August 2003 arXiv papers — page 8

S. L. Bud'ko, E. Q. T. Morosan, P. C. Canfield

Detailed anisotropic resistivity and heat capacity measurements down to ~0.4 K and up to 140 kOe are reported for a single crystalline YbAgGe. Based on these data YbAgGe, a member of the hexagonal RAgGe series, can be classified as new, stoichiometric heavy fermion compound with two magnetic ordering temperatures below 1 K and field-induced non-Fermi-liquid

A. K. Aringazin, Yu. Dahnovsky, V. D. Krevchik, M. B. Semenov

Two-particle tunneling in synchronous and asynchronous regimes is studied in the framework of dissipative quantum tunneling. We show that the use of the proposed model is justified by a comparison with realistic potential energy surfaces of porphyrin and experimental dependence of the reaction rate on temperature. The critical temperature T_c corresponding t

Sergio Caracciolo, Andrea Sportiello

We introduce a general class of statistical-mechanics models, taking values in an abelian group, which includes examples of both spin and gauge models, both ordered and disordered. The model is described by a set of ``variables'' and a set of ``interactions''. A Gibbs factor is associated to each variable and to each interaction. We introduce

Giorgio Parisi

In this paper we present a backtracking version of the survey propagation algorithm. We show that the introduction of the simplest form of backtracking greatly improves the ability of the original survey propagation algorithm in solving difficult random problems near the sat-unsat transition.

Igor I. Smolyaninov

Zero-point energy of surface plasmon modes of mesoscopic metal samples in an external magnetic field has been considered. The magnetic response of plasmon vacuum has shown to be diamagnetic. In thin films this surface vacuum diamagnetism is at least of the same order of magnitude as the magnetism of the bulk electrons. Thus, a novel type of magnetism shown b

K. Ishida, Y. Ihara, Y. Maeno, C. Michioka

Co NQR studies were performed in recently discovered superconductor Na$_x$CoO$_2$$\cdot y$H$_2$O to investigate physical properties in the superconducting (SC) and normal states. Two samples from the same Na$_x$CoO$_2$ were examined, SC bilayer-hydrate sample with $T_c \sim 4.7$ K and non-SC monolayer-hydrate sample. From the measurement of nuclear-spin latt

Leonardo Civale, Alejandro V. Silhanek, Gabriela Pasquini

We explore in detail the angular dependent vortex dynamics in type II superconductors with aligned columnar defects introduced by irradiation with very energetic heavy-ions. We use dc magnetization measurements deep in the vortex solid phase, and ac susceptibility near the solid-liquid transition. We show that aligned columnar defects are an excellent tool t

J. Hopkinson, K. Le Hur

We investigate the physics of frustrated 3-leg Hubbard ladders in the band limit, when hopping across the ladder's rungs (t$_{\perp}$) is of the same order as hopping along them (t) much greater than the onsite Coulomb repulsion (U). We show that this model exhibits a striking electron-hole asymmetry close to half-filling: the hole-doped system at low te

J. Balakrishnan

A path-integral formalism is proposed for studying the dynamical evolution in time of patterns in an artificial neural network in the presence of noise. An effective cost function is constructed which determines the unique global minimum of the neural network system. The perturbative method discussed also provides a way for determining the storage capacity o

R G Mani, W B Johnson, V. Narayanamurti

The application of the quantum mechanical properties of physical systems to realize novel computational schemes and innovative device functions have been topics of recent interest. Proposals for associated devices are to be found in diverse branches of physics. Here, we are concerned with the experimental realization of some elements needed for quantum infor

D. V. Bulaev, V. A. Geyler, V. A. Margulis

The effect of the surface curvature on the magnetic moment and persistent currents in two-dimensional (2D) quantum rings and dots is investigated. It is shown that the surface curvature decreases the spacing between neighboring maxima of de Haas -- van Alphen (dHvA) type oscillations of the magnetic moment of a ring and decreases the amplitude and period of

S. -C. Lee, A. Wacker

In a recent Letter [Appl. Phys. Lett. 82, 1015 (2003)], Williams et al. reported the development of a terahertz quantum cascade laser operating at 3.4 THz or 14.2 meV. We have calculated and analyzed the gain spectra of the quantum cascade structure described in their work, and in addition to gain at the reported lasing energy of ~= 14 meV, we have discovere

Sadhan K. Adhikari

Using the axially-symmetric time-dependent mean-field Gross-Pitaevskii equation we study the Josephson oscillation in a repulsive Bose-Einstein condensate trapped by a harmonic plus an one-dimensional optical-lattice potential to describe the experiments by Cataliotti et. al. [Science 293 (2001) 843, New J. Phys. 5 (2003) 71.1]. After a study of the formatio

M. R. Schaapman, U. Zeitler, P. C. M. Christianen, J. C. Maan

We have measured the magnetization of a dual-subband two-dimensional electron gas, confined in a GaAs/AlGaAs heterojunction. In contrast to two-dimensional electron gases with a single subband, we observe non-1/B-periodic, triangularly shaped oscillations of the magnetization with an amplitude significantly less than $1 μ_{\mathrm{B}}^*$ per electron. All th

Nguyen Hoa Hong, Joe Sakai, W. Prellier, Awatef Hassini

Pure rutile Co-doped TiO$_2$ films were fabricated successfully by the conventional pulsed laser deposition technique on silicon substrates from a ceramic target. Under the right fabrication conditions, Co concentration in the films could be almost the same as in the synthesized target, and films under various conditions all are ferromagnetic well above room

I. Shvarchuck, Ch. Buggle, D. S. Petrov, M. Kemmann

We study hydrodynamic behavior in expanding thermal clouds of Rb-87 released from an elongated trap. At our highest densities the mean free path is smaller than the radial size of the cloud. After release the clouds expand anisotropically. The cloud temperature drops by as much as 30%. This is attributed to isentropic cooling during the early stages of the e

N. Katz, R. Ozeri, E. Rowen, E. Gershnabel

We report on a series of measurements of decoherence and wavepacket dephasing between two colliding, strongly coupled, identical Bose-Einstein condensates. We measure, in the strong excitation regime, a suppression of the mean-field shift, compared to the shift which is observed for a weak excitation. This suppression is explained by applying the Gross-Pitae

A. S. Alexandrov

A single vortex in the charged Bose gas (CBG) has a charged core and its profile different from the vortex in neutral and BCS superfluids. Lower and upper critical fields of CBG are discussed. The unusual resistive upper critical field, Hc2(T), of many cuprates and a few other unconventional superconductors is described as the Bose-Einstein condensation fiel

S. Bednarek, J. Adamowski, B. Szafran

We investigate the problem of the electron interacting with the charge induced on the metal or dielectric surface. We show that the interaction between the electron and the induced surface charge leads to the lateral confinement of the electron. As a result the electron propagates parallel to the surface not as a plane wave but as a wave packet of a Gaussian

A. S. Alexandrov

There is a growing understanding that transport properties of complex oxides and individual molecules are dominated by polaron physics. In superconducting oxides the long-range Froehlich and short-range Jahn-Teller electron-phonon interactions bind carriers into real space pairs - small bipolarons with surprisingly low mass but sufficient binding energy, whi

A. N. Gorban, P. A. Gorban, I. V. Karlin

A toolbox for the development and reduction of the dynamical models of nonequilibrium systems is presented. The main components of this toolbox are: Legendre integrators, dynamical postprocessing, and thermodynamic projector. Thermodynamic projector is the tool to transform almost arbitrary anzatz to a thermodynamically consistent model, the postprocessing i

S. N. Klimin, V. M. Fomin, J. Tempere, I. F. Silvera

In multielectron bubbles, the electrons form an effectively two-dimensional layer at the inner surface of the bubble in helium. The modes of oscillation of the bubble surface (the ripplons) are influenced by the charge redistribution of the electrons along the surface. The dispersion relation for these charge redistribution modes (`longitudinal plasmons'

S. N. Klimin, V. M. Fomin, F. Brosens, J. T. Devreese

The method for calculating the ground-state energy and the optical conductivity spectra is developed for a system of a finite number of interacting arbitrary-coupling polarons in a spherical quantum dot with a parabolic confinement potential. The path-integral formalism for identical particles is used in order to take into account the fermion statistics. Usi

M. D. Croitoru, V. N. Gladilin, V. M. Fomin, J. T. Devreese

An approach is developed for the determination of the current flowing through a nanosize silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors (MOSFET). The quantum mechanical features of the electron transport are extracted from the numerical solution of the quantum Liouville equation in the Wigner function representation. Accounting

J. T. Devreese, V. M. Fomin, E. P. Pokatilov, V. N. Gladilin

It is shown that in many cases an adequate description of optical spectra of semiconductor quantum dots requires a treatment beyond the commonly used adiabatic approximation. We have developed a theory of phonon-assisted optical transitions in semiconductor quantum dots, which takes into account non-adiabaticity of the exciton-phonon system. Effects of non-a

H. -W. Hammer

Effective field theories exploit a separation of scales in physical systems in order to perform systematically improvable, model-independent calculations. They are ideally suited to describe universal aspects of a wide range of physical systems. I will discuss recent applications of effective field theory to cold atomic and molecular few-body systems with la

Ryo Maezawa, Shiro Kashimoto, Tsutomu Ishimasa

Starting from the Zn17Sc3 cubic approximant, new quasicrystal alloys were searched by replacement of Zn with transition elements, T. In the cases of T=Mn, Fe, Co and Ni, new icosahedral quasicrystals are formed in as-cast alloys as major phases at the alloy compositions of Zn75T10Sc15. All these quasicrystals belong to a primitive type, and have 6-dimensiona

Tsutomu Ishimasa, Kei Oyamda, Yasuomi Arichika, Eiji Nishibori

A structure analysis of Zn-Mg-Ho icosahedral quasicrystal was carried out by the powder X-ray diffraction method using synchrotron radiation (Lambda=0.73490 A) at SPring-8. The intensity distribution was analyzed by the Rietveld method modified for an icosahedral quasicrystal, in which simplified models were assumed: ellipsoid and spherical windows were assu

Tsutomu Ishimasa, Yasushi Kaneko, Hiroshi Kaneko

Structural studies on the icosahedral quasicrystals in Zn-Mg-Sc, Cu-Ga-Mg-Sc, and Zn-Mg-Ti alloys as well as their corresponding 1/1 cubic approximants, have revealed that these quasicrystals belong to a new structural group similar to Cd-based quasicrystals. This group is characterized by a triple-shell icosahedral cluster different from both Mackay- and Be

Hiroaki Ikeda, Yunori Nisikawa, Kosaku Yamada

Stimulated by the recent finding of Na$_{0.35}$CoO$_2$.1.3H$_2$O superconductor, we investigate superconducting instabilities on a 2D triangular lattice in the repulsive Hubbard model. Using the third-order perturbation expansion with respect to the on-site repulsion $U$, we evaluate the linearized Dyson-Gor'kov equation. We find that an $f$-wave spin-tr

S. N. Dorogovtsev

We discuss a simple method of constructing correlated random networks, which was recently proposed by M. Bogu~n'a and R. Pastor-Satorras (cond-mat/0306072). The result of this construction procedure is a sparse network whose degree--degree distribution asymptotically approaches a given function at large degrees. We argue that this convergence is possible

U. Buchenau

The glass transition is described in terms of thermally activated local structural rearrangements, the secondary relaxations of the glass phase. The interaction between these secondary relaxations leads to a much faster and much more dramatic breakdown of the shear modulus than without interaction, thus creating the impression of a separate primary process w

S. I. Ipatov, J. C. Mather, P. A. Taylor

We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all aste

S. I. Ipatov, J. C. Mather

The orbital evolution of about 20000 Jupiter-crossing objects and 1500 resonant asteroids under the gravitational influence of planets was investigated. The rate of their collisions with the terrestrial planets was estimated by computing the probabilities of collisions based on random-phase approximations and the orbital elements sampled with a 500 yr step.

N. Kameswara Rao, David L. Lambert

Photometry and low-resolution spectroscopy have added V2552 Oph to the rare class of R Coronae Borealis variables. We confirm this classification of V2552 Oph through a comparison of our high-resolution optical spectrum of this star and that of R CrB and other F-type members of the class. We show that V2552 Oph most closely resembles Y Mus and FH Sct, stars

Gerry Skinner, Peter von Ballmoos, Neil Gehrels, John Krizmanic

Phase Fresnel lenses have the same imaging properties as zone plates, but with the possibility of concentrating all of the incident power into the primary focus, increasing the maximum theoretical efficiency from 11% to close to 100%. For X-rays, and in particular for gamma-rays, large, diffraction-limited phase Fresnel lenses can be made relatively easily.

G. K. Skinner, P. H. Connell

A key tool in the package of software available for the analysis of data from the SPI spectrometer of Integral is the SPIROS system developed at the University of Birmingham. Although intended primarily for the analysis of point sources and for the extraction of spectral information, SPIROS has many additional capabilities. The software is described with par

Donald P. Schneider, Xiaohui Fan, Patrick B. Hall, Sebastian Jester

We present the second edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of 16713 objects in the SDSS First Data Release (DR1) that have luminosities larger than M_i=-22 (H_0=70 km/s, Omega_M=0.3, Omega_Lambda=0.7), have at least one emission line with FWHM larger than 1000 km/s, and have highly reliable redshifts. The area c

Miguel Mostafa

Major uncertainties in the fluorescence energy measurement come from the precision of various atmospheric transmission, air Cerenkov subtraction, light multiple-scattering and cloud corrections. The Auger program for atmospheric monitoring, designed to measure these corrections and to minimize these uncertainties, is summarized in this paper.

Sergio del Campo, Patricio Salgado

We describe an accelerating universe model in the context of a scalar-tensor theory. This model is intrinsically closed, and is filled with quintessence-like scalar field components, in addition to the Cold Dark Matter component. With a background geometry specified by the Friedman-Robertson-Walker metric, we establish conditions under which this closed cosm

Tracy Webb, Simon Lilly, David Clements, Steve Eales

We present the multi-wavelength identifications for 23 sources in the Canada-UK Deep Submillimeter Survey (CUDSS) 14h field. The identifications have been selected on the basis of radio and near-infrared data and we argue that, to our observational limits, both are effective at selecting the correct counterparts of the SCUBA sources. We discuss the propertie

K. K. Knudsen, P. P. van der Werf, W. Jaffe

We present the discovery of a dusty quasar, SMMJ04135+10277, located behind the galaxy cluster Abell 478. The quasar was discovered as the brightest source in a submillimetre survey of high redshift galaxies lensed by foreground rich clusters of galaxies in a project aimed at studying the cosmic star formation history of dusty galaxies. With submm fluxes of

M. Castellani, F. Caputo, V. Castellani

In this paper we revisit observational data concerning RR Lyrae stars in Galactic globular clusters, presenting frequency histograms of fundamentalized periods for the 32 clusters having more than 12 pulsators with well recognized period and pulsation mode. One finds that the range of fundamentalized periods covered by the variables in a given cluster remain

Alexander V. Halevin

In this work we have investigated short time-scale variability of NGC 4051 and NGC 4388. The quasi-steady QPO's time scale of 3920$\pm$17 sec was detected for NGC 4051. For the case of NGC 4388 we investigated rapid variability of the parameters of spectral models. To obtain these results, a new "Moving Fit" method for processing of the trailed X

Mohsen Nejad-Asghar, Jamshid Ghanbari

Thermal instability is one of the most important processes in the formation of clumpy substructure in magnetic molecular clouds. On the other hand, ambipolar diffusion, or ion-neutral friction, has long been thought to be an important energy dissipation mechanism in these clouds. Thus, we would interested to investigate the effect of ambipolar diffusion on t

D. Reimers, R. Baade, R. Quast, S. A. Levshakov

A new molecular hydrogen cloud is found in the sub-damped Ly-alpha absorber [log N(HI)=19.88+/-0.05] at the redshift z=1.15 toward the bright quasar HE0515-4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2 are identified in the UV spectrum of this quasar obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the

M. Riello, S. Cassisi, G. Piotto, A. Recio-Blanco

We present observational estimates of the magnitude difference between the luminosity function RGB bump and the HB (Delta(bump-zahb)), and of star counts in the bump region (R_bump), for a sample of 54 Galactic globular clusters (GCs) observed by the HST. The large sample of stars resolved in each cluster, and the high photometric accuracy of the data allowe

L. C. Popovic, E. G. Mediavilla, E. Bon, N. Stanic

We have studied the Ly-al, Hbeta, Halpha and Mg II2798 line profiles of the Seyfert 1 galaxy III Zw 2. The shapes of these broad emission lines show evidence of a multicomponent origin and also features which may be identified as the peaks due to a rotating disk. We have proposed a two-component Broad Line Region (BLR) model consisting of an inner Keplerian

V. V. Kovtyukh, C. Soubiran, S. I. Belik, N. I. Gorlova

Line depth ratios measured on high resolution (R=42000), high S/N echelle spectra are used for the determination of precise effective temperatures of 181 F,G,K Main Sequence stars with about solar metallicity (-0.5 < [Fe/H] < +0.5). A set of 105 relations is obtained which rely Teff on ratios of the strengths of lines with high and low excitation potentials,

Piera Luisa Ghia

Three months of data taken by the Engineering Array Surface Detector of the Pierre Auger Observatory have been analyzed with the aim of setting a procedure for the study of showers at E_0 ~ 10^18 eV. We present the results, concerning: (i) the selection procedure and the check of its efficiency; (ii) the event rate and its stability; (iii) the characteristic

Stefano Argiro

The Pierre Auger Observatory is designed to elucidate the origin and nature of Ultra High Energy Cosmic Rays using a hybrid detection technique. A first run of data taking with a prototype version of both detectors (the so called Engineering Array) took place in 2001-2002, allowing the Collaboration to evaluate the performance of the two detector systems and

A. Boccaletti, G. Chauvin, A. -M. Lagrange, F. Marchis

This article presents coronagraphic images of the low-mass companion to the star HR 7672 observed at the Palomar 200 inch telescope and first detected at Gemini and Keck in the K band by \citet{liu02}. We obtained additional photometry in $J$($1.2μm$), $H$($1.6μm$) and $K_s$ ($2.2μm$) bands to cover the full near-IR domain and hence to further constrain the

Alon Retter, Timothy R. Bedding, Derek L. Buzasi, Hans Kjeldsen

The value of the mode lifetime given in the first paragraph of the Discussion should be divided by 2pi and is therefore 2.0 days rather than 13 days.

E. Miyata, K. Tamura

We report on a new photon-counting detector possessing unprecedented spatial resolution, moderate spectral resolution and high background-rejection capability for 0.1-100 keV X-rays. It consists of an X-ray charge-coupled device (CCD) and scintillator. The scintillator is directly deposited on the back surface of the X-ray CCD. Low-energy X-rays below 10 keV

S. Shibata, H. Tomatsuri, M. Shimanuki, K. Ssito

An axisymmetric model for the Crab Nebula is constructed to examine the flow dynamics in the nebula. The model is based on that of Kennel and Coroniti (1984), although we assume that the kinetic-energy-dominant wind is confined in an equatorial region. The evolution of the distribution function of the electron-positron plasma flowing out in the nebula is cal

C. C. Cheung, C. Megan Urry, Riccardo Scarpa, Mauro Giavalisco

Multi-band near-infrared images of twelve BL Lacertae objects were obtained with the 2.5m telescope at the Las Campanas Observatory in order to determine the properties of their underlying host galaxies. Resolved emission was clearly detected in eight of the lowest redshift targets (up to z~0.3), and was modeled with a de Vaucouleurs r^{1/4} surface brightne

E. Novais, A. H. Castro Neto

We analyze a quantum computer (QC) design based on nuclear spin qubits in a quasi-one-dimensional (1D) chain of non-Kramers doublet atoms. We explore the use of spatial symmetry breaking to obtain control over the local dynamics of a qubit. We also study the decoherence mechanisms at the single qubit level and the interactions mediated by the magnetic media.

Ludvig Faddeev, Antti J. Niemi, Ulrich Wiedner

The $eta_L(1410)$ component of the $η(1440)$ pseudoscalar has strong affinity for glue. But its mass is incompatible with lattice simulations that predict a much higher value for the $0^{-+}$ glueball. As a consequence it has been suggested that $η_L(1410)$ could signal physics beyond the Standard Model. Here we argue that if glueballs are closed gluonic flu

Ian G. Moss

A new action for eleven dimensional supergravity on a manifold with boundary is presented. The action is a possible low energy limit of $M$-theory. Previous problems with infinite constants in the action are overcome and a new set of boundary conditions relating the behaviour of the supergravity fields to matter fields are obtained. One effect of these bound

Emir Haleva, Nir Ben-Tal, Haim Diamant

We studied the adsorption of a charged protein onto an oppositely charged membrane, composed of mobile phospholipids of differing valence, using a statistical-thermodynamical approach. A two-block model was employed, one block corresponding to the protein-affected region on the membrane, referred to as the adsorption domain, and the other to the unaffected r

Shijun Yoshida, Toshifumi Futamase

We calculate high-order quasinormal modes with large imaginary frequencies for electromagnetic and gravitational perturbations in nearly extremal Schwarzschild-de Sitter spacetimes. Our results show that for low-order quasinormal modes, the analytical approximation formula in the extremal limit derived by Cardoso and Lemos is a quite good approximation for t

A. I. Veselov, M. A. Zubkov

10 D Euclidean quantum gravity is investigated numerically using the dynamical triangulation approach. It has been found that the behavior of the model is similar to that of the lower dimensional models. However, it turns out that there are a few features that are not present in the lower dimensional models.

Tôru Sakai, Kiyomi Okamoto, Kouichi Okunishi, Masahiro Sato

We study, at T=0, the anomalies in the magnetization curve of the S=1 two-leg ladder with frustrated interactions. We focus mainly on the existence of the $M=\Ms/2$ plateau, where $\Ms$ is the saturation magnetization. We use analytical methods (degenerate perturbation theory and non-Abelian bosonization) as well as numerical methods (level spectroscopy and

Wang Lei, Ma Wen-Gan, Hou Hong-Sheng, Zhang Ren-You

We investigate in detail the effects of the R-parity lepton number violation in the minimal supersymmetric standard model (MSSM) on the top-quark pair production via both $e^--e^+$ and $γ-γ$ collision modes at the linear colliders. We find that with the present experimental constrained $\rlap/{R}$ parameters, the effect from $\rlap/{R}$ interactions on the p

Ricardo A. Mosna, Jayme Vaz

We present a tomographic scheme, based on spacetime symmetries, for the reconstruction of the internal degrees of freedom of a Dirac spinor. We discuss the circumstances under which the tomographic group can be taken as SU(2), and how this crucially depends on the choice of the gamma matrix representation. A tomographic reconstruction process based on discre

Ahmad Moshaii, Rasool Sadighi-Bonabi, Mohammad Taeibi-Rahni

Equations of radial motion of a gas bubble in a compressible viscous liquid have been modified to account for compressibility at the bubble boundary. A new bubble boundary equation has been derived, including a new term resulted from liquid compressibility. The influence of this term has been numerically investigated using isothermal-adiabatic model for the

Charles R. Doering, Bruno Eckhardt, Joerg Schumacher

We study the problem of body-force driven shear flows in a plane channel of width l with free-slip boundaries. A mini-max variational problem for upper bounds on the bulk time averaged energy dissipation rate epsilon is derived from the incompressible Navier-Stokes equations with no secondary assumptions. This produces rigorous limits on the power consumptio

Bergthor Hauksson, Jakob Yngvason

We consider the grand canonical pressure for Coulombic matter with nuclear charges $\sim Z$ in a magnetic field $B$ and at nonzero temperature. We prove that its asymptotic limit as $Z\to\infty$ with $B/Z^3\to 0$ can be obtained by minimizing a Thomas-Fermi type pressure functional.

Nguyen T. Thao, C. Sinan Gunturk

This paper has two themes that are intertwined: The first is the dynamics of certain piecewise affine maps on the Euclidean space that arise from a class of analog-to-digital conversion methods called Sigma-Delta quantization. The second is the analysis of reconstruction error associated to each such method. Sigma-Delta quantization generates approximate rep

Riccardo Piergallini, Daniele Zuddas

We construct an orientable ribbon surface F in B^4, which is universal in the following sense: any compact orientable pl 4-manifold having a handle decomposition with 0-, 1- and 2-handles can be represented as a cover of B^4 branched over F.

J. Towe

It is shown that quarks and leptons can couple intrinsically to pure supergravity, preserving for this context the degeneracy of globally supersymmetric vacua, and specifically preserving the vacuum that is characterized by SU(4)XU(1). A fundamental representation of SUSY SU(4)XU(1) is constructed in terms of quarks, and it is demonstrated that the symmetry

Gheorghe Zet

We obtain the Schwarzschild solution based on teleparallel gravity (TG) theory formulated in a space-time with torsion only. The starting point is the Poincar\UNICODE{0xe9} gauge theory (PGT).The general structure of TG and its connection with general relativity (GR) are presented and the Schwarzschild solution is obtained by solving the field equations of T

Andrej Brodnik, Andreas Nilsson

In this paper we present a discrete data structure for reservations of limited resources. A reservation is defined as a tuple consisting of the time interval of when the resource should be reserved, $I_R$, and the amount of the resource that is reserved, $B_R$, formally $R=\{I_R,B_R\}$. The data structure is similar to a segment tree. The maximum spanning in

M. J. Biercuk, N. Mason, C. M. Marcus

Local effects of multiple electrostatic gates placed beneath carbon nanotubes grown by chemical vapor deposition (CVD) are reported. Single-walled carbon nanotubes were grown by CVD from Fe catalyst islands across thin Mo &#34;finger gates&#34; (150 x 10nm). Prior to tube growth, several finger gates were patterned lithogrpahically and subsequently coated wi

Shan-Wen Tsai, P. J. Hirschfeld

A d-wave superconductor with isolated strong non-magnetic impurities should exhibit an upturn in the penetration depth at low temperatures. Here we calculate how an external magnetic field supresses this effect.

Hui Hu, Feng Yuan, Shaojin Qin

In some recent experiments an ultracold gas of $^{40}$K$_2$ (or $^{6}$Li$_2$) molecules has been produced from a degenerate two-component Fermi gas of $^{40}$K (or $^{6}$Li) atoms by adiabatic passage through a Feshbach resonance. The maximum atom-molecule transfer efficiency is reported to be about 50%. We propose a simple microscopic model to characterize

N. Stefanakis

We study the proximity effect in superconductor - metallic or ferromagnetic Aharonov Bohm loop hybrid structures self consistently using the Bogoliubov-deGennes formalism within the two dimensional extended Hubbard model. We calculate the local density of states, the pair amplitude, and persistent currents as a function of several modulation parameters, the

Marco Frasca

Using perturbation theory in the strong coupling regime, that is, the dual Dyson series, and renormalization group techniques to re-sum secular terms, we obtain the perturbation series of the two-level system driven by a sinusoidal field till second order. The third order correction to the energy levels is obtained proving how this correction does not modify

R. Kantowski

The differential equation governing distance-redshift for partially filled-beam optics in pressure-freeFriedmann-Lema\^ıtre-Robertson-Walker Cosmology (FLRW) is shown to be the Lame$^{\prime}$ equation. The distance-redshift, $D(z)$, discussed is appropriate for observations in inhomogeneous cosmologies for which lensing by masses external to the observing b

Wendy L. Freedman, Michael S. Turner

Revolutionary advances in both theory and technology have launched cosmology into its most exciting period of discovery yet. Unanticipated components of the universe have been identified, promising ideas for understanding the basic features of the universe are being tested, and deep connections between physics on the smallest scales and on the largest scales

Michael W Feast, Patricia A Whitelock, Freddy Marang

JHKL observations of the mass-losing carbon Mira variable IRAS 15194-5115 (II Lup) extending over about 18 years are presented and discussed. The pulsation period is 575 days and has remained essentially constant over this time span. The star has undergone an extensive obscuration minimum during this time. This is complex and, like such minima in similar obj

Riccardo Scarpa, Gianni Marconi, Roberto Gilmozzi

New measurements of the velocity dispersion of the globular cluster omega Centauri allow to trace its gravitational potential down to an acceleration of 8e-9 cm/s/s. It is found that the dispersion profile remains flat well inside the tidal radius as soon as the acceleration of gravity approaches a_0, a result that finds its simplest explanation within the c

Yang Li, F. G. Vagizov, V. Goruganti, Joseph H. Ross,

We have used 57Fe Mossbauer spectroscopy and x-ray diffraction to study the magnetic and vibrational properties of FeAl2. FeAl2 is an ordered intermetallic with a large Fe local moment, and a complex crystal structure with site-occupation disorder on some sites. This material exhibits spin-glass freezing below 35 K. From the 57Fe recoilless fraction, we find

Alvin Kiswandhi, Simon Capstick, Steven Dytman

The properties of baryon resonances are extracted from a complicated process of fitting sophisticated, empirical models to data. The reliability of this process comes from the quality of data and the robustness of the models employed. With the large of amount of data coming from recent experiments, this is an excellent time for a study of the model dependenc

Bernard Leong, William Saslaw

We examine the peculiar velocity distribution function of galaxies in cosmological many-body gravitational clustering. Our statistical mechanical approach derives a previous basic assumption and generalizes earlier results to galaxies with haloes. Comparison with the observed peculiar velocity distributions indicates that individual massive galaxies are usua

Malte Henkel, Gunter M. Schütz

The two-time nonequilibrium correlation and response functions in 1D kinetic classical spin systems with non-conserved dynamics and quenched to their zero-temperature critical point are studied. The exact solution of the kinetic Ising model with Glauber dynamics for a wide class of initial states allows for an explicit test of the universality of the non-equ

W. B. Belayev

In induced matter Kaluza-Klein gravity theory the solution of the dynamics equations for the test particle on null path leads to additional force in four-dimensional space-time. We find such force from five-dimensional geodesic line equations and apply this approach to analysis of the asymmetrically warped space-time.

Hisamitsu Mukaida

By adding a linear term to a renormalization-group equation in a system exhibiting infinite-order phase transitions, asymptotic behavior of running coupling constants is derived in an algebraic manner. A benefit of this method is presented explicitly using several examples.

Tomoyuki Yamakami

The complexity class NP is quintessential and ubiquitous in theoretical computer science. Two different approaches have been made to define &#34;Quantum NP,&#34; the quantum analogue of NP: NQP by Adleman, DeMarrais, and Huang, and QMA by Knill, Kitaev, and Watrous. From an operator point of view, NP can be viewed as the result of the exists-operator applied

James P. Finley

For closed-shell systems, the local density approximation (LDA) and the LYP, BLYP, and B3LYP functionals are shown to be compatible with reference-state one-particle density-matrix theory, where this recently introduced formalism is based on Brueckner-orbital theory and an energy functional that includes exact exchange and a non-universal correlation-energy

Arvinder S. Sandhu, G. Ravindra Kumar, S. Sengupta, A. Das

Here we experimentally map the dynamics of electron plasma waves in laser solid interaction. We do time resolved measurements of second harmonic and hard X-ray generation from interaction of intense ($10^{16} W cm^{-2}$, 100 fs, 800nm) laser with a pre-plasma generated on a solid surface. The parameter space explored in this time resolved study includes vari

Steve Zelditch

This is a report for the 2003 Forges Les Eaux PDE conference on recent results with A. Hassell on quantum ergodicity of boundary traces of eigenfunctions on domains with ergodic billiards, and of work in progress with Hassell and Sogge on norms of boundary traces. Related work by Burq, Grieser and Smith-Sogge is also discussed.

Alex J. Feingold

This is an expository introduction to fusion rules for affine Kac-Moody algebras, with major focus on the algorithmic aspects of their computation and the relationship with tensor product decompositions. Many explicit examples are included with figures illustrating the rank 2 cases. New results relating fusion coefficients to tensor product coefficients are

Luis Alberto Sanchez, Jorge Mahecha

Due to the fact that only matter fields have phase, frequently is believed that the gauge principle can induce gauge fields only in quantum systems. But this is not necessary. This paper, of pedagogical scope, presents a classical system constituted by a particle in a classical potential, which is used as a model to illustrate the gauge principle and the spo

Antonio Campos, Roy Maartens, David Matravers, Carlos F. Sopuerta

For a cosmological Randall-Sundrum braneworld with anisotropy, i.e., of Bianchi type, the modified Einstein equations on the brane include components of the five-dimensional Weyl tensor for which there are no evolution equations on the brane. If the bulk field equations are not solved, this Weyl term remains unknown, and many previous studies have simply pre

P. Midodashvili

We present two new solutions to Einstein&#39;s equations in (1+5)-spacetime with a positive bulk cosmological constant. One solution has increasing and another solution decreasing bounded scale function without singularities in the range from the origin r=0 to the radial infinity. For the both solutions it is shown that all local fields are localized near th

Einan Gardi, Matteo Cacciari

We describe a new approach to heavy-quark fragmentation which is based on a resummed perturbative calculation and parametrization of power corrections, concentrating on the z -> 1 limit, where the heavy meson carries a large fraction of the momentum of the initial quark. It is shown that the leading power corrections in this region are controlled by the scal

Dominik Dannheim

A search for anomalous single-top production, ep -> etX, t -> Wb, has been made with the ZEUS detector at HERA using an integrated luminosity of 130 pb^-1. No evidence for top-quark production was found in either the leptonic or the hadronic decay channel of the W boson. The resulting constraints on single-top production via quark-flavour changing neutral cu

Andreas Schaale, Carsten Wulf-Mathies, Soenke Lieberam-Schmidt

In this paper we will derive a new algorithm for Internet searching. The main idea of this algorithm is to extend the existing algorithms by a component, which reflects the interests of the users more than existing methods. The &#34;Vox Populi Algorithm&#34; (VPA) creates a feedback from the users to the content of the search index. The information derived f

Vadim V. Cheianov, M. B. Zvonarev

In this Letter we report exact results on the infrared asymptotics of one-particle dynamical correlation function of the gas of impenetrable spin 1/2 fermions at infinitesimal temperature. The correlation function shows signs of spin-charge separation with scaling behavior in the charge part and exponential decay as a function of the space coordinate in the