November 2001 arXiv papers — page 2

G. Valenti

The study of heavy ion interactions constitutes an important part of the experimental program outlined for the Large Hadron Collider under construction at CERN and expected to be operational by 2006. ALICE is the single detector having the capabilities to explore at the same time most of the characteristics of high energy heavy ion interactions. Specific stu

J. William Gary

The charged particle multiplicities of two- and three-jet events from the reaction e$^+$e$^-$,\to $Z$^0 \to hadrons$ are measured for Z$^0$ decays to light quark (uds) flavors, using the data sample of the OPAL Collaboration at LEP. Using recent theoretical expressions to account for biases from event selection, results corresponding to unbiased gluon jets a

Raimond Snellings

In these proceedings we will present the preliminary identified single particle inclusive spectra, the identified particle elliptic flow and the HBT versus the reaction plane measured with the STAR detector at RHIC. So far none of the theoretical space-time models has been able to describe the combination of these measurements consistently. In order to see i

Z. Fodor, S. D. Katz

We propose a method to study lattice QCD at finite temperature and chemical potential. We compare it with direct results and with the Glasgow method by using n_f=4 QCD at Im(μ)\neq 0. We locate the critical endpoint (E) of QCD on the Re(μ)-T plane. In this study we use n_f=2+1 dynamical staggered quarks with semi-realistic masses on L_t=4 lattices.

A. Di Giacomo

Investigations on the structure of QCD vacuum from first principles can be done on the lattice. The mechanism of confinement is an example: results from lattice on it are reviewed.

Karl Jansen

In this contribution the costs of simulations employing domain wall and overlap fermions are estimated. In the discussion we will stay within the quenched approximation.

John A. L. McIntosh, Lloyd C. L. Hollenberg

The scaling slope of the anti-symmetric mass gap M of compact U(1)_{2+1} lattice gauge theory is obtained analytically in the Hamiltonian formalism using the plaquette expansion. Based on the first four moments of the Hamiltonian with respect to a one-plaquette mean field state the results demonstrate clear scaling of M at and beyond the transition from stro

James Weatherall

The BABAR detector, at the PEP-II asymmetric B Factory at SLAC collected a sample of 32 million BBbar pairs whilst operating at energies near the Upsilon(4S) resonance between October 1999 and May 2001. An study of time-dependent CP-violating asymmetries in events where one neutral B meson is fully reconstructed in a final state containing charmonium produce

L. Brocco, D. Casadei, F. Cindolo, A. Contin

The Time-of-Flight (TOF) system of the AMS detector gives the fast trigger to the read out electronics and measures velocity, direction and charge of the crossing particles. The new version of the detector (called AMS-02) will be installed on the International Space Station on March 2004. The fringing field of the AMS-02 superconducting magnet is $1.0\div2.5

J. L. A. Coelho, R. L. P. G. Amaral

The Schrödinger equations for the Coulomb and the Harmonic oscillator potentials are solved in the cosmic-string conical space-time. The spherical harmonics with angular deficit are introduced. The algebraic construction of the harmonic oscillator eigenfunctions is performed through the introduction of non-local ladder operators. By exploiting the hidden sym

Jozef Sima, Miroslav Sukenik

The model of Expansive Nondecelerative Universe leads to a conclusion stating that at the end of radiation era the Jeans mass was equal to the upper mass limit of a black hole and, at the same time, the effective gravitational range of nucleons was identical to their Compton wavelength. At that time nucleons started to exert gravitational impact on their env

L. Herrera, D. Pavon

We illustrate and emphasize the relevance of hyperbolic theories of dissipation in different physical scenarios. Particular attention is paid to self-gravitating systems where the relaxation time may become large enough as to require a description of the transient regime. It is argued that even outside that regime, hyperbolic theories may be needed to provid

Matt Visser, Carlos Barcelo, Stefano Liberati

Condensed matter systems, such as acoustics in flowing fluids, light in moving dielectrics, or quasiparticles in a moving superfluid, can be used to mimic aspects of general relativity. More precisely these systems (and others) provide experimentally accessible models of curved-space quantum field theory. As such they mimic kinematic aspects of general relat

Serge Winitzki

The usual scenario of ``eternal inflation'' involves an approximately de Sitter spacetime undergoing upward fluctuations of the local expansion rate $H$. This spacetime requires frequent violations of the Null Energy Condition (NEC). We investigate the fluctuations of the energy-momentum tensor of the scalar field in de Sitter space as a possible sou

Anand Venkataraman

A statistical model for segmentation and word discovery in continuous speech is presented. An incremental unsupervised learning algorithm to infer word boundaries based on this model is described. Results of empirical tests showing that the algorithm is competitive with other models that have been used for similar tasks are also presented.

Anand Venkataraman

We describe an incremental unsupervised procedure to learn words from transcribed continuous speech. The algorithm is based on a conservative and traditional statistical model, and results of empirical tests show that it is competitive with other algorithms that have been proposed recently for this task.

W. Chen

A few novel radial basis function (RBF) discretization schemes for partial differential equations are developed in this study. For boundary-type methods, we derive the indirect and direct symmetric boundary knot methods. Based on the multiple reciprocity principle, the boundary particle method is introduced for general inhomogeneous problems without using in

Martin Cooper, Thomas Schiex

The notion of arc consistency plays a central role in constraint satisfaction. It is known that the notion of local consistency can be extended to constraint optimisation problems defined by soft constraint frameworks based on an idempotent cost combination operator. This excludes non idempotent operators such as + which define problems which are very import

E. A. Goremychkin, R. Osborn, B. D. Rainford, T. A. Costi

By combining the results of muon spin rotation and inelastic neutron scattering in the heavy fermion compounds Ce1-xLaxAl3 (0.0 <= x <= 0.2), we show that static magnetic correlations are suppressed above a characteristic temperature, T*, by electronic dissipation rather than by thermal disorder. Below T*, an energy gap opens in the single-ion magnetic respo

Gabriel A. Cwilich, Fredy R. Zypman

We obtain the statistics of the intensity, transmission and conductance for scalar electromagnetic waves propagating through a disordered collection of scatterers. Our results show that the probability distribution for these quantities, x, follow a universal form x^a Exp(-x^m) . This family of functions includes the Rayleigh distribution (when a=0, m=1) and

G. V. Astakhov, D. R. Yakovlev, V. P. Kochereshko, W. Ossau

Excitons and charged excitons (trions) are investigated in ZnSe-based quantum well structures with (Zn,Be,Mg)Se and (Zn,Mg)(S,Se) barriers by means of magneto-optical spectroscopy. Binding energies of negatively () and positively (X+) charged excitons are measured as functions of quantum well width, free carrier density and in external magnetic fields up to

G. V. Astakhov, V. P. Kochereshko, D. R. Yakovlev, W. Ossau

An optical method is suggested to determine the concentration of two-dimensional electrons in modulation-doped quantum wells at low and moderate electron densities between 10^{9} and 2x10^{11} cm^{-2}. The method is based on an analysis of magneto-reflectivity spectra of charged excitons (trions). The circular polarization degree and the oscillator strength

H. Rosner, A. Kitaigorodsky, W. E. Pickett

The layered lithium borocarbide LiBC, isovalent with and structurally similar to the superconductor MgB2, is an insulator due to the modulation within the hexagonal layers (BC vs. B2). We show that hole-doping of LiBC results in Fermi surfaces of B-C p sigma character that couple very strongly to B-C bond stretching modes, precisely the features that lead to

T. Nagasima, Y. Sugita, A. Mitsutake, Y. Okamoto

In complex systems such as spin systems and protein systems, conventional simulations in the canonical ensemble will get trapped in states of energy local minima. We employ the generalized-ensemble algorithms in order to overcome this multiple-minima problem. Three well-known generalized-ensemble algorithms, namely, multicanonical algorithm, simulated temper

Valeri Kotov, Peter Hirschfeld

We present some preliminary results on the phase diagram of the 2D S=1/2 Kondo lattice model at finite doping. As a starting point the Hamiltonian is written in terms of local spin and charge excitations, and the interactions between these modes are subsequently treated in various perturbative schemes. We find that a paramagnetic-magnetic quantum phase trans

A. Gümbel, J. Eckert, G. Fuchs, K. Nenkov

Highly dense nanocrystalline MgB_2 bulk superconductors with distinctly improved pinning were prepared by mechanical alloying of Mg and B powders and hot compaction at ambient temperatures. The nanocrystalline samples reveal high critical current densities of 105 A/cm2 at 20 K and 1 T together with a strongly shifted irreversibility line towards higher field

I. A. Sergienko

I present here theory of PZT thin film - MgO substrate system thermal expansion effect. I show that elastic properties of the substrate have to be taken into account to describe this effect.

Indubala I. Satija

Disordered systems exhibiting exponential localization are mapped to anisotropic spin chains with localization length being related to the anisotropy of the spin model. This relates localization phenomenon in fermions to the rotational symmetry breaking in the critical spin chains. One of the intriguing consequence is that the statement of Onsager universali

Paul Fendley

Interesting physical results can be obtained from sigma models by taking the number of fields N to zero. I discuss how one can make sense of this limit by using exact S matrix techniques. I review how this can be done for the case of self-avoiding polymers, and speculate on the application to the replica limit of disordered systems.

H. -J. Schmidt, J. Schnack, Marshall Luban

O. Waldmann has shown that some spin systems, which fulfill the condition of a weakly homogeneous coupling matrix, have a spectrum whose minimal or maximal energies are rather poorly approximated by a quadratic dependence on the total spin quantum number. We comment on this observation and provide the new argument that, under certain conditions, the approxim

R. Dolata, H. Scherer, A. B. Zorin, J. Niemeyer

Deep submicron Al-AlOx-Nb tunnel junctions and single electron transistors with niobium islands were fabricated by electron beam gun shadow evaporation. Using stencil masks consisting of the thermostable polymer polyethersulfone (PES) and germanium, high quality niobium patterns with good superconducting properties and a gap energy of up to 2Delta = 2.5 meV

Hari M. Gupta, Jose R. Campanha

Gradually Truncated Log-normal distribution - Size distribution of firms Abstract Many natural and economical phenomena are described through power law or log- normal distributions. In these cases, probability decreases very slowly with step size compared to normal distribution. Thus it is essential to cut-off these distributions for larger step size. Recent

Kazumasa Miyake, Hideaki Maebashi

On the basis of the Ward-Pitaevskii identity, the residual resistivity $ρ_{0}$ is shown to exhibit huge enhancement around the quantum critical point of valence transition in Ce-based heavy electron systems. This explains a sharp peak of $ρ_{0}$ observed in CeCu$_2$Ge$_2$ under the pressure at $P\sim$16GPa where the superconducting trasition temperature also

F. Triozon, J. Vidal, R. Mosseri, D. Mayou

We investigate the properties of electronic states in two and three-dimensional quasiperiodic structures: the generalized Rauzy tilings. Exact diagonalizations, limited to clusters with a few thousands sites, suggest that eigenstates are critical and more extended at the band edges than at the band center. These trends are clearly confirmed when we compute t

J. Fransson, O. Eriksson, I. Sandlov

A theoretical technique which allows to include contributions from non-orthogonality of the electron states in the leads connected to a tunneling junction is derived. The theory is applied to a single barrier tunneling structure and a simple expression for the time-dependent tunneling current is derived showing explicit dependence of the overlap. The overlap

J. Fransson, O. Eriksson, B. Johansson, I. Sandalov

An approach which allows to include the corrections from non-orthogonality of electron states in contacts and quantum dots is developed. Comparison of the energy levels and charge distributions of electrons in 1D quantum dot (QD) in equilibrium, obtained within orthogonal (OR) and non-orthogonal representations (NOR), with the exact ones shows that the NOR p

G. L. Salmond, C. A. Holmes, G. J. Milburn

We consider a two component Bose-Einstein condensate in two spatially localized modes of a double well potential, with periodic modulation of the tunnel coupling between the two modes. We treat the driven quantum field using a two mode expansion and define the quantum dynamics in terms of the Floquet Operator for the time periodic Hamiltonian of the system.

S. Banerjee, S. Kundu

We have presented the kinetic study of the very initial growth stages of an ultra thin film (40 $Å$- 150$Å$) of Ag sputter-deposited on Si(001) substrate containing native oxide using grazing incidence x-ray reflectivity (GIXR) technique and Atomic Force Microscopy (AFM). We observe that the film consists of mounds with the presence of voids. The thickness `

A. Yu. Cherny, A. A. Shanenko

The kinetic and interaction energies of a three-dimensional dilute ground-state Bose gas confined in a trap are calculated beyond a mean-field treatment. They are found to depend on the pairwise interaction trough two characteristic lengths: the first, a, is the well-known scattering length and the second, b, is related to the latter by b=a-λd a/dλwith λbein

Thomas G. Pannuti, Glenn E. Allen

G347.3-0.5 (RX J1713.7-3946) is a member of the new class of shell-type Galactic supernova remnants (SNRs) that feature non-thermal components to their X-ray emission. We have analyzed the X-ray spectrum of this SNR over a broad energy range (0.5 to 30 keV) using archived data from observations made with two satellites, the Roentgenstaellit (ROSAT) and the A

B. M. Gaensler, J. Arons, M. J. Pivovaroff, V. M. Kaspi

The young and energetic pulsar B1509-58 powers a bright X-ray synchrotron nebula, embedded in the unusual supernova remnant G320.4-1.2. We present observations of this system with the Chandra X-ray Observatory, which show a spectacularly complicated source. The nebula is dominated by a bright collimated feature which we interpret as a relativistic jet direct

F. E. Bauer, D. M. Alexander, W. N. Brandt, A. E. Hornschemeier

The ~1 Ms Chandra Deep Field North observation is used to study the extended X-ray sources in the region surrounding the Hubble Deep Field North (HDF-N), yielding the most sensitive probe of extended X-ray emission at cosmological distances to date. A total of six such sources are detected, the majority of which align with small numbers of optically bright g

Philip J. Armitage, Ian A. Bonnell

We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming at the same time as the primary star have masses which are comparable to the initial mass of the protoplanetary disc. S

Nectaria A. B. Gizani, M. A. Garrett, J. P. Leahy

We present the kpc-scale behaviour of the powerful extragalactic radio source Hercules A and the behaviour of the intracluster gas in which the radio source is situated. We have found that Hercules A exhibits a strong Laing-Garrington effect. The X-ray observations have revealed an extended X-ray emission elongated along the radio galaxy axis. The estimated

A. N. Taylor

I show how weak gravitational lensing can be used to image the 3-D mass distribution in the Universe. An inverse relation to the lensing equation, relating the lensing potential evaluated at each source to the full 3-D Newtonian potential, is derived. I consider the normal modes of the lensing problem and clarify the equations using a small-angle approximati

A. V. Thampan

Structure parameters of rapidly rotating strange stars are compared with those for neutron stars. The salient differences are pointed out.

Peter Todd Williams

Jets are ubiquitous in astronomy. It has been conjectured that the existence of jets is intimately connected with the spin of the central object and the viscous angular momentum transport of the inner disk. Bipolar jet-like structures propelled by the viscous torque on a spinning central object are also known in a completely different context, namely the flo

M. Odenkirchen, C. Soubiran

The sparse stellar ensemble NGC 6994 = M73 has recently been discussed as a possible remnant of an old open cluster. In order to solve the controversy on the nature of this object we have taken high-resolution spectra of the six brightest stars within 6&#39; angular distance of its nominal position. These stars are the only obvious member candidates for an e

M. Lecar, F. Franklin, M. Holman, N. Murray

The physical basis of chaos in the solar system is now better understood: in all cases investigated so far, chaotic orbits result from overlapping resonances. Perhaps the clearest examples are found in the asteroid belt. Overlapping resonances account for its Kirkwood gaps and were used to predict and find evidence for very narrow gaps in the outer belt. Fur

J. M. De Buizer, A. Watson, J. T. Radomski, R. K. Pina

We present high angular resolution (~0.5&#34;) 10 and 18 micron images of the region around G29.96-0.02 taken from the Gemini North 8-m telescope using the mid-infrared imager and spectrometer OSCIR. These observations were centered on the location of a group of water masers, which delineate the site of a hot molecular core believed to contain an extremely y

Lawrence M. Krauss, Brian Chaboyer

New estimates of globular cluster distances, combined with revised ranges for input parameters in stellar evolution codes and recent estimates of the earliest redshift of cluster formation allow us to derive a new 95% confidence level lower limit on the age of the Universe of 11 Gyr. This is now definitively inconsistent with the expansion age for a flat Uni

F. Mavromatakis, P. Boumis, E. V. Paleologou

We present the first CCD mosaic ever produced for the supernova remnant G 65.3+5.7 in [OII] 3727 at a moderate angular resolution. The remnant was observed with the 0.3 m wide-field telescope at Skinakas Observatory, Crete, Greece. Low resolution spectroscopy was performed at selected areas around this extended remnant. The spectral data are under analysis,

Charles R. Keeton

Substructure in distant gravitational lens galaxies can be detected because it alters the brightnesses and shapes of the lensed images. The optical and radio flux ratios in the four-image lens B1422+231 imply that there is a \sim 10^4-10^7 Msun/h mass clump in the lens galaxy in front of image A; this is the first constraint on the mass of a particular clump

F. Mavromatakis, P. Boumis, E. V. Paleologou

We present results from a first analysis of optical data on G 69.4+2.4 obtained with the 0.3 m and 1.3 m telescopes at Skinakas Observatory. Filamentary emission is detected in the [OIII] 5007 A and Halpha+[NII] images oriented in the south-west, north-east direction. The Halpha+[NII] images reveal a complex network of filaments, while the [OIII] images show

Paolo Molaro

Neutral hydrogen clouds with high column density detected towards distant quasars are unique probes of elemental nucleosynthesis and chemical evolution in the low metallicity regime. They provide measurements for several elements at very early times which are unfeasible in other astrophysical environments. Comparison between refractory and non-refractory ele

A. Aragon-Salamanca, B. Milvang-Jensen, G. Hau, I. Jorgensen

We are carrying out a programme to measure the evolution of the stellar and dynamical masses and M/L ratios for a sizeable sample of morphologically-classified disk galaxies in rich galaxy clusters at 0.2<z<0.9. Using FORS2 at the VLT we are obtaining rotation curves for the cluster spirals so that their Tully-Fisher relation can be studied as a function of

P. Molaro, S. A. Levshakov, M. Dessauges-Zavadsky, S. D&#39;Odorico

From the analysis of the CII fine-structure population ratio in the damped Ly_alpha system at z = 3.025 toward the quasar Q0347--3819 we derive an upper bound of 14.6 (+/- 0.2) K on the cosmic microwave background temperature regardless the presence of other different excitation mechanisms. The analysis of the ground state rotational level populations of H_2

Pierre-Alain Duc, Jonathan Braine, Ute Lisenfeld, Philippe Amram

As a result of internal processes or environmental effects like ram-pressure stripping or collisions, galaxies lose a significant part of their stellar and gaseous content. Whereas the impact of such stripping on galaxy evolution has been well studied, much less attention has been given to the fate of the expelled material in the intergalactic or intracluste

David Blaschke, Sverker Fredriksson, Ahmet Mecit Oztas

We present various results from including diquark properties and the gap equations into the TOV equations for compact quark objects. One such property is the diquark form factor, which has a strong influence on various quantities. We discuss the consequences for quark stars.

S. Ettori, A. C. Fabian, S. W. Allen, R. M. Johnstone

We present X-ray spatial and spectral analysis of the Chandra data from the central 400 kpc (H0 = 50 km/s/Mpc) of the cluster of galaxies Abell 1795. The plasma temperature rises outwards by a factor of 3, whereas the iron abundance decreases by a factor of 4. The spatial distribution of Oxygen, Neon, Sulphur, Silicon and Iron shows that supernovae Type Ia d

M. Kutschera, S. Stachniewicz, A. Szmaglinski, W. Wojcik

We study properties of the proton component of neutron star matter for a number of realistic nuclear models. Protons which form a few percent admixture tend to be localized in potential wells corresponding to neutron matter inhomogeneities created by the protons in the neutron medium. We calculate the energy of the Wigner-Seitz cell enclosing a single locali

G. Ghisellini

Gamma Ray Bursts (GRBs) are the most explosive events after the big bang: their energy output corresponds to a sizeable fraction of a solar mass entirely converted into energy in a few seconds. Although many questions about their progenitors remain to be answered, it is likely that they are generated by a newly formed and fast spinning black hole. The coloss

Patrick A. Woudt, Brian Warner

We have found a 2.09 h modulation in brightness of the dwarf nova GW Lib. This bears no special relationship to the 1.28 h spectroscopic period that is believed to be the orbital period. It was present in May 2001, but not in observations made in 1997 and 1998 and is of unknown origin. Similar unexplained periodicities are present in FS Aur and V2051 Oph.

N. Andersson, D. I. Jones, K. D. Kokkotas

We investigate the relevance of the gravitational-wave driven r-mode instability for strange stars. We find that the unstable r-modes affect strange stars in a way that is quite distinct from the neutron star case. For accreting strange stars we show that the onset of r-mode instability does not lead to the thermo-gravitational runaway that is likely to occu

S. Arbabi-Bidgoli, V. Mueller

An analysis of voids using cosmological N-body simulations of cold dark matter models is presented. It employs a robust statistics of voids, that was recently applied to discriminate between data from the Las Campanas Redshift Survey and different cosmological models. Here we extend the analysis to 3D and show that typical void sizes D in the simulated galax

Rino Bandiera

High-quality spatially resolved spectra of synchrotron emission from plerions represent a powerful diagnostic tool for the physical conditions in these objects. A fundamental question is to what extent spatial variations of the synchrotron spectrum originate from the evolution of a single population of injected electrons, and when instead they imply the coex

Manuel Perucho, Jose Maria Marti

We present a model to determine the physical parameters of jets and hot spots of a sample of CSOs under very basic assumptions like synchrotron emission and minimum energy conditions. Based on this model we propose a simple evolutionary scenario for these sources assuming that they evolve in ram pressure equilibrium with the external medium and constant jet

S. Safi-Harb, I. M. Harrus, R. Petre, G. G. Pavlov

G21.5-0.9 is a plerionic supernova remnant (SNR) whose properties hint at the presence of a pulsar -- yet no pulsations have been found at any wavelength. Early observations with Chandra led to the discovery of an extended component, making the SNR at least twice as big as originally thought. Our analysis indicates that this low-surface brightness extended c

J. P. Halpern, E. V. Gotthelf, F. Camilo, B. Collins

With a period of 51.6 ms and spin-down power 2.2x10^{37} erg s^{-1}, PSR J2229+6114 is a compelling identification for the EGRET source 3EG J2227+6122 in which error circle it resides. Striking features of the Chandra X-ray image are an incomplete elliptical arc and a possible jet, similar to the structures that dominate the appearance of the Vela PWN. Appro

Mohsen Shadmehri, Enrique Vazquez-Semadeni, Javier Ballesteros-Paredes

We discuss the virial balance of all members of a cloud ensemble in numerical simulations of self-gravitating MHD turbulence. We first discuss the choice of reference frame for evaluating the terms entering the virial theorem (VT), concluding that the balance of each cloud should be measured in its own reference frame. We then report preliminary results sugg

David Branch, E. Baron, David J. Jeffery

Supernova flux and polarization spectra bring vital information on the geometry, physical conditions, and composition structure of the ejected matter. For some supernovae the circumstellar matter is also probed by the observed spectra. Some of this information can be inferred directly from the observed line profiles and fluxes, but because of the Doppler bro

R. Haslinger, Ar. Abanov, A. Chubukov

We address the issue whether ARPES measurements of the spectral function $A_k (ω)$ near the Fermi surface in the normal state of near optimally doped cuprates can distinguish between the marginal Fermi liquid scenario and the spin-fluctuation scenario. We argue that the data for momenta near the Fermi surface are equally well described by both theories, but

M. B. Halpern, Charles B. Thorn

We report a simplification in the large N matrix mechanics of light-cone matrix field theories. The absence of pure creation or pure annihilation terms in the Hamiltonian formulation of these theories allows us to find their reduced large N Hamiltonians as explicit functions of the generators of the Cuntz algebra. This opens up a free-algebraic playground of

Solange V. Ramirez, Judith G. Cohen

We present abundance ratios for 23 elements with respect to Fe in a sample of stars with a wide range in luminosity, from luminous giants to stars near the turnoff, in the globular cluster M71. The analyzed spectra, obtained with HIRES at the Keck Observatory, are of high dispersion (R=35,000). We find that the neutron capture, the iron peak and the alpha-el

Sharon M. Morsink, Vahid Rezania

We investigate the effect of a magnetic field on the global oscillation modes of a rotating fluid star in the magnetohydrodynamic approximation. We present general equations for the modification of any type of fluid mode due to a general magnetic field which is not aligned with the star&#39;s spin axis. In the case of any internal dipole magnetic field we de

Axel Brandenburg, Dmitry Sokoloff

Various approaches to estimate turbulent transport coefficients from numerical simulations of hydromagnetic turbulence are discussed. A quantitative comparison between the averaged magnetic field obtained from a specific three-dimensional simulation of a rotating turbulent shear flow in a slab and a simple one-dimensional alpha-omega dynamo model is given. A

Malcolm Fairbairn, Louise M Griffiths

We consider the production of gravitational KK modes via cosmological photon-photon and electron-positron annihilation in models with large factorisable extra dimensions. We place constraints on this production using recent results from a joint analysis of the power spectra of the 2dF Galaxy Redshift Survey (2dFGS) and the cosmic microwave background (CMB) a

Gia Dvali, Gregory Gabadadze, Xin-rui Hou, Emiliano Sefusatti

We discuss a model in which the fundamental scale of gravity is restricted to 10^{-3} eV. An observable modification of gravity occurs simultaneously at the Hubble distance and at around 0.1 mm. These predictions can be tested both by the table-top experiments and by cosmological measurements. The model is formulated as a brane-world theory embedded in a spa

Pei Ming Ho, Sanjaye Ramgoolam

Matrix descriptions of even dimensional fuzzy spherical branes $S^{2k} $ in Matrix Theory and other contexts in Type II superstring theory reveal, in the large $N$ limit, higher dimensional geometries $SO(2k+1)/U(k)$, which have an interesting spectrum of $SO(2k+1)$ harmonics and can be up to 20 dimensional, while the spheres are restricted to be of dimensio

A. Brandenburg, W. Dobler, K. Subramanian

The theory of large scale dynamos is reviewed with particular emphasis on the magnetic helicity constraint in the presence of closed and open boundaries. In the presence of closed or periodic boundaries, helical dynamos respond to the helicity constraint by developing small scale separation in the kinematic regime, and by showing long time scales in the nonl

T. Korhonen, B. Kalantari

In the initial phase of the Swiss Light Source, four insertion devices will be installed. The control system for all the ID&#39;s follows an uniform concept to allow a rapid installation schedule, while at the same time allowing for a variety in operational requirements. The components of the control system include the gap drive system with encoders, tempera

J. Christopher Howk, Kenneth R. Sembach, Blair D. Savage, Derck Massa

We present FUSE observations of interstellar O VI absorption towards 12 early-type stars in the Large Magellanic Cloud (LMC). O VI 1031.926 Ang absorption at LMC velocities is seen towards all 12 stars. The observed columns are in the range log N(O VI)=13.9 to 14.6, with a mean of 14.37. The observations probe several sight lines projected onto known superbu

H. George E. Hentschel, Anders Levermann, Itamar Procaccia

We study the fractal and multifractal properties (i.e. the generalized dimensions of the harmonic measure) of a 2-parameter family of growth patterns that result from a growth model that interpolates between Diffusion Limited Aggregation (DLA) and Laplacian Growth Patterns in 2-dimensions. The two parameters are βwhich determines the size of particles accret

P. Aliani, V. Antonelli, M. Picariello, E. Torrente-Lujan

An updated analysis of all available neutrino oscillation evidence in Solar experiments including the latest $SNO$ data is presented. Predictions for total rates and day-night asymmetry in Borexino are calculated. Our analysis features the use of exhaustive computation of the neutrino oscillation probabilities and the use of an improved statistical $χ^2$ min

Vladimir Sauli, Jiri Adam

The Bethe-Salpeter equation for Wick-Cutkosky like models is solved in dressed ladder approximation. The bare vertex truncation of the Dyson-Schwinger equations for propagators is combined with the dressed ladder Bethe-Salpeter equation for the scalar S-wave bound state amplitudes. With the help of spectral representation the results are obtained directly in

Fabio Taddei, Rosario Fazio

Due to the Fermionic nature of carriers, correlations between electric currents flowing through two different contacts attached to a conductor present a negative sign. Possibility for positive cross-correlations has been demonstrated in hybrid normal/superconductor structures under certain conditions. In this paper we show that positive cross-correlations ca

Jaume Garriga, Oriol Pujolas, Takahiro Tanaka

We consider a class of 5-D brane-world solutions with a power-law warp factor $a(y)\propto y^{q}$, and bulk dilaton with profile $ϕ\propto \ln y$, where $y$ is the proper distance in the extra dimension. This class includes the Heterotic M-theory brane-world of Refs. \cite{ovrut,ekpy} and the Randall-Sundrum (RS) model as a limiting case. In general, there a

M. C. Gonzalez-Garcia, C. Peña-Garay

If the solution to the solar neutrino puzzle falls in the LMA region, KamLAND should be able to measure with good precision the corresponding oscillation parameters after a few years of data taking. Assuming a positive signal, we study their expected sensitivity to the solar parameters (theta_{12},Delta m^2_{21}) when considered in the framework of three-neu

H. J. de Vega, J. A. Siebert

We study the statistical mechanics of the self-gravitating gas at thermal equilibrium with two kinds of particles. We start from the partition function in the canonical ensemble which we express as a functional integral over the densities of the two kinds of particles for a large number of particles. The system is shown to possess an infinite volume limit wh

J. P. Ma, J. S. Xu

We study diffractive photoproduction of $J/ψ$ by taking the charm quark as a heavy quark. A description of nonperturbative effect related to $J/ψ$ can be made by using NRQCD. In the forward region of the kinematics, the interaction between the $c\bar c$-pair and the initial hadron is due to exchange of soft gluons. The effect of the exchange can be studied b

V. Naidenko, Yu. Orlovich

For a given finite class of finite graphs H, a graph G is called a realization of H if the neighbourhood of its any vertex induces the subgraph isomorphic to a graph of H. We consider the following problem known as the Generalized Neighbourhood Problem (GNP): given a finite class of finite graphs H, does there exist a non-empty graph G that is a realization

Chris J. Willott, Steve Rawlings, Elese N. Archibald, James S. Dunlop

We present submillimetre photometry of 11 3CR and 6CE radio quasars of similar 151-MHz radio luminosity and redshifts to the radio galaxies studied at 1.3<z<2 by Archibald et al. (2001). We detect all bar one quasar at 850 microns, and five quasars are confirmed as dusty hyperluminous objects by detections at shorter wavelengths. Our observations reveal a cl

A. Bilal, J. -P. Derendinger, K. Sfetsos

The aim of this paper is two-fold. First, we provide a simple and pedagogical discussion of how compactifications of M-theory or supergravity preserving some four-dimensional supersymmetry naturally lead to reduced holonomy or its generalization, reduced weak holonomy. We relate the existence of a (conformal) Killing spinor to the existence of certain closed

G. Hackenbroich, C. Viviescas, F. Haake

Feshbach&#39;s projector technique is employed to quantize the electromagnetic field in optical resonators with an arbitray number of escape channels. We find spectrally overlapping resonator modes coupled due to the damping and noise inflicted by the external radiation field. For wave chaotic resonators the mode dynamics is determined by a non--Hermitean ra

B. N. Kalinkin, F. A. Gareev

The connection of synthesis of long-lived superheavy nuclei and existence of the island of stability with the choice of realistic nuclear potential is discussed: the behaviour of the average field of nuclei is an important element of nuclear models. It is also shown that it is just Dubna that possesses the priority both in the recent synthesis of a superheav

Arun K. Pati

We prove a general limitation in quantum information that unifies the impossibility principles such as no-cloning and no-anticloning. Further, we show that for an unknown qubit one cannot design a universal Hadamard gate for creating equal superposition of the original and its complement state. Surprisingly, we find that Hadamard transformations exist for an

J. A. Pons, E. Berti, L. Gualtieri, G. Miniutti

The effects that the structure of a neutron star would have on the gravitational emission of a binary system are studied in a perturbative regime, and in the frequency domain. Assuming that a neutron star is perturbed by a point mass moving on a close, circular orbit, we solve the equations of stellar perturbations in general relativity to evaluate the energ

A Donnachie, P V Landshoff

We explain how Regge theory and perturbative evolution may be made compatible at small x. The result not only gives striking support to the two-pomeron description of small-x behaviour, but gives a rather clean test of perturbative QCD itself. When x is very small, or Q^2 is very large, the proton&#39;s gluon distribution function is significantly larger tha

Anita Mehta, R. A. Cowley

A theoretical framework is developed to describe experiments on the structure of epitaxial thin films, particularly niobium on sapphire. We extend the hypothesis of dynamical scaling to apply to the structure of thin films from its conventional application to simple surfaces. We then present a phenomenological continuum theory that provides a good descriptio

O. F. Dayi, A. Jellal

We consider electrons in uniform external magnetic and electric fields which move on a plane whose coordinates are noncommuting. Spectrum and eigenfunctions of the related Hamiltonian are obtained. We derive the electric current whose expectation value gives the Hall effect in terms of an effective magnetic field. We present a receipt to find the action whic