particular, we investigate the association of the handedness of circular polarization with the orthogonal polarization mode phenomenon at two different frequencies. We find the association to be significant across the pulse f

Yoko Funato, Junichiro Makino, Piet Hut, Eiichiro Kokubo

Recent observations (Burnes et al 2002,Veillet et al 2002, Margot et al 2002a) have revealed an unexpectedly high binary fraction among the Trans-Neptunian Objects (TNOs) that populate the Kuiper Belt. The TNO binaries are strikingly different from asteroid binaries in four respects (Veillet et al 2002): their frequency is an order of magnitude larger, the m

Thomas Vojta

We show that phase transitions in Ising systems with planar defects, i.e., disorder perfectly correlated in two dimensions are destroyed by smearing. This is caused by effects similar to but stronger than the Griffiths phenomena: Exponentially rare spatial regions can develop true static long-range order even when the bulk system is still in its disordered p

I. A. Pshenichnov, B. L. Berman, W. J. Briscoe, C. Cetina

We have calculated the fission probabilities for 237-Np, 233,235,238-U, 232-Th, and nat-Pb following the absorption of photons with energies from 68 MeV to 3.77 GeV using the RELDIS Monte-Carlo code. This code implements the cascade-evaporation-fission model of intermediate-energy photonuclear reactions. It includes multiparticle production in photoreactions

N. Mirabal, J. P. Halpern, Ryan Chornock, Alexei V. Filippenko

The rapid localization of GRB 021004 by the HETE-2 satellite allowed nearly continuous monitoring of its early optical afterglow decay, as well as high-quality optical spectra that determined a redshift of z3=2.328 for its host galaxy, an active starburst galaxy with strong Lyman-alpha emission and several absorption lines. Spectral observations show multipl

Andrei G. Terekidi, Jurij W. Darewych

We present a variational method for deriving relativistic two-fermion wave equations in a Hamiltonian formulation of QED. A reformulation of QED is performed, in which covariant Green functions are used to solve for the electromagnetic field in terms of the fermion fields. The resulting modified Hamiltonian contains the photon propagator directly. The reform

C. C. Barros

In the study of CP violation signals in $Ø\toπΞ$ nonleptonic decays, the strong $J$=3/2 $P$ and $D$ phase shifts for the $πΞ$ final-state interactions are needed. These phases are calculated using an effective Lagrangian model, including $Ξ$, $Ξ^*$(1530), $ρ$ and the $σ$-term, in the intermediate states. The $σ$-term is calculated in terms of the scalar form

Fabrizio Gabbiani, Andrei I. Onishchenko, Alexey A. Petrov

Lifetime differences of heavy hadrons can be consistently computed in heavy-quark expansion. The leading effects appear through spectator interactions at order 1/m_b^3. We compute a well-defined subset of 1/m_b^4 corrections to the lifetime ratio of Lambda_b baryon and B_d meson. We find that these corrections are large and should be taken into account in th

Ofer Aharony, Oliver DeWolfe, Daniel Z. Freedman, Andreas Karch

Gravity may be "locally localized" over a wide range of length scales on a d-dimensional anti-de Sitter (AdS) brane living inside AdS_{d+1}. In this paper we examine this phenomenon from the point of view of the holographic dual "defect conformal field theory". The mode expansion of bulk fields on the gravity side is shown to be precisely dua

Zoran Skoda

Families of Perelomov coherent states are defined axiomatically in the context of unitary representations of Hopf algebras possessing a Haar integral. A global geometric picture involving locally trivial noncommutative fibre bundles is involved in the construction. A noncommutative resolution of identity formula is proved in that setup. Examples come from qu

Scott A. Caveny, Richard A. Matzner

This work establishes critical phenomena in the topological transition of black hole coalescence. We describe and validate a computational front tracking event horizon solver, developed for generic studies of the black hole coalescence problem. We then apply this to the Kastor - Traschen axisymmetric analytic solution of the extremal Maxwell - Einstein black

Kiyoshi Igusa, Michael Kleber

It is known that the combinatorial classes in the cohomology of the mapping class group of punctures surfaces defined by Witten and Kontsevich are polynomials in the adjusted Miller-Morita-Mumford classes. The leading coefficient was computed in [Kiyoshi Igusa: Algebr. Geom. Topol. 4 (2004) 473-520]. The next coefficient was computed in [Kiyoshi Igusa: math.

J. H. Knapen, R. S. de Jong, S. Stedman, D. M. Bramich

We present near-infrared imaging of a sample of 57 relatively large, Northern spiral galaxies with low inclination. After describing the selection criteria and some of the basic properties of the sample, we give a detailed description of the data collection and reduction procedures. The K_s lambda=2.2 micron images cover most of the disk for all galaxies, wi

E. S. Caixeiro, J. L. González, E. V. L. de Mello

We perform calculations to obtain the $H_{c2}$ curve of high temperature superconductors (HTSC). We consider explicitly the fact that the HTSC possess intrinsic inhomogeneities by taking into account a non uniform charge density $ρ(r)$. The transition to a coherent superconducting phase at a critical temperature $T_c$ corresponds to a percolation threshold a

S. Tamaryan, D. H. Tchrakian

A solution to the BI action describing an expanded D3-brane is considered. The configuration is not supersymmetric but is supported against collapse by the Poynting vector. In the uniform magnetic field limit, the brane magnetic charge grows without limit while the energy and the radius of the brane remain finite. In this limit the brane consists of a large

Soo-Jong Rey, Jung-Tay Yee

We study exclusive scattering of `hadrons' at high energy and fixed angle in (nonconformal) noncommutative gauge theories. Via gauge-string duality, we show that the noncommutativity renders the scattering soft, leading to exponential suppression. The result fits with the picture that, in noncommutative gauge theory, fundamental partons consist of extrem

P. Huber, M. Lindner, T. Schwetz, W. Winter

We present a detailed quantitative discussion of the measurement of the leptonic mixing angle $\sin^2 2 θ_{13}$ with a future reactor neutrino oscillation experiment consisting of a near and far detector. We perform a thorough analysis of the impact of various systematical errors and compare the resulting physics potential to the one of planned first-generat

P. Süle

The correlation between the condensation energy and the critical temperature is studied within a charge ordered superlattice bilayer model in which pairing is supported by inter-layer Coulomb energy gain (potential energy driven superconductivity).The 2D pair-condensate can be characterized by a charge ordered state with a "checkerboard" like pattern

N. Tetradis

We study the qualitative features of the QCD phase diagram in the context of the linear quark-meson model with two flavours, using the exact renormalization group. We identify the universality classes of the second-order phase transitions and calculate critical exponents. In the absence of explicit chiral-symmetry breaking through the current quark masses, w

Boris Konopelchenko, Antonio Moro

Recently proposed quasi-classical DBAR-dressing method provides a systematic approach to study the weakly dispersive limit of integrable systems. We apply the quasi-classical DBAR-dressing method to describe dispersive corrections of any order. We show how calculate the DBAR problems at any order for a rather general class of integrable systems, presenting e

K. A. Pounds, J. N. Reeves, A. R. King, K. L. Page

We report on the analysis of a ~60 ksec XMM observation of the bright, narrow emission line quasar PG 1211+143. Absorption lines are seen in both EPIC and RGS spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionised outflow velocity of ~24000 km s^-1. The highest energy lines require a column d

J. Bermuth, P. Merle, C. C. Carasco, D. Baumann

The charge form factor of the neutron has been determined from asymmetries measured in quasi--elastic pol.3He(pol e,e'n) at a momentum transfer of 0.67(GeV/c)^2. In addition, the target analyzing power, A_y^o, has been measured to study effects of final state interactions and meson exchange currents.

E. M. Bertin, J. -P. Bouchaud

We investigate the behaviour of the response function in the one dimensional trap model using scaling arguments that we confirm by numerical simulations. We study the average position of the random walk at time tw+t given that a small bias h is applied at time tw. Several scaling regimes are found, depending on the relative values of t, tw and h. Comparison

Adel Bilal, Steffen Metzger

When M-theory is compactified on G_2-holonomy manifolds with conical singularities, charged chiral fermions are present and the low-energy four-dimensional theory is potentially anomalous. We reconsider the issue of anomaly cancellation, first studied by Witten. We propose a mechanism that provides local cancellation of all gauge and mixed gauge-gravitationa

Frank Ott, Erik Schnetter

We introduce a modified SPH approach that is based on discretising the particle density instead of the mass density. This approach makes it possible to use SPH particles with very different masses to simulate multi-phase flows with large differences in mass density between the phases. We test our formulation with a simple advection problem, with sound waves

D. J. Pinfield, P. D. Dobbie, R. F. Jameson, I. A. Steele

We present near infrared J-, H- and K-band photometry and optical spectroscopy of low-mass star and brown dwarf (BD) candidates in the Pleiades and Praesepe open clusters. We find that Pleiades stars with K=10.5--13 are rather redder than the NextGen isochrones. We also identify this effect amongst alphaPer sources from the literature, but find no evidence o

Nobuyoshi Ohta

We point out that the recently proposed model of a flat 4-dimensional universe with accelerated expansion in string/M-theory is a special case of time-dependent solutions that the author found under the name of ``S-branes.'' We also show that similar accelerating models can be obtained from S-branes if the internal space is chosen to be hyperbolic or

D. A. S. Fraser, N. Reid, A. C. M. Wong

The estimation of signal frequency count in the presence of background noise has had much discussion in the recent physics literature, and Mandelkern [1] brings the central issues to the statistical community, leading in turn to extensive discussion by statisticians. The primary focus however in [1] and the accompanying discussion is on the construction of a

Simon Portegies Zwart, Steve McMillan, Ortwin Gerhard

We use direct N-body simulations to study the inspiral and internal evolution of dense star clusters near the Galactic center. These clusters sink toward the center due to dynamical friction with the stellar background, and may go into core collapse before being disrupted by the Galactic tidal field. If a cluster reaches core collapse before disruption, its

A. Mercurio, M. Massarotti, P. Merluzzi, M. Girardi

We derive the luminosity functions in three bands (BVR) for the rich galaxy cluster ABCG 209 at z=0.21. The data cover an area of ~78 arcmin^2 in the B and R bands, while a mosaic of three pointings was obtained in the V band, covering an area of approximately 160 arcmin^2. The galaxy sample is complete to B = 22.8 (N_gal = 339), V = 22.5 (N_gal = 1078) and

Qing Jun Zhang, Chong Sheng Li, Jian Jun Liu, Li Gang Jin

We investigate the spin correlations in top quark pair production near threshold at the $ e^- e^+ $ linear collider. Comparing with the results above the threshold region, we find that near the threshold region the off-diagonal basis, the optimized decomposition of the top quark spins above the threshold region, does not exist, and the beamline basis is the

Mohammad R. Garousi

We show that the on-shell S-matrix elements of four open string massless scalars, two scalars and two tachyons, and four open string tachyons in the super string theory can be written in a unique form. We then propose an off-shell extension for the S-matrix element of four scalars which is consistent, in the low energy limit, with the Dirac-Born-Infeld effec

Dong Lai, Wynn C. G. Ho

In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein like resonance across which a X-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to an unique

Adilson E. Motter, Takashi Nishikawa, Ying-Cheng Lai

The characterization of large-scale structural organization of social networks is an important interdisciplinary problem. We show, by using scaling analysis and numerical computation, that the following factors are relevant for models of social networks: the correlation between friendship ties among people and the position of their social groups, as well as

Mizue Honda, Satoru Kaneko, Morimitsu Tanimoto

We have discussed predictions of $|U_{e3}|$ and $J_{CP}$ in the framework of the neutrino mass matrix with two zeros. In the case of the best fit values of $\tan^2θ_{12}$, $\tan^2θ_{23}$, $Δm^2_{\rm sun}$ and $Δm_{\rm atm}^2$, the prediction of $|U_{e3}|$ is $0.11\sim 0.14$. The lower bound of $|U_{e3}|$ is 0.05, which depends on $\tanθ_{12}$ and $\tanθ_{23}

Kenji Hotta

In order to study the thermodynamic properties of brane-antibrane systems in the toroidal background, we compute the finite temperature effective potential of tachyon T in this system on the basis of boundary string field theory. We first consider the case that all the radii of the target space torus are about the string scale. If the Dp-antiDp pair is exten

Lenhard Ng

We present a topological interpretation of knot and braid contact homology in degree zero, in terms of cords and skein relations. This interpretation allows us to extend the knot invariant to embedded graphs and higher-dimensional knots. We calculate the knot invariant for two-bridge knots and relate it to double branched covers for general knots. In the app

Andrzej Grudka, Antoni Wojcik

A new scheme of quantum coding is presented. The scheme concerns the quantum states to which Schumacher's compression does not apply. It is shown that two qubits can be encoded in a single qutrit in such a way that one can faithfully reconstruct the state of one qubit. Decision on which of these two qubits is to be reconstructed can be made long after th

Richard Jozsa, Masato Koashi, Noah Linden, Sandu Popescu

Bipartite entanglement is one of the fundamental quantifiable resources of quantum information theory. We propose a new application of this resource to the theory of quantum measurements. According to Naimark's theorem any rank 1 generalised measurement (POVM) M may be represented as a von Neumann measurement in an extended (tensor product) space of the

Lorenza Viola, Emanuel Knill

We establish conditions under which the experimental verification of quantum error-correcting behavior against a linear set of error operators $\ce$ suffices for the verification of noiseless subsystems of an error algebra $\ca$ contained in $\ce$. From a practical standpoint, our results imply that the verification of a noiseless subsystem need not require

Mitja Perus, Horst Bischof

A simulated Hopfield-type neural-net-like model, which is realizable using quantum holography, is proposed for quantum associative memory and pattern recognition.

Donald H. Galvan

To get insight into the electronic properties of PrFe4P12 skutterudite, band electronic structure calculations, Total and Projected Density of States, Crystal Orbital Overlap Population and Mulliken Population Analysis were performed. The energy bands yield a semi metallic behavior with a direct gap (at gamma) of 0.02 eV. Total and Projected Density of State

J. K. Black, P. Deines-Jones, S. E. Ready, R. A. Street

We report the first results from an X-ray polarimeter with a micropattern gas proportional counter using an amorphous silicon active matrix readout. With 100% polarized X-rays at 4.5 keV, we obtain a modulation factor of 0.33 +/- 0.03, confirming previous reports of the high polarization sensitivity of a finely segmented pixel proportional counter. The detec

G. A. Geloni, E. L. Saldin, E. A. Schneidmiller, M. V. Yurkov

In this paper we discuss a method for nondestructive measurements of the longitudinal profile of sub-picosecond electron bunches for X-Ray Free Electron Lasers (XFELs). The method is based on the detection of the Coherent Synchrotron Radiation (CSR) spectrum produced by a bunch passing a dipole magnet system. This work also contains a systematic treatment of

Enrique Ordaz Romay

At present, whenever we work in newtonian mechanics we consider momentum to be a three-dimensional vector or a 4-dimensional one when we work in relativistic mechanics. However, this mathematical vector model has barely 200 years and its complete installation in the physics is hardly more than 100 years old. In classical mechanics, based on point particles w

Yuri A. Rylov

One calls attention to the fact that the stochastic physical systems are not random completely. They have both random and regular components of their evolution. Dynamic system is considered to be a special case of physical system with vanishing stochastic component of evolution. Mathematical technique for description of regular evolution component of physica

Roelof Bijker

The phenomenom of emerging regular spectral features from random interactions is addressed in the context of the interacting boson model. A mean-field analysis links different regions of the parameter space with definite geometric shapes. The results provide a clear and transparent interpretation of the high degree of order that has been observed before in n

G. C. Hillhouse, J. Mano, S. M. Wyngaardt, B. I. S. van der Ventel

Within the framework of the relativistic distorted wave impulse approximation (DWIA), we investigate the sensitivity of complete sets of polarization transfer observables for exclusive proton knockout from the 3s$_{1/2}$, 2d$_{3/2}$ and 2d$_{5/2}$ states in $^{208}$Pb, at an incident laboratory kinetic energy of 202 MeV, and for coincident coplanar scatterin

Robert K. Murawski

In this paper, the familiar problems of free-fall motion and simple harmonic motion (SHM) are combined. The novel composite system passes from regular to chaotic behavior for increasing values of energy $E$. This system is a suitable example to introduce undergraduates to some of the concepts of dynamical chaos theory.

Adam Lipowski, Ioana Bena, Michel Droz, Antonio L. Ferreira

We study synchronization of random one-dimensional linear maps for which the Lyapunov exponent can be calculated exactly. Certain aspects of the dynamics of these maps are explained using their relation with a random walk. We confirm that the Lyapunov exponent changes sign at the complete synchronization transition. We also consider partial synchronization o

T. Gilbert, J. R. Dorfman

We discuss a two-parameter family of maps that generalize piecewise linear, expanding maps of the circle. One parameter measures the effect of a non-linearity which bends the branches of the linear map. The second parameter rotates points by a fixed angle. For small values of the nonlinearity parameter, we compute the invariant measure and show that it has a

G. Iovane, F. Passarella

The aim of this paper is to study the spatial behaviour of the solutions to the boundary-final value problems associated with the linear theory of elastic materials with voids. More precisely the present study is devoted to porous materials with a memory effect for the intrinsic equilibrated body forces. An appropriate time-weighted volume measure is associa

Manfred Requardt

With the help of a smooth scaling and coarse-graining approach of observables, developed recently by us in the context of so-called fluctuation operators (inspired by prior work of Verbeure et al) we perform a rigorous renormalisation group analysis of the critical regime. The approach is quite general, encompassing classical, quantum, discrete and continuou

Sever Silvestru Dragomir

Some new Gruss type inequalities in inner product spaces and applications for integrals are given.

Pavel Etingof, Shlomo Gelaki

In this paper we contribute to the classification of Hopf algebras of dimension pq, where p,q are distinct prime numbers. More precisely, we prove that if p and q are odd primes with p<q<2p+3, then any complex Hopf algebra of dimension pq is semisimple and hence isomorphic to either a group algebra or to the dual of a group algebra by the previous works math

A. H. Zemanian

A criterion is established for the transitivity of connectedness in a transfinite graph. Its proof is much shorter than a prior argument published previously for that criterion.

L. Yu. Glebsky, C. J. Rubio

A (partial) Latin square is a table of multiplication of a (partial) quasigroup. Multiplication of a (partial) quasigroup may be considered as a set of triples. We give a necessary and sufficient condition when a set of triples is a quotient of a (partial) Latin square.