September 2002 arXiv papers — page 10

O. Radulescu, P. D. Olmsted, J. P. Decruppe, S. Lerouge

We show the existence of three well defined time scales in the dynamics of wormlike micelles after a step between two shear rates on the stress plateau. These time scales are compatible with the presence of a structured interface between bands of different viscosities and correspond to the isotropic band destabilization during the stress overshoot, reconstru

N. A. Babushkina, E. A. Chistotina, O. Yu. Gorbenko, A. R. Kaul

The effect of $^{16}$O $\to$ $^{18}$O isotope substitution on electrical resistivity and magnetic susceptibility of Sm$_{1-x}$Sr$_x$MnO$_3$ manganites is analyzed. It is shown that the oxygen isotope substitution drastically affects the phase diagram at the crossover region between the ferromagnetic metal state and that of antiferromagnetic insulator (0.4 $<

D. Fournier, M. Poirier, M. Castonguay, K. Truong

The phase diagram of the organic superconductor $κ$-(BEDT-TTF)$_2$Cu[N(CN)$_2$Cl has been investigated by ultrasonic velocity measurements under helium gas pressure. Different phase transitions were identified trough several elastic anomalies characterized from isobaric and isothermal sweeps. Our data reveal two crossover lines that end on the critical point

Jijun Zhao, Buia Calin, Jie Han, Jian Ping Lu

The quantum transport properties of the ultrathin silver nanowires are investigated. For a perfect crystalline nanowire with four atoms per unit cell, three conduction channels are found, corresponding to three $s$ bands crossing the Fermi level. One conductance channel is disrupted by a single-atom defect, either adding or removing one atom. Quantum interfe

Luis A. Pugnaloni, Ileana F. Marquez, Fernando Vericat

During the last few years, a number of works in computer simulation have focused on the clustering and percolation properties of simple fluids based in an energetic connectivity criterion proposed long ago by T.L. Hill [J. Chem. Phys. 23, 617 (1955)]. This connectivity criterion appears to be the most appropriate in the study of gas-liquid phase transition.

Jun Goryo, Mahito Kohmoto

We comment on the relation between Berry phase and quantized Hall conductivities for charge and spin currents in some Bloch states, such as Bloch electrons in the presence of electromagnetic fields and quasiparticles in the vortex states of superfluid $^3$He. One can find out that the arguments presented here are closely related to the spontaneous polarizati

S. G. Srinivasan, D. M. Hatch, H. T. Stokes, A. Saxena

Many structural transformations involve a group-nonsubgroup relationship between the initial and transformed phases, and hence are beyond the purview of conventional Landau theory. We utilize a systematic and robust methodology to describe such reconstructive martensitic transformations by coupling group-theoretical arguments to first-principles calculations

Kun Yang, You-Quan Li

For a two-component bosonic system, the components can be mapped onto a pseudo-spin degree of freedom with spin quantum number S=1/2. We provide a rigorous proof that for a wide-range of real Hamiltonians with component independent mass and interaction, the ground state is a ferromagnetic state with pseudospin fully polarized. The spin-wave excitations are s

D. Costa, G. Pellicane, M. C. Abramo, C. Caccamo

The free energy of the solid and fluid phases of the Girifalco C60 model are determined through extensive Monte Carlo simulations. In this model the molecules interact through a spherical pair potential, characterized by a narrow and attractive well, adjacent to a harshly repulsive core. We have used the Widom test particle method and a mapping from an Einst

M. Bak, A. Avella, F. Mancini

The relevance of zero-energy functions, coming from zero-energy modes and present in the structure of bosonic Green&#39;s functions, is often underestimated. Usually, their values are fixed by assuming the ergodicity of the dynamics, but it can be shown that this is not always correct. As the zero-energy functions are connected to fundamental response proper

Sanjay Puri, Kay Joerg Wiese

We develop perturbative expansions to obtain solutions for the initial-value problems of two important reaction-diffusion systems, viz., the Fisher equation and the time-dependent Ginzburg-Landau (TDGL) equation. The starting point of our expansion is the corresponding singular-perturbation solution. This approach transforms the solution of nonlinear reactio

G. Kiesslich, A. Wacker, E. Schoell, A. Nauen

The shot noise suppression in a sample containing a layer of self-assembled InAs quantum dots has been investigated experimentally and theoretically. The observation of a non-monotonic dependence of the Fano factor on the bias voltage in a regime where only few quantum dot ground states contribute to the tunneling current is analyzed by a master equation mod

Daniel Faller, Francesco Petruccione

A master equation approach to the numerical solution of option pricing models is developed. The basic idea of the approach is to consider the Black--Scholes equation as the macroscopic equation of an underlying mesoscopic stochastic option price variable. The dynamics of the latter is constructed and formulated in terms of a master equation. The numerical ef

Edward McCann, Vladimir I. Fal&#39;ko

We present a theoretical description of the thermopower due to magnon-assisted tunneling in a mesoscopic tunnel junction between two ferromagnetic metals. The thermopower is generated in the course of thermal equilibration between two baths of magnons, mediated by electrons. For a junction between two ferromagnets with antiparallel polarizations, the ability

S. Fratini, B. Valenzuela, D. Baeriswyl

We study a system of electrons on a one-dimensional lattice, interacting through the long range Coulomb forces, by means of a variational technique which is the strong coupling analog of the Gutzwiller approach. The problem is thus the quantum version of Hubbard&#39;s classical model of the generalized Wigner crystal [J. Hubbard, Phys. Rev. B 17, 494 (1978)]

T. Martin, A. Crepieux, N. Chtchelkatchev

The aim of this chapter is to describe two situations where positive noise correlations can be directly monitored using a transport experiment, either with a superconductor or with a correlated electron system. To be more precise, the present text reflects the presentations made by the three authors during the Delft NATO workshop. Bell inequalities and quant

D. Daghero, R. S. Gonnelli, G. A. Ummarino, V. A. Stepanov

We present the results of a spectroscopic study of state-of-the-art MgB2 single crystals, carried out by using a modified point-contact technique. The use of single crystals allowed us to obtain point contacts with current injection either parallel or perpendicular to the ab planes. The effect of magnetic fields up to 9 T on the conductance spectra of these

Roser Valenti, T. Saha-Dasgupta, F. Mila

Motivated by an early experimental study of VOSeO3, which suggested that it is a quasi-2D system of weakly coupled spin dimers with a small spin gap, we have investigated the electronic structure of this material via density-functional calculations. These ab initio results indicate that the system is better thought of as an alternating spin-1/2 chain with mo

Alfio Borzi, Georg Stadler, Ulrich Hohenester

Coherent carrier control in quantum nanostructures is studied within the framework of Optimal Control. We develop a general solution scheme for the optimization of an external control (e.g., lasers pulses), which allows to channel the system&#39;s wavefunction between two given states in its most efficient way; physically motivated constraints, such as limit

M. I. Dykman, P. M. Platzman, P. Seddighrad

We study dissipation effects for electrons on the surface of liquid helium, which may serve as qubits of a quantum computer. Each electron is localized in a 3D potential well formed by the image potential in helium and the potential from a submicron electrode submerged into helium. We estimate parameters of the confining potential and characterize the electr

Jorge Kurchan

I briefly review the three nonperturbative methods for the treatment of disordered systems -- supersymmetry, replicas and dynamics -- with a parallel presentation that highlights their connections and differences.

Jonathan P. K. Doye, David J. Wales, Fredrik H. M. Zetterling, Mikhail Dzugutov

We examine the favoured cluster structures for two new potentials, which both behave as monatomic model glass-formers in bulk. We find that the oscillations in the interatomic potential lead to global minima that are non-compact arrangements of linked 13-atom icosahedra. We find that the structural properties of the clusters correlate with the glass-forming

F. Yusef-Zadeh, M. Wardle, D. A. Roberts

The W28 supernova remnant is an excellent prototype for observing shocked gas resulting from the interaction of supernova remnants (SNRs) and adjacent molecular clouds (MCs). We present two new signatures of shocked molecular gas in this remnant. One is the detection of main-line extended OH (1667 MHz) absorption with broad linewidths. The column density of

Jack R. Gabel, D. Michael Crenshaw, Steven B. Kraemer, W. N. Brandt

We present observations of the intrinsic absorption in the Seyfert 1 galaxy NGC 3783 obtained with the STIS/HST and FUSE. We have coadded multiple STIS and FUSE observations to obtain a high S/N averaged spectrum spanning 905-1730 A. The averaged spectrum reveals absorption in O VI, N V, C IV, N III, C III and the Lyman lines up to LyE in the three blueshift

Weiqun Zhang, S. E. Woosley

Growing observational evidence supports the proposition that gamma-ray bursts (GRBs) are powered by relativistic jets from massive helium stars whose cores have collapsed to black holes and an accretion disk (collapsars). We model the propagation of relativistic jets through the stellar progenitor and its wind using a two-dimensional special relativistic hyd

Carmelle Robert, Anne Pellerin, Alessandra Aloisi, Claus Leitherer

We have generated a set of far-ultraviolet stellar libraries using spectra of OB and Wolf-Rayet stars in the Galaxy and the Large and Small Magellanic Cloud. The spectra were collected with the Far Ultraviolet Spectroscopic Explorer and cover a wavelength range from 1003.1 to 1182.7A at a resolution of 0.127A. The libraries extend from the earliest O- to lat

F. Camilo, R. N. Manchester, B. M. Gaensler, D. R. Lorimer

We report the discovery of PSR J1747-2958, a radio pulsar with period P = 98 ms and dispersion measure DM = 101 pc/cc, in a deep observation with the Parkes telescope of the axially-symmetric &#34;Mouse&#34; radio nebula (G359.23-0.82). Timing measurements of the newly discovered pulsar reveal a characteristic age Pdt/2dP = 25 kyr and spin-down luminosity dE

M. R. Blanton, D. W. Hogg, N. A. Bahcall, I. K. Baldry

Using photometry and spectroscopy of 144,609 galaxies from the Sloan Digital Sky Survey, we present bivariate distributions of pairs of seven galaxy properties: four optical colors, surface brightness, radial profile shape as measured by the Sersic index, and absolute magnitude. In addition, we present the dependence of local galaxy density (smoothed on 8 h^

J. Kovac, E. M. Leitch, C. Pryke, J. E. Carlstrom

We report the detection of polarized anisotropy in the Cosmic Microwave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. Observations in all four Stokes parameters were obtained within two 3.4 FWHM fields separated by one hour in Right Ascension. The fields were selected from

J. Wren, K. Borozdin, S. Brumby, D. Casperson

The Rapid Telescope for Optical Response (RAPTOR) program consists of a network of robotic telescopes dedicated to the search for fast optical transients. The pilot project is composed of three observatories separated by approximately 38 kilometers located near Los Alamos, New Mexico. Each of these observatories is composed of a telescope, mount, enclosure,

E. M. Leitch, J. M. Kovac, C. Pryke, B. Reddall

We describe an experiment to measure the polarization of the Cosmic Microwave Background (CMB) with the Degree Angular Scale Interferometer (DASI), a compact microwave interferometer optimized to detect CMB anisotropy at multipoles 140 to 900. The telescope has operated at the Amundsen-Scott South Pole research station since 2000 January. The telescope was r

D. Lutz, R. Maiolino, A. F. M. Moorwood, H. Netzer

The state of the matter that is obscuring a small circumnuclear region in AGN can be probed by observations of its broad emission lines. Infrared lines are particularly useful since they penetrate significant columns of obscuring matter, the properties of which can be constrained by comparing infrared and X-ray obscuration. We report on new 4um spectroscopy

A. Di Paola, V. Larionov, A. Arkharov, F. Bernardi

On the 13th of May 2002, supernova 2002cv was discovered using a near-infrared camera working at the AZT-24 1.1m telescope at Campo Imperatore (AQ-Italy). After the infrared detection a simultaneous photometric follow-up was started at optical wavelengths. The preliminary results confirm a heavily obscured object with a V-K color not lower than 6 magnitudes,

L. Morales-Rueda, P. F. L. Maxted, T. R. Marsh, R. C. North

Subdwarf B (sdB) stars are thought to be core helium burning stars with low mass hydrogen envelopes. In recent years it has become clear that many sdB stars lose their hydrogen through interaction with a binary companion and continue to reside in binary systems today. In this paper we present the results of a programme to measure orbital parameters of binary

Robert F. Stein, Aake Nordlund

Magneto-convection simulations on meso-granule and granule scales near the solar surface are used to study small scale dynamo activity, the emergence and disappearance of magnetic flux tubes, and the formation and evolution of micropores. From weak seed fields, convective motions produce highly intermittent magnetic fields in the intergranular lanes which co

Edwin Sirko, Jeremy Goodman

We calculate spectral energy distributions (SEDs) of steady accretion discs at high accretion rates, as appropriate for bright QSOs, under the assumption that the outer parts are heated sufficiently to maintain marginal gravitational stability, presumably by massive stars formed within the disc. The SED is independent of the nature of these auxiliary sources

M. A. Garrett

There are at least four well known Very Long Baseline Interferometer (VLBI) networks that provide open access to astronomers around the world. These include the EVN, VLBA, CMVA and APT/LBA. In this paper I have chosen to focus on a sub-set of these facilities, in particular the European VLBI Network, both in stand-alone mode but also as a major component of

J. -F. Olive, D. Barret, M. Gierlinski

We follow the timing properties of the neutron star low-mass X-ray binary system 4U 1705-44 in different spectral states, as monitored by the Rossi X-ray Timing Explorer over about a month. We fit the power density spectra using multiple Lorentzians. We show that the characteristic frequencies of these Lorentzians, when properly identified, fit within the co

Jean-Francois Cardoso, Hichem Snoussi, Jacques Delabrouille, Guillaume Patanchon

We present a new source separation method which maximizes the likelihood of a model of noisy mixtures of stationary, possibly Gaussian, independent components. The method has been devised to address the problem of imaging CMB anisotropies. It works in the spectral domain where, thanks to two simple approximations, the likelihood assumes a simple form which i

L. Testi, F. Bacciotti, A. I. Sargent, T. P. Ray

We present high angular resolution millimeter wavelength continuum and 13CO(2-1) observations of the circumstellar disk surrounding the TTauri star DG Tauri. We show that the velocity pattern in the inner regions of the disk is consistent with Keplerian rotation about a central 0.67 Msun star. The disk rotation is also consistent with the toroidal velocity p

Celine Peroux

Although quasar absorbers, and in particular Damped Lyman-alpha systems (DLAs) have proven a valuable tool to study the early Universe, their exact nature is so far poorly constrained. It has been suggested that outflows in galaxies might account for at least part of the DLA population. Observational evidences and models in support of this hypothesis are rev

Jozef Klacka

Relativistically covariant form of equation of motion for arbitrarily shaped dust particle (neutral in charge) under the action of electromagnetic radiation is derived -- emission, scattering and absorption of radiation is considered. The result is presented in the form of optical quantities used in optics of dust particles. The obtained equation of motion r

Lifang Xia, Xu Zhou, Jun Ma, Hong Wu

In this paper, we present the methodology of photometric redshift determination with the BATC 15-color system by using hyperz program. Both simulated galaxies and real galaxies with known redshifts were used to estimate the accuracy of redshifts inferred from the multicolor photometry. From the test with simulated galaxies, the uncertainty in the inferred re

Xu Zhou, Zhaoji Jiang, Jun Ma, Suijian Xue

In this paper, we present a set of photometric observations in 15 colors of stars in the Landolt covered by the system range from 300 nm to 1000 nm. Visual magnitudes of the stars being studied in the field are from 10th to 20th mag. The observational methodology and the data reduction procedures are described. The relationships between the BATC intermediate

A. Gromov, Yu. Baryshev, P. Teerikorpi

Recent observations support the view that the universe is described by a FLRW model with $Ω_m^0 \approx 0.3$, $Ω_Λ^0 \approx 0.7$, and $w \leq -1/3$ at the present epoch. There are several theoretical suggestions for the cosmological $Λ$ component and for the particular form of the energy transfer between this dark energy and matter. This gives a strong moti

P. C. Frisch, H. Mueller, G. Zank, C. Lopate

Interstellar material surrounding an extrasolar planetary system interacts with the stellar wind to form the stellar astrosphere, and regulates the properties of the interplanetary medium and cosmic ray fluxes throughout the system. Advanced life and civilization developed on Earth during the time interval when the Sun was immersed in the vacuum of the Local

Mordecai-Mark Mac Low

MHD turbulence plays a central role in the physics of star-forming molecular clouds and the interstellar medium. I here show that MHD turbulence in molecular clouds must be driven to account for the observed supersonic motions in the clouds, as even strongly magnetized turbulence decays quickly. I then show that driven MHD turbulence can globally support gra

Bahram Mashhoon

The helicity-rotation coupling and its current empirical basis are examined. The modification of the Doppler effect due to the coupling of photon spin with the rotation of the observer is considered in detail in connection with its applications in the Doppler tracking of spacecraft. Further implications of this coupling and the possibility of searching for i

Debabrata Panja

Recently it has been shown that when an equation that allows so-called pulled fronts in the mean-field limit is modelled with a stochastic model with a finite number $N$ of particles per correlation volume, the convergence to the speed $v^*$ for $N \to \infty$ is extremely slow -- going only as $\ln^{-2}N$. However, this convergence is seen only for very hig

Mark D. Roberts

The paths of stars in galaxies have circular velocity independent of their distance from the centre of the galaxy. Newtonian mechanics with a logarithmic potential has such paths. In relativity these paths can be taken to be geodesics and this requirement places a resticting equation on the spacetime metric. This equation has a non-unique spherically symmetr

Ken-ichi Maruno, Adrian Ankiewicz, Nail Akhmediev

Using Painlevé analysis, the Hirota multi-linear method and a direct ansatz technique, we study analytic solutions of the (1+1)-dimensional complex cubic and quintic Swift-Hohenberg equations. We consider both standard and generalized versions of these equations. We have found that a number of exact solutions exist to each of these equations, provided that t

J. A. Gonzalez, L. Trujillo, A. Escalante

We address the problem of the relative importance of the intrinsic chaos and the external noise in determining the complexity of population dynamics. We use a recently proposed method for studying the complexity of nonlinear random dynamical systems. The new measure of complexity is defined in terms of the average number of bits per time-unit necessary to sp

H. Shojaie, M. Farhoudi

We consider the effect of the \emph{Varying Speed of Light} theory on non-rotating black holes. We show that in any varying-$c$ theory, the Schwarzschild solution is neither static nor stationary. For a no-charged black hole, the singularity in the Schwarzschild horizon cannot be removed by coordinate transformation. Hence, no matter can enter the horizon, a

M. C. Nucci

A transformation is derived which takes Lorenz integrable system into the well-known Euler equations of a free-torque rigid body with a fixed point, i.e. the famous motion à la Poinsot. The proof is based on Lie group analysis applied to two third order ordinary differential equations admitting the same two-dimensional Lie symmetry algebra. Lie&#39;s classif

Michael E. Kellman

It is argued that the standard quantum mechanical description of the Bell correlations between entangled subsystems is in conflict with relativistic space-time symmetry. Proposals to abandon relativistic symmetry, in the sense of explicitly returning to an absolute time and preferred frame, are rejected on the grounds that the preferred frame is not empirica

A. P. C. Malbouisson

Using the non-perturbative method of {\it dressed} states introduced in previous publications [N.P.Andion, A.P.C. Malbouisson and A. Mattos Neto, J.Phys.{\bf A34}, 3735, (2001); G. Flores-Hidalgo, A.P.C. Malbouisson, Y.W. Milla, Phys. Rev. A, {\bf 65}, 063314 (2002)], we study the evolution of a confined quantum mechanical system embedded in a {\it ohmic} en

Sameen Ahmed Khan, Ramaswamy Jagannathan, Rajiah Simon

The Foldy-Wouthuysen iterative diagonalization technique is applied to the Helmholtz equation to obtain a Hamiltonian description of the propagation of a monochromatic quasiparaxial light beam through a system in which the refractive index $n(x,y,z)$ varies about a background value $n_0$ such that $|n(x,y,z)-n_0| \ll n_0$. This technique is presented as an a

C. Adami

Artificial Life provides the opportunity to study the emergence and evolution of simple ecosystems in real time. We give an overview of the advantages and limitations of such an approach, as well as its relation to individual-based modeling techniques. The Digital Life system Avida is introduced and prospects for experiments with ab initio evolution (evoluti

H. Grigorian, D. Blaschke, G. Poghosyan

We have found correlations between properties of the equation of state for stellar matter with a phase transition at supernuclear densities and two characteristic features of a &#34;phase diagram&#34; for rotating compact stars in the angular velocity - baryon number plane: 1) the critical dividing line between mono- and two-phase star configurations and 2)

Marianna Euler, Norbert Euler, Niclas Petersson

In our article &#34;A tree of linearisable second-order evolution equations by generalised hodograph transformations&#34; [J. Nonlin. Math. Phys. {\bf 8} (2001), 342-362] we presented a tree of linearisable (C-integrable) second-order evolution equations in (1+1) dimensions. Expanding this result we report here the complete set of recursion operators for thi

Stephen C. Anco

A class of new nonabelian gauge theories for vector fields on three manifolds is presented. The theories describe a generalization of three-dimensional Yang-Mills theory featuring a novel nonlinear gauge symmetry and field equations for Lie-algebra valued vector potential fields. The nonlinear form of the gauge symmetry and field equations relies on the vect

Craig Huneke, Yongwei Yao

We give a new and simple proof that unmixed local rings having Hilbert-Kunz multiplicity equal to 1 must be regular.

Tadeusz Januszkiewicz, Jarek Kedra

We construct characteristic classes of smooth (Hamiltonian) fibrations as as fiber integrals of products of Pontriagin (or Chern) classes of vertical vector bundles over the total space of the universal fibration. We give explicit formulae of these fiber integrals for toric manifolds and get estimates of the dimension of the cohomology groups of classifying

Atsushi Moriwaki

Let X be a projective scheme over a finite field. In this paper, we consider the asymptotic behavior of the number of effective cycles on X with bounded degree as it goes to the infinity. By this estimate, we can define a certain kind of zeta functions associated with groups of cycles. We also consider an analogue in Arakelov geometry.

Charles Frohman, William H. Meeks

We give a complete topological classification of minimal surfaces in Euclidian three-space.

Les Reid, Leslie G. Roberts, Marie A. Vitulli

In this article we investigate when a homogeneous ideal in a graded ring is normal, that is, when all positive powers of the ideal are integrally closed. We are particularly interested in homogeneous ideals in an N-graded ring generated by all homogeneous elements of degree at least m and monomial ideals in a polynomial ring over a field. For ideals of the f

Shinya Sakuma, Hiroshi Yamauchi

In this article we study a VOA with two Miyamoto involutions generating $S_3$. In \cite{M3}, Miyamoto showed that a VOA generated by two conformal vectors whose Miyamoto involutions generate an automorphism group isomorphic to $S_3$ is isomorphic to one of the four candidates he listed. We construct one of them and prove that our VOA is actually the same as

Hiroshi Yamauchi

We study intertwining operators among the twisted modules for rational VOAs and show the modular invariance property of the space spanned by the trace functions concerning to some representations of rational orbifold VOAs. Our result generalizes the results obtained by Dong-Li-Mason and Miyamoto, which are basically extensions of Zhu&#39;s celebrated works.

F. Loran

We show that a given set of first class constraints becomes abelian if one maps each constraint to the surface of other constraints. There is no assumption that first class constraints satisfy a closed algebra. The explicit form of the projection map is obtained at least for irreducible first class constraints. Using this map we give a method to obtain gauge

Gordon Chalmers

A unified theory of four-dimensional gravity together with the standard model is presented, with supersymmetry breaking of M-theory at a TeV. Masses of the the known particles are derived. The cosmological constant is quantum generated to the observed value. Quantum corrections to the classical compactification are analyzed, and the scenario is stable.

Shihao Chen

On the basis of a new quantum field theory without divergence presented by us we identify W-matter with dark matter and guess that the two new stars RXJ1865 and 3C58 and quasi-stellar objects are the compounds of a F-celestial body with a W-celestial body with massive enough mass, and some earthquakes, some tsunamis and some disasters in some areas like Berm

S. Fajfer, P. Singer, J. Zupan

We present a calculation of the rare decay modes D^0 -> e^+ e^- gamma and D^0 -> mu^+ mu^- gamma in the framework of Standard Model. For the short distance part, we have derived QCD corrections to the Wilson coefficients involved, including C_9. The latter is found to be strongly suppressed by the corrections, leading to diminished values for the c -> u l^+l

Prashanth Jaikumar, Ismail Zahed

We study the spectrum of scalar-isoscalar excitations in the color-flavor locked phase of dense quark matter. The sigma meson in this phase appears as a four-quark state (of diquark and anti-diquark) with a well-defined mass and extremely small width, as a consequence of it&#39;s small coupling to two pions. The quark particle/hole degrees of freedom also co

L. Verozub, A. Kochetov

Testing of the gravitation equations, proposed by one of the authors earlier, by a binary pulsar is considered. It has been shown that the formulas for the gravitation radiation of the system resulting from the equations do not contradict the available observations data.

Adam P. Micolich

Negatively biased surface-gates allow electrostatic depletion of selected regions of a 2DEG, forming confined regions of specific geometry called billiards, in which ballistic transport occurs. At millikelvin temperatures, the electron phase coherence length is sufficient that quantum interference effects produce reproducible magneto-conductance fluctuations

C. F. Huang

It is shown in this paper that the quantum master equation can be mapped to a modified continuous time random walk (CTRW) if the relaxation term is composed of transitions over a set of states. When the Hamiltonian is time-independent and transitions are between its eigenlevels, such a modified CTRW reduces to the Markovian walk equivalent to the Pauli maste

Judith G. Cohen, Charles R. Lawrence, Roger D. Blandford

We present a secure redshift of z=0.944\pm0.002 for the lensed object in the Einstein ring gravitational lens B0218+357 based on five broad emission lines, in good agreement with our preliminary value announced several years ago based solely on the detection of a single emission line.

John P. Ralston, Soebur Razzaque, Pankaj Jain

Cosmic rays in the regime of 10^19-10^20 eV should not exist, according to the GZK bound. Conflicts between data and the bound have led to suggestions that laws of physics must be modified. We find that physical processes neglected in the early history terminate the LPM effect, important in calibrating the energy of electromagnetic and hadronic showers in th

D. Horns, the HEGRA collaboration

Recent results obtained with the HEGRA system of imaging Cherenkov telescopes on the TeV emission of the Blazars Mkn~421 ($z=0.030$), 1ES1959+650 ($z=0.047$), and H1426+428 ($z=0.129$) are reported. For Mkn~421, a close connection of the average flux level and spectral shape has been observed during the periods of increased activity in the years 2000 and 200

Nozomu Kawakatu, Masayuki Umemura, Masao Mori

Based on the radiation hydrodynamical model for the black hole(BH) growth,incorporated with the chemical evolution of the early-type host galaxy, we construct the coevolution model of a QSO BH and the host galaxy. As a result, it is found that after a galactic wind epoch,the luminosity is shifted from the host-dominant phase to the AGN-dominant phase (QSO ph

Craig J. Hogan

Requiring black hole evaporation to be quantum-mechanically coherent imposes a universal, finite ``holographic bound&#39;&#39;, conjectured to be due to fundamental discreteness of quantized gravity, on the amount of information carried by any physical system. This bound is applied to the information budget in the standard slow-roll model of cosmic inflation

E. Athanassoula

I follow a bar from its formation, via its evolution, to its destruction and, perhaps, regeneration. I discuss the main features at each stage and particularly the role of the halo. Bars can form even in sub-maximum discs. In fact, such bars can be stronger than bars which have grown in maximum discs. This is due to the response of the halo and, in particula

Andrzej Karbowski

In the note an error in Low and Lapsley&#39;s article (&#34;Optimization Flow Control, I: Basic Algorithm and Convergence&#34;, IEEE/ACM Transactions on Networking, 7(6), pp. 861-874, 1999) is pointed out. Because of this error the proof of the Theorem 2 presented in the article is incomplete and some assessments are wrong. In the second part of the note the

Andrzej Karbowski

In the note two errors in Low and Lapsley&#39;s article &#34;Optimization Flow Control, I: Basic Algorithm and Convergence&#34;, &#34;IEEE/ACM Transactions on Networking&#34;, 7(6), pp. 861-874, 1999, are shown. Because of these errors the proofs of both theorems presented in the article are incomplete and some assessments are wrong.

Andrew W. Blain, V. E. Barnard, Scott C. Chapman

The spectral energy distributions (SEDs) of dusty high-redshift galaxies are poorly sampled in frequency and spatially unresolved. Their form is crucially important for estimating the large luminosities of these galaxies accurately, for providing circumstantial evidence concerning their power sources, and for estimating their redshifts in the absence of spec

M. D&#39;Elia, M. -P. Lombardo

We study QCD at nonzero temperature and baryon density in the framework of the analytic continuation from imaginary chemical potential. We carry out simulations of QCD with four flavor of staggered fermions, and reconstruct the phase diagram in the temperature-imaginary μplane. We consider ansätze for the analytic continuation of the critical line and other

J. N. Fuchs, O. Prevote, D. M. Gangardt

We consider a trapped ultra-cold gas of (non-condensed) bosons with two internal states (described by a pseudo spin) and study the stability of a longitudinal pseudo spin polarization gradient. For this purpose, we numerically solve a kinetic equation corresponding to a situation close to an experiment at JILA. It shows the presence of Castaing&#39;s instabi

Sergei Shadrin

In this paper we study relations between intersection numbers on moduli spaces of curves and Hurwitz numbers. First, we prove two formulas expressing Hurwitz numbers of (generalized) polynomials via intersections on moduli spaces of curves. Then we show, how intersection numbers can be expressed via Hurwitz numbers. And then we obtain an algorithm expressing

Markus A. Luty, Nobuchika Okada

We construct an explicit 5-dimensional supergravity model that realizes the &#34;no scale&#34; mechanism for supersymmetry breaking with no unstable moduli. Supersymmetry is broken by a constant superpotential localized on a brane, and the radion is stabilized by Casimir energy from supergravity and massive hypermultiplets. If the standard model gauge and ma

Olga V. Babourova, Boris N. Frolov

The perfect dilaton-spin fluid (as a model of the dilaton matter, the particles of which are endowed with intrinsic spin and dilaton charge) is considered as the source of the gravitational field in a Weyl-Cartan spacetime. The variational theory of such fluid is constructed and the dilaton-spin fluid energy-momentum tensor is obtained. The variational forma

V. Batarin, T. Brennan, J. Butler, H. Cheung

The energy dependence of the energy and position resolutions of the electromagnetic calorimeter prototype made of lead tungstate crystals produced in Bogoroditsk (Russia) and Shanghai (China) is presented. These measurementswere carried out at the Protvino accelerator using a 1 to 45 GeV electron beam. The crystals were coupled to photomultiplier tubes. The

J. T. Mendonca, Vitor Cardoso

Nonlinear wave interaction of low amplitude gravitational waves in flat space-time is considered. Analogy with optics is established. It is shown that the flat metric space-time is equivalent to a centro-symmetric optical medium, with no second order susceptibility. The lowest order nonlinear effects are those due to the third order nonlinearity and include

Yu. G. Pogorelov, V. R. Shaginyan

We show that a strongly correlated Fermi system with the fermion condensate, which exhibits strong deviations from Landau Fermi liquid behavior, is driven into the Landau Fermi liquid by applying a small magnetic field $B$ at temperature T=0. This field-induced Landau Fermi liquid behavior provides the constancy of the Kadowaki-Woods ratio. A reentrance into

Nobunari Kashikawa, Tadafumi Takata, Youichi Ohyama, Michitoshi Yoshida

We have constructed a very deep K&#39;-selected multicolor BVRIz&#39;JK&#39; sample of 439 field galaxies. Photometric redshifts for sample galaxies were estimated. The overall redshift distribution N(z) for the K&#39;<21.0 sample is consistent with previous observations, and for the first time we derive the N(z) down to K&#39;=24.0. After taking account of

M. Markevitch, M. W. Bautz, B. Biller, Y. Butt

We present an exploratory Chandra ACIS-S3 study of the diffuse component of the Cosmic X-ray Background in the 0.3-7 keV band for four directions at high Galactic latitudes, with emphasis on details of the ACIS instrumental background modeling. Observations of the dark Moon are used to model the detector background. A comparison of the Moon data and the data

Robert B. Griffiths

Any attempt to introduce probabilities into quantum mechanics faces difficulties due to the mathematical structure of Hilbert space, as reflected in Birkhoff and von Neumann&#39;s proposal for a quantum logic. The (consistent or decoherent) histories solution is provided by its single framework rule, an approach that includes conventional (Copenhagen) quantu

Asher Peres

If the fine structure constant is not really constant, is this due to a variation of $e$, $\hbar$, or $c$? It is argued that the only reasonable conclusion is a variable speed of light.

Mauricio Ayala

We make a short study of the history and evolution of scientific publications, in order to explain the format for near-term e-Prints servers, proposing a new scientific publication scheme via digital network, and exploring the new dynamics of publication.

Thomas R. Hemmert

Some open topics in the field of low energy photon-nucleon interactions are discussed--which in my opinion are of interest both for obtaining new information on nucleon structure as well as for precision tests of our theoretical understanding of chiral dynamics. In particular, I discuss p-wave multipoles in charged pion photoproduction off protons as well as

Yoshiharu Mori, Koichi Saito

Using a purely hadronic model, we study the charge-symmetry-breaking $ρ$-$ω$, $σ$-$δ$, $σ$-$ρ$ and $δ$-$ω$ mixing amplitudes in isospin asymmetric nuclear matter. The basic assumption of the model is that the mixing amplitude is generated by nucleon and anti-nucleon loops and hence driven entirely by the difference between proton and neutron Fermi momenta an