July 2002 arXiv papers — page 8

A. Yu. Smirnov, A. M. Zagoskin

We show that flux qubits can be efficiently entangled by inductive coupling to a tunable resonant circuit, in the scheme reminiscent of atoms' entanglement through the optical cavity mode. It is shown, in particular, that the single-photon excitation of the resonator produces the pure Bell state of qubits with the completely disentangled LC circuit.

Paolo Padoan, Stanislav Boldyrev, William Langer, AAke Nordlund

We compute the structure function scaling of the integrated intensity images of two J=1-0 13CO maps of Taurus and Perseus. The scaling exponents of the structure functions follow the velocity scaling of supersonic turbulence, suggesting that turbulence plays an important role in the fragmentation of cold interstellar clouds. The data also allows to verify th

M. Robberto, S. V. W. Beckwith, N. Panagia

We model the IR Spectral Energy Distribution of circumstellar disks embedded in a HII region and photoevaporated by the external UV radiation. The model applies to the photoevaporated disks (proplyds) in Orion Nebula. First we calculate the IR emission of a PMS star surrounded by a dusty globule that is immersed within an HII region. The globule is assumed t

Ashley P. Willis, Carlo F. Barenghi

Recent experiments have shown that it is possible to study a fundamental astrophysical process such as dynamo action in controlled laboratory conditions using simple MHD flows. In this paper we explore the possibility that Taylor-Couette flow, already proposed as a model of the magneto-rotational instability of accretion discs, can sustain generation of magn

James M. De Buizer, James T. Radomski, Robert K. Pina, Charles M. Telesco

We present high-resolution (<0.5&#34;) mid-infrared Keck II images of individual sources in the central region of NGC 6334 I. We compare these images to images at a variety of other wavelengths from the near infrared to cm radio continuum and speculate on the nature of the NGC 6334 I sources. We assert that the cometary shape of the UCHII region here, NGC 63

Ashley P. Willis, Carlo F. Barenghi

We study the magneto-rotational instability of an incompressible flow which rotates with angular velocity Omega(r)=a+b/r^2 where r is the radius and $a$ and b are constants. We find that an applied magnetic field destabilises the flow, in agreement with the results of Rudiger & Zhang 2001. We extend the investigation in the region of parameter space which is

Ashley P. Willis, Carlo F. Barenghi

We investigate magnetic Taylor--Couette flow in the presence of an imposed axial magnetic field. First we calculate nonlinear steady axisymmetric solutions and determine how their strength depends on the applied magnetic field. Then we perturb these solutions to find the critical Reynolds numbers for the appearance of wavy modes, and the related wavespeeds,

K. R. Sembach, B. P. Wakker, B. D. Savage, P. Richter

We report the results of an extensive FUSE study of high velocity OVI absorption along 102 complete sight lines through the Galactic halo. The high velocity OVI traces a variety of phenomena, including tidal interactions with the Magellanic Clouds, accretion of gas, outflow from the Galactic disk, warm/hot gas interactions in a highly extended Galactic coron

Sebastien Fromang, Steven A. Balbus

A simple variational calculation is presented showing that a uniformly rotating barotropic fluid in an external potential attains a true energy minimum if and only if the rotation profile is everywhere subsonic. If regions of supersonic rotation are present, fluid variations exist that could take the sytem to states of lower energy. In any given system, thes

Ashley P. Willis, Carlo F. Barenghi

Taylor--Couette flow in the presence of a magnetic field is a problem belonging to classical hydromagnetics and deserves to be more widely studied than it has been to date. In the nonlinear regime the literature is scarce. We develop a formulation suitable for solution of the full three dimensional nonlinear hydromagnetic equations in cylindrical geometry, w

P. Szkody, B. Gansicke, S. B. Howell, E. Sion

We have obtained Hubble Space Telescope UV spectra of the white dwarf in GW Lib, the only known non-radially pulsating white dwarf in a cataclysmic variable, and the first known DAZQ variable. The UV light curve reveals large amplitude (10%) pulsationsin the UV with the same periods (646, 376 and 237 s) as those seen at optical wavelengths, but the mean spec

Attila Meszaros

Two groups recently deduced the positive value for the cosmological constant, concluding at a high (>= 99%) confidence level that the Universe should be accelerating. This conclusion followed from the statistical analysis of dozens of high-redshift supernovae. In this paper this conclusion is discussed. From the conservative frequentist&#39;s point of view t

W. de Boer, C. Sander, M. Horn, D. Kazakov

We investigate, if the cosmic ray positron fraction, as reported by the HEAT and AMS collaborations, is compatible with the annihilation of neutralinos in the supergravity inspired Constrained Minimal Supersymmetric Model (CMSSM), thus complementing previous investigations, which did not consider constraints from unification, electroweak symmetry breaking an

N. G. Douglas, K. Kuijken, A. J. Romanowsky, M. R. Merrifield

We report here the successful commissioning of the PN.Spectrograph, the first special-purpose instrument for the measurement of galaxy kinematics through the PN population

Lev Titarchuk, Wei Cui, Kent Wood

We explain why it is possible to detect directly X-ray emission from near the surface of the neutron star (NS) in SAX J1808.4-3658 but not in most other low-mass X-ray binaries (LMXBs), with the exception that emission from the surface can be seen during bursts events. We show that the X-ray emission from SAX J1808.4-3658 mostly originates in the Comptonizat

E. Gallo, R. Fender, G. Pooley

Radio emission from X-ray binary systems (XRBs) has developed in recent years from being peculiar phenomenon to being recognised as an ubiquitous property of several classes of XRBs. In this scenario the synchrotron emission is interpreted as the radiative signature of jet-like outflows, some or all of which may possess relativistic bulk motion. We have anal

F. Reale

Two recent works have analyzed a solar large and steady coronal loop observed with Yohkoh/SXT in two filter passbands to infer the distribution of the heating along it. Priest et al. (2000) modelled the distribution of the temperature obtained from filter ratio method with an analytical approach, and concluded that the heating was uniform along the loop. Asc

Ralph Neuhaeuser, Eike Guenther, Wolfgang Brandner

We obtained optical and infrared spectra of Cha Ha 5/cc 1, a faint possibly sub-stellar companion candidate next to the M6-type brown dwarf candidate Cha Ha 5 in Cha I, using FORS1 and ISAAC at the VLT. The VRIJHK colors of Cha Ha 5/cc 1 are consistent with either an L-type companion or a K-type background giant. Our spectra show that the companion candidate

Ralph Neuhaeuser, Wolfgang Brandner, Joao Alves, Viki Joergens

We present results from a deep imaging search for companions around the young bona-fide and candidate brown dwarfs Cha Ha 1 to 12 in the Cha I dark cloud, performed with HST WFPC2 (R, I, Ha), VLT FORS1 (VRI), and NTT SofI (JHK). We find 16 faint companion candidates around five primaries with separations between 1.5&#34; and 7&#34; and magnitudes in R & I fr

J. Dyks, B. Rudak

We investigate the role of rotational effects in inducing asymmetry present above ~5 GeV in the double-peak lightcurves of the bright EGRET pulsars: Vela, Crab, and Geminga. According to Thompson 2001, the trailing peak dominates over the leading peak above ~5 GeV consistently for all three pulsars, even though this is not the case over the entire energy ran

L. Boirin, A. N. Parmar, T. Oosterbroek, D. Lumb

We have observed the X-ray transient XTE J0421+56 in quiescence with XMM-Newton. The observed spectrum is highly unusual being dominated by an emission feature at ~6.5 keV. The spectrum can be fit using a partially covered power-law and Gaussian line model, in which the emission is almost completely covered (covering fraction of 0.98_{-0.06}^{+0.02}) by neut

Silvano Molendi

We revisit the XMM-Newton observation of M87 focusing our attention on the temperature structure. We find that spectra for most regions of M87 can be adequately fit by single temperature models. Only in a few regions, which are cospatial with the E and SW radio arms, we find evidence of a second temperature. The cooler component (kT ~ 0.8-1 keV) fills a smal

G. Rüdiger, M. Küker, K. L. Chan

We measure the eddy viscosity in the outermost layers of the solar convection zone by comparing the rotation law computed with the Reynolds stress resulting from f-plane simulations of the angular momentum transport in rotating convection with the observed differential rotation pattern. The simulations lead to a negative vertical and a positive horizontal an

TOP Collaboration

The flux of cosmic ray hadrons at the atmospheric depth of 820 g/cm^2 has been measured by means of the EAS-TOP hadron calorimeter (Campo Imperatore, National Gran Sasso Laboratories, 2005 m a.s.l.). The hadron spectrum is well described by a single power law : S(E_h) = (2.25 +- 0.21 +- 0.34(sys)) 10^(-7)(E_h/1000)^(-2.79 +- 0.05) m^(-2) s^(-1) sr^(-1) GeV^(

Kerstin Weis

The most massive evolved stars (above 50 M_sun) undergo a phase of extreme mass loss in which their evolution is reversed from a redward to a blueward motion in the HRD. In this phase the stars are known as Luminous Blue Variables (LBVs) and they are located in the HRD close to the Humphreys-Davidson limit. It is far from understood what causes the strong ma

Kerstin Weis, Michael F. Corcoran, Kris Davidson, Roberta M. Humphreys

Eta Carinae is a very luminous and unstable evolved star. Outflowing material ejected during the star&#39;s giant eruption in 1843 surrounds it as a nebula which consists of an inner bipolar region(the Homunculus) and the Outer Ejecta. The outer ejecta is very filamentary and shaped irregularly. Kinematic analysis, however, shows a regular bi-directional exp

Dmitry Bizyaev, Sofija Mitronova

To analyze the vertical structure of edge-on galaxies, we have used images of a large uniform sample of flat galaxies that have been taken during the 2MASS all-sky survey. The photometric parameters, such as the radial scale length, the vertical scale height, and the deprojected central surface brightness of galactic disks have been obtained. We find a stron

J. Patience, R. J. White, A. M. Ghez, C. McCabe

A combination of high-resolution and wide-field imaging reveals two binary stars and one triple star system among the sample of the first 11 stars with planets detected by radial velocity variations. High resolution speckle or adaptive optics (AO) data probe subarcsecond scales down to the diffraction limit of the Keck 10-m or Lick 3-m, and direct images or

Roberto C. Gamen, Virpi S. Niemela

We present the discovery of OB type absorption lines superimposed to the emission line spectrum, and the first double-lined orbital elements for the massive Wolf-Rayet binary HDE 318016 (=WR 98), a spectroscopic binary in a circular orbit with a period of 47.825 days. The semiamplitudes of the orbital motion of the emission lines differ from line to line, in

Ewa L. Lokas

I review the main characteristics of structure formation in the quintessential Universe. Assuming equation of state w=p/\varrho=$const I provide a brief description of the background cosmology and discuss the linear growth of density perturbations, the strongly nonlinear evolution, the power spectra and rms fluctuations as well as mass functions focusing on

Ewa L. Lokas, Yehuda Hoffman

We generalize the spherical collapse model for the formation of bound objects to apply in a Universe with arbitrary positive cosmological constant. We calculate the critical condition for collapse of an overdense region and give exact values of the characteristic densities and redshifts of its evolution.

P. Bruno

The ``magnetic force theorem&#39;&#39; is frequently used to compute exchange interaction parameters and adiabatic spin-wave spectra of ferromagnets. The interest of this approach is that it allows to obtain these results from a non-self-consistent calculation of the (single-electron) band energy only, which greatly reduces the computational effort. However,

Nandor Simanyi

In this paper we study the ergodic properties of mathematical billiards describing the uniform motion of a point in a flat torus from which finitely many, pairwise disjoint, tubular neighborhoods of translated subtori (the so called cylindric scatterers) have been removed. We prove that every such system is ergodic (actually, a Bernoulli flow), unless a simp

Abhee K. Dutt-Mazumder

The bosonic excitations induced by the omega meson propagation in dense nuclear matter is studied within the framework of random phase approximation. The collective modes are then analyzed by finding the zeros of the relevant dielectric functions. Subsequently we present closed form analytical expressions for the dispersion relations in different kinematical

H. Muramatsu, CLEO Collaboration

In e^+e^- collisions using the CLEO detector we have studied the decay of the D^0 to the final state K_S^0 pi^+ pi^- with the initial flavor of the D^0 tagged in charged D^* decay. We use the Dalitz technique to measure the resonant substructure in this final state and clearly observe ten different contributions by fitting for their amplitudes and relative p

Shi-Lin Zhu, M. J. Ramsey-Musolf

We study the off-diagonal Goldberger-Treiman relation (ODGTR) and its discrepancy (ODGTD) in the N, Delta, pi sector through O(p^2) using heavy baryon chiral perturbation theory. To this order, the ODGTD and axial vector N to Delta transition radius are determined solely by low energy constants. Loop corrections appear at O(p^4). For low-energy constants of

F. Schrempp, A. Utermann

We pursue the intriguing possibility that larger-size instantons build up diffractive scattering, with the marked instanton-size scale <rho> approximately 0.5 fm being reflected in the conspicuous ``geometrization&#39;&#39; of soft QCD. As an explicit step in this direction, the known instanton-induced cross sections in deep-inelastic scattering (DIS) are tr

Shlomo Dado, Arnon Dar, Alvaro De Rujula

We use the very simple and successful Cannonball (CB) model of gamma ray bursts (GRBs) and their afterglows (AGs) to analyze the observations of the mildly extinct optical AG of the relatively nearby GRB 020405. We show that GRB 020405 was associated with a 1998bw-like supernova (SN) at the GRB&#39;s redshift that appeared dimmer and redder than SN1998bw bec

W. Janke, D. A. Johnston, Ranasinghe P. K. C. Malmini

It has been suggested that an information geometric view of statistical mechanics in which a metric is introduced onto the space of parameters provides an interesting alternative characterisation of the phase structure, particularly in the case where there are two such parameters -- such as the Ising model with inverse temperature $β$ and external field $h$.

Dragan Huterer, Glenn Starkman

Considerable work has been devoted to the question of how to best parameterize the properties of dark energy, in particular its equation of state w. We argue that, in the absence of a compelling model for dark energy, the parameterizations of functions about which we have no prior knowledge, such as w(z), should be determined by the data rather than by our i

Ketevi A. Assamagan, Aldo Deandrea, Pierre-Antoine Delsart

In the two Higgs doublet model type III and in several other extensions of the Standard Model, there are no discrete symmetries that suppress flavor changing couplings at tree level. The experimental observation of the nu_mu -- nu_tau flavor oscillation may suggest the non-conservation of lepton number. This would lead to the decay of the type A^0/H^0 --> ta

L. O. Manuel, C. J. Gazza, A. E. Feiguin, A. E. Trumper

We show theoretically the fingerprints of short-range spiral magnetic correlations in the photoemission spectra of the Mott insulating ground states realized in the triangular silicon surfaces K/Si(111)-B and SiC(0001). The calculated spectra present low energy features of magnetic origin with a reduced dispersion ~10-40 meV compared with the center-of-mass

Harald P. Pfeiffer, James W. York

The Einstein initial-value equations in the extrinsic curvature (Hamiltonian) representation and conformal thin sandwich (Lagrangian) representation are brought into complete conformity by the use of a decomposition of symmetric tensors which involves a weight function. In stationary spacetimes, there is a natural choice of the weight function such that the

N. Garcia, M. Nieto-Vesperinas, E. V. Ponizovskaya, M. Torres

In the moderately long wavelength propagation regime, acoustic crystaldevices which size is of several wave lengths are studied by using thefinite-difference time domain method. It is shown by the focusing and imaging of a square shaped lens that the diffractive effects dominate over the refractive ones. Taking into account the well known Babinet principle,

G. Penner, U. Mosel

We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), an

Yaron Oz, Tadakatsu Sakai

We study the Penrose limit of the (p,q) fivebranes supergravity background. We consider the different phases of the worldvolume field theory and their weakly coupled descriptions. In the Penrose limit we get a solvable string theory and compute the spectrum. It corresponds to states of the six-dimensional worldvolume theory with large energy and large U(1) c

A. Bassetto, F. Vian

We study the correlator of two parallel Wilson lines in two-dimensional noncommutative Yang-Mills theory, following two different approaches. We first consider a perturbative expansion in the large-N limit and resum all planar diagrams. The second approach is non-perturbative: we exploit the Morita equivalence, mapping the two open lines on the noncommutativ

S. J. Brodsky, V. S. Fadin, V. T. Kim, L. N. Lipatov

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is discussed. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in good agreement with recent OPAL and L3 data at CERN LEP2. NLO BFKL predictions for future linear colliders are prese

Y. Shimizu, M. Minowa, H. Sekiya, Y. Inoue

The quenching factor of the proton recoil in the stilbene scintillator was measured with a 252Cf neutron source and was found to be 0.1 - 0.17 in the recoil energy range between 300 keV and 3 MeV. It was found to depend on the direction of the recoil proton. The directional anisotropy of the quenching factor could be used to detect the wind of the WIMPs caus

J. Frauendiener, Matthias Hein

We describe in this article a new code for evolving axisymmetric isolated systems in general relativity. Such systems are described by asymptotically flat space-times which have the property that they admit a conformal extension. We are working directly in the extended `conformal&#39; manifold and solve numerically Friedrich&#39;s conformal field equations,

I. Scherbak

The hypergeometric solutions to the KZ equation contain a certain symmetric ``master function&#39;&#39;, [SV]. Asymptotics of the solutions correspond to critical points of the master function and give Bethe vectors of the inhomogeneous Gaudin model, [RV]. The general conjecture is that the number of orbits of critical points equals the dimension of the rele

F. A. Aharonian, A. Akhperjanian, M. Beilicke, Y. Uchiyama

Deep observation (~113 hrs) of the Cygnus region at TeV energies using the HEGRA stereoscopic system of air Cerenkov telescopes has serendipitously revealed a signal positionally inside the core of the OB association Cygnus OB2, at the edge of the 95% error circle of the EGRET source 3EG J2033+4118, and ~0.5deg north of Cyg X-3. The centre of gravity of the

Sadhan K. Adhikari

Using the explicit numerical solution of the axially-symmetric Gross-Pitaevskii equation we study the oscillation of the Bose-Einstein condensate induced by a periodic variation in the atomic scattering length $a$. When the frequency of oscillation of $a$ is an even multiple of the radial or axial trap frequency, respectively, the radial or axial oscillation

G. Penner, U. Mosel

We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), an

M. E. Gruner, E. Hoffmann, P. Entel

Based on ab initio total energy calculations we show that two magnetic states of rhodium atoms together with competing ferromagnetic and antiferromagnetic exchange interactions are responsible for a temperature induced metamagnetic phase transition, which experimentally is observed for stoichiometric alpha-FeRh. A first-principle spin-based model allows to r

H. O. Girotti, M. Gomes, A. Yu. Petrov, V. O. Rivelles

The spontaneous symmetry breaking of rotational O(N) symmetry in noncommutative field theory is investigated in a 2+1 dimensional model of scalar fields coupled through a combination of quartic and sextuple self-interactions. There are five possible orderings of the fields in the sextuple interaction and two for the quartic interaction. At one loop, we prove

Roberto Casero

We extend the BMN duality between IIB superstring theory on a pp-wave background and a sector of N=4 super Yang-Mills theory to the non-supersymmetric and unstable background built by Romans as a compactification on a U(1) bundle over CP2 with 3-form and 5-form field strength fluxes. We obtain a stable theory with the fewest number of supercharges (e.g. 16)

Mattias Christensson, Malcolm Fairbairn

We consider the dimming of photons from high redshift type 1a supernovae by mixing with a pseudoscalar axion field in the intergalactic medium. We model the electron density using a lognormal probability distribution and assume frozen in magnetic fields. Assuming the magnetic fields are produced in the early universe we are unable to obtain sufficient dimmin

Stefano Gabici, Pasquale Blasi

Nonthermal radiation is observed from clusters of galaxies in the radio, hard X-rays, and possibly in the soft X-ray/UV bands. While it is known that radiative processes related to nonthermal electrons are responsible for this radiation, the sites and nature of particle acceleration are not known. We investigate here the acceleration of protons and electrons

M. Brack, S. N. Fedotkin, A. G. Magner, M. Mehta

We present an analytical calculation of periodic orbits in the homogeneous quartic oscillator potential. Exploiting the properties of the periodic Lam{é} functions that describe the orbits bifurcated from the fundamental linear orbit in the vicinity of the bifurcation points, we use perturbation theory to obtain their evolution away from the bifurcation poin

Fazal-e-Aleem, Sohail Afzal Tahir

This paper has been withdrawn by the author due to a crucial errors.

P. Niezurawski, A. F. Zarnecki, M. Krawczyk

Production of the Standard Model Higgs-boson at the Photon Collider at TESLA is studied for the Higgs-boson masses above 150 GeV. Simulation of signal and background processes takes into account realistic luminosity spectra and detector effects. In the considered mass range, large interference effects are expected in the W+W- decay channel. By reconstructing

V. L. Chernyak

In many gauge theories at different values of parameters entering Lagrangian, the vacuum is dominated by coherent condensates of different mutually non-local fields (for instance, by condensates of electric or magnetic charges, or by various dyons). It is argued that the transition between these &#34;dual to each other&#34; phases proceeds through the interm

Probir Roy

Preliminary Remarks. Gauge mediated supersymmetry breaking. Gravity mediated supersymmetry breaking. Anomaly mediated supersymmetry breaking. Gaugino mediated supersymmetry breaking. Braneworld supersymmetry breaking. Conclusions.

Francesco De Martini, Andrea Mazzei, Marco Ricci, Giacomo Mauro D&#39;Ariano

The marriage of Quantum Physics and Information Technology, originally motivated by the need for miniaturization, has recently opened the way to the realization of radically new information-processing devices, with the possibility of guaranteed secure cryptographic communications, and tremendous speedups of some complex computational tasks. Among the many pr

S. J. van Enk

Quantum state discrimination for two coherent states with opposite phases as measured relative to a reference pulse is analyzed as functions of the intensities of both the signal states and of the reference pulse. This problem is relevant for Quantum Key Distribution with phase encoding. We consider both the optimum measurements and simple measurements that

A. B. Matsko, I. Novikova, G. R. Welch, M. S. Zubairy

We propose a new method of resonant enhancement of optical Kerr nonlinearity using multi-level atomic coherence. The enhancement is accompanied by suppression of the other linear and nonlinear susceptibility terms of the medium. We show that the effect results in a modification of the nonlinear Faraday rotation of light propagating in an Rb87 vapor cell by c

N. David Mermin

I explain what kinds of correlation or even direct classical communication between detectors invalidate Bell&#39;s theorem, and what kinds do not.

S. J. van Enk

We discuss several methods for unambiguous state discrimination of N symmetric coherent states using linear optics and photodetectors. One type of measurements is shown to be optimal in the limit of small photon numbers for any N. For the special case of N=4 this measurement can be fruitfully used by the receiving end (Bob) in an implementation of the BB84 q

W. Dür, R. Raussendorf, V. M. Kendon, H. -J. Briegel

We propose an experimental realization of discrete quantum random walks using neutral atoms trapped in optical lattices. The random walk is taking place in position space and experimental implementation with present day technology --even using existing set-ups-- seems feasible. We analyze the influence of possible imperfections in the experiment and investig

Conall Boyle, Roger Schafir

The prediction of the N-box paradox, that whichever box is opened will contain the record of the particle having passed through it, is traced to a failure to specify whether the other boxes are distinguishable or indistinguishable. These correspond to different ways of lifting the degeneracy of a certain measurement, and have incompatible consequences.

Nicholas D. Pattengale, Christopher K. Allen

A modular, maintainable and extensible particle beam simulation architecture is presented. Design considerations for single particle, multi particle, and rms envelope simulations (in two and three dimensions) are outlined. Envelope simulation results have been validated against Trace3D. Hybridization with a physics-centric contol-system abstraction provides

S. Jochim, M. Bartenstein, G. Hendl, J. Hecker Denschlag

We study elastic collisions in an optically trapped spin mixture of fermionic lithium atoms in the presence of magnetic fields up to 1.5kG by measuring evaporative loss. Our experiments confirm the expected magnetic tunability of the scattering length by showing the main features of elastic scattering according to recent calculations. We measure the zero cro

Konstantin P. Belyaev, Detlev Mueller

The feasibility of global ocean state estimation by sequential data assimilation is demonstrated. The model componenet of the assimilator is the GROB version of the MPIMET ocean circulation model HOPE. Assimilation uses the Fokker-Planck representation of the Kalman Filter. This approach determines the temporal evolution of error statistics by integration of

B. Bagchi, S. Mallik, C. Quesne

We examine the classical problem of an infinite square well by considering Hamilton&#39;s equations in one dimension and Hamilton-Jacobi equation for motion in two dimensions. We illustrate, by means of suitable examples, the nature of the periodic motion of a particle trapped inside the well.

R. Lisboa, M. Malheiro, A. Delfino, P. Alberto

Pseudospin symmetry in nuclei is investigated by solving the Dirac equation with Woods-Saxon scalar and vector radial potentials. We relate the pseudospin interaction with a pseudospin-orbit term in a Schroedinger-like equation for the lower component of the Dirac spinor. We show that this term gives a large contribution to the energy splittings of pseudospi

J. Lukasik, S. Hudan, F. Lavaud, K. Turzo

Invariant transverse-velocity spectra of intermediate-mass fragments were measured with the 4-pi multi-detector system INDRA for collisions of Au on Au at incident energies between 40 and 150 MeV per nucleon. Their scaling properties as a function of incident energy and atomic number Z are used to distinguish and characterize the emissions in (i) peripheral

K. -H. Schmidt, M. V. Ricciardi, A. Botvina, T. Enqvist

Isotope yields of heavy residues produced in collisions of 238U with lead at 1AGeV show indications for a simultaneous break-up process. From the average N-over-Z ratio of the final residues up to Z = 70, the average limiting temperature of the break-up configuration at freeze out was determined to T approximately 5 MeV using the isospin-thermometer method.

Peter Constantin

We consider the energy spectrum of a quasi-geostrophic model of forced, rotating turbulent flow. We provide a rigorous a priori bound E(k) <= Ck^{-2} valid for wave numbers that are smaller than a wave number associated to the forcing injection scale. This upper bound separates this spectrum from the Kolmogorov-Kraichnan k^{-{5/3}} energy spectrum that is ex

D. Jung, M. Luecke

Spatially confined solutions of traveling convection rolls are determined numerically for binary mixtures like ethanol-water. The appropriate field equations are solved in a vertical crossection of the rolls perpendicular to their axes subject to realistic horizontal boundary conditions. The localized convective states are stably and robustly sustained by st

J. C. Brunelli

Nonlinear dispersionless equations arise as the dispersionless limit of well know integrable hierarchies of equations or by construction, such as the system of hydrodynamic type. Some of these equations are integrable in the Hamiltonian sense and appear in the study of topological minimal models. In the first part of the review we will give a brief introduct

J. C. Brunelli, G. A. T. F. da Costa

A large class of nonlocal equations and nonlocal charges for the Harry Dym hierarchy is exhibited. They are obtained from nonlocal Casimirs associated with its bi-Hamiltonian structure. The Lax representation for some of these equations is also given.

J. Frauendiener

The Rarita-Schwinger equation in a curved background and an external electromagnetic field is discussed. We analyse the equation in the 2-component spinor formalism and derive Buchdahl conditions for them. The result is that the equation can consistently be imposed only on Einstein manifolds with vanishing electromagnetic field.

Yu. N. Kosovtsov

In present paper we propose an approach based on examination of the structure of the general solution of equations of the type dy/dx=P(x,y)/Q(x,y), with P and Q polynomials only in y. Under the term structure we mean the dependency character of solution from arbitrary constant. We describe a common form of the structures for foregoing equations. In such a wa

Shigeki Matsutani

A recursion relation of hyperelliptic psi functions of genus two, which was derived by D.G. Cantor (J. reine angew. Math. 447 (1994) 91-145), is studied. As Cantor&#39;s approach is algebraic, another derivation is presented as a natural extension of the analytic derivation of the recursion relation of the elliptic psi function.

Rafe Mazzeo, Frank Pacard

All complete, axially symmetric surfaces of constant mean curvature in R^3 lie in the one-parameter family D_tau of Delaunay surfaces. The elements of this family which are embedded are called unduloids; all other elements, which correspond to parameter value tau element in R^-, are immersed and are called nodoids. The unduloids are stable in the sense that

Herbert Gangl

We give the first genuine 2-variable functional equation for the 7--logarithm. We investigate and relate identities for the 3-logarithm given by Goncharov and Wojtkowiak and deduce a certain family of functional equations for the 4-logarithm.

Taehee Kim

It is known that if any prime power branched cyclic cover of a knot in the 3-sphere is a homology sphere, then the knot has vanishing Casson-Gordon invariants. We construct infinitely many examples of (topologically) non-slice knots in the 3-sphere whose prime power branched cyclic covers are homology spheres. We show that these knots generate an infinite ra

Peter Constantin

We consider uniformly rotating incompressible Euler and Navier-Stokes equations. We study the suppression of vertical gradients of Lagrangian displacement (&#34;vertical&#34; refers to the direction of the rotation axis). We employ a formalism that relates the total vorticity to the gradient of the back-to-labels map (the inverse Lagrangian map, for inviscid

Boris L. Granovsky

We establish a characterization of the class of the simplest nearest neighbor spin systems possesing the mean coverage function (mcf) that obeys a second order differential equation, and derive explicit expressions for the mcf&#39;s of the above models. Based on these expressions, the problem of ergodicity of the models is studied and bounds for their spectr

Maurice de Gosson

Gromov&#39;s nonsqueezing theorem, aka the property of the symplectic camel, leads to a very simple semiclassical quantiuzation scheme by imposing that the only &#34;physically admissible&#34; semiclassical phase space states are those whose symplectic capacity (in a sense to be precised) is nh + (1/2)h where h is Planck&#39;s constant. We the construct semi

Amnon Yekutieli

Let X be a scheme of finite type over a perfect field k. In this paper we study the relation between two important objects associated to X: the Grothendieck residue complex and the Beilinson adeles complex. It is known that the complex of adeles is a DGA (differential graded algebra). Our first main result is that the residue complex is a right DG module ove

J. Madore, M. Maceda, D. C. Robinson

We present a noncommutative version of a plane-wave solution to the gravitational field equations. We start with a given classical solution, admittedly rather simple, and construct an algebra and a differential calculus which supports the metric. In the particular solution presented as an example the 1-forms do not anticommute, to a degree which depends on t

Dmitri Antonov

(2+1)-dimensional Georgi-Glashow model and its SU(N)-generalization are explored at nonzero temperatures and in the regime when the Higgs boson is not infinitely heavy. The finiteness of the Higgs-boson mass leads to various novel effects. Those include the appearance of two separate phase transitions and of the upper bound on the parameter of the weak-coupl

Ian Davies, Paul Mansfield

Strings propagating in AdS_{D+1} are made Weyl invariant to leading order in large D by a ghost-matter coupling that preserves the Poincare symmetry of the boundary.

Kirill A. Kazakov

The question of Bohr correspondence in quantum field theory is considered from a dynamical point of view. It is shown that the classical description of particle interactions is inapplicable even in the limit of large particles&#39; masses because of finite quantum fluctuations of the fields produced. In particular, it is found that the relative value of the

B. P. Kosyakov

Exact solutions of classical gauge theories in even-dimensional (D=2n) spacetimes are discussed. Common and specific properties of these solutions are analyzed for the particular dimensions D=2, D=4, and D=6. A consistent formulation of classical gauge field theories with pointlike charged or colored particles is proposed for D=6. The particle Lagrangian mus

Nathan F. Lepora

This paper has been withdrawn.

Nathan F. Lepora

Withdrawn. Submittal to journal withdrawn by author in Dec 1999.

M. A. Braun, E. G. Ferreiro, C. Pajares, D. Treleani

We derive the inclusive transverse spectrum of minijets in nuclear collisions at very high energies by assuming that the nuclear S-matrix factorizes into a product of elastic S-matrices for elementary partonic collisions. Interference effects and, in particular, the contribution of loop diagrams are fully taken into account in the derivation of the spectrum,