July 2000 arXiv papers — page 19

V. Lengyel, Yu. Fekete, I. Haysak, A. Shpenik

The spin - spin mass splitting of light, heavy and mixed mesons are described within a good accuracy in the potential model with screened potential. We conclude that the long - distance part of the potential cannot be pure scalar and that a vector - scalar mixture is favoured. With the same parameters which gives correct average mass spectrum excellent spin

S. Dalley

The transverse lattice approach to non-perturbative light-front hamiltonian QCD is described. Preliminary results on the pi-rho system are presented, at fixed DLCQ and Tamm-Dancoff cut-offs. A renormalised, approximately Lorentz covariant light-front hamiltonian is found to leading order of the colour-dielectric expansion, compatible with a massless pion. Th

Xiao-Gang He, Jenq-Yuan Leou, Chung-Yi wu

We study effects of new physics beyond the Standard Model on SU(3) symmetry in charmless hadronic two body B decays. It is found that several equalities for some of the decay amplitudes, such as $A(B_d (B_u) \to π^+π^-,π^+ K^- (π^- \bar K^0)) =A(B_s \to K^+ π^-, K^- K^+ (K^0 \bar K^0))$, $A(B_d \to π^+ρ^-, π^- ρ^+, K^-ρ^+, π^+ K^{*-}) = A(B_s \to K^+ ρ^-, π^

Mark Srednicki

I discuss the validity of the quantum Boltzmann equation for the calculation of WIMP relic densities.

S. Capitani, L. Giusti

The renormalization of the most general dimension-six four-fermion operators without power subtractions is studied at one loop in lattice perturbation theory using overlap fermions. As expected, operators with different chirality do not mix among themselves and parity-conserving and parity-violating multiplets renormalize in the same way. The renormalization

W. Bardeen, A. Duncan, E. Eichten, H. Thacker

A study of the chiral behavior of pseudoscalar masses and decay constants is carried out in quenched lattice QCD with Wilson fermions. Using the modified quenched approximation (MQA) to cure the exceptional configuration problem, accurate results are obtained for pion masses as low as $\approx$ 200 MeV. The anomalous chiral log effect associated with quenche

The WA102 Collaboration, D. Barberis

A partial wave analysis of the centrally produced eta pi0 and eta pi- channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. Clear a0(980) and a2(1320) signals have been observed in S and D+ waves respectively. The dPT, phi and |t| distributions of these resonances are presented.

James D. E. Grant

The author has removed this paper, following the publication of a more complete version.

Vasiliki Pavlidou, Konstantinos Tassis, Thomas W. Baumgarte, Stuart L. Shapiro

We systematically study late-time tails of scalar waves propagating in neutron star spacetimes. We consider uniform density neutron stars, for which the background spacetime is analytic and the compaction of the star can be varied continously between the Newtonian limit 2M/R << 1 and the relativistic Buchdahl limit 2M/R = 8/9. We study the reflection of a fi

Robert D. Klauber

Non-time-orthogonal analysis of rotating frames is applied to objects in gravitational orbits and found to be internally consistent. The object&#39;s surface speed about its axis of rotation, but not its orbital speed, is shown to be readily detectable by any &#34;enclosed box&#34; experimenter on the surface of such an object. Sagnac type effects manifest r

Paweł~Nurowski, Jerzy F. Plebański

A maximally reduced system of equations corresponding to the twisting type N Einstein metrics is given. When the cosmological constant $λ\to 0$ they reduce to the standard equations for the vacuum twisting type N&#39;s. All the metrics which are conformally equivalent to the twisting type N metrics and which admit 3-dimensional conformal group of symmetries

Shahar Hod

Bekenstein and Mukhanov have put forward the idea that, in a quantum theory of gravity a black hole should have a discrete mass spectrum with a concomitant {\it discrete} line emission. We note that a direct consequence of this intriguing prediction is that, compared with blackbody radiation, black-hole radiance is {\it less} entropic. We calculate the ratio

Ted Herman

Phase clocks are synchronization tools that implement a form of logical time in distributed systems. For systems tolerating transient faults by self-repair of damaged data, phase clocks can enable reasoning about the progress of distributed repair procedures. This paper presents a phase clock algorithm suited to the model of transient memory faults in asynch

M. D. Glinchuk, E. A. Eliseev, V. A. Stephanovich, L. Jastrabik

The equations for phase transitions temperatures, order parameters and critical concentrations of components have been derived for mixed ferroelectrics. The electric dipoles randomly distributed over the system were considered as a random field sources. We derive a random field distribution function for different orientations of the electric dipoles with non

Yeong-Ah Soh, G. Aeppli, N. D. Mathur, M. G. Blamire

We report the discovery of mesoscale regions with distinctive magnetic properties in epitaxial La$_{1-x}$Sr$_{x}$MnO$_{3}$ films which exhibit tunneling-like magnetoresistance across grain boundaries. By using temperature-dependent magnetic force microscopy we observe that the mesoscale regions are formed near the grain boundaries and have a different Curie

Pieder Beeli

While the electrodynamic treatment of a superconducting thin film by Yeh et al. [Phys. Rev. B 48, 9861 (1993)] ostensibly has application for the &#34;thin-film limit,&#34; their work is shown to employ bulk-like instead of thin-film electrodynamics, and as such obtains an ostensible violation of the first law of thermodynamics and a surface resistance indep

A. E. Jacobs, D. Mukamel, D. W. Allender

A Landau model is used to study the phase behavior of the surface layer for magnetic and cholesteric liquid crystal systems that are at or near a Lifshitz point marking the boundary between modulated and homogeneous bulk phases. The model incorporates surface and bulk fields and includes a term in the free energy proportional to the square of the second deri

Sean R. Garner, Jason N. Hancock, Yvonne W. Rodriguez, Zack Schlesinger

Infrared, visible and near-UV reflectivity measurements are used to obtain conductivity as a function of temperature and frequency in YbInCu_4, which exhibits an isostructural phase-transition into a mixed-valent phase below T_v=42 K. In addition to a gradual loss of spectral weight with decreasing temperature extending up to 1.5 eV, a sharp resonance appear

L. L. Bonilla, J. Soler

A reduced drift-diffusion (Smoluchowski-Poisson) equation is found for the electric charge in the high-field limit of the Vlasov-Poisson-Fokker-Planck system, both in one and three dimensions. The corresponding electric field satisfies a Burgers equation. Three methods are compared in the one-dimensional case: Hilbert expansion, Chapman-Enskog procedure and

Yu. E. Lozovik, I. V. Ovchinnikov

The novel method of observation and controlling of Bose-Einstein condensation in the system of spatially and momentum-space indirect excitons in coupled quantum wells using in-plane magnetic and normal electric fields is proposed. Fields are used for exciton dispersion engeneering. In the presence of in-plane magnetic field ground state of spatially indirect

O. A. Petrenko, G. Balakrishnan, M. R. Lees, D. McK Paul

The high magnetic field behaviour of the triangular lattice antiferromagnet CuFeO_2 is studied using single crystal neutron diffraction measurements in a field of up to 14.5 T and also by magnetisation measurements in a field of up to 12 T. At low temperature, two well-defined first order magnetic phase transitions are found in this range of applied magnetic

D. Herman, H. Mathur, A. J. Dahm

The damping of quantum effects in the transport properties of electrons deposited on a surface of liquid helium is studied. It is found that due to vertical motion of the helium vapour atoms the interference of paths of duration $t$ is damped by a factor $\exp - (t/τ_v)^3$. An expression is derived for the weak-localization lineshape in the case that damping

L. N. Bulaevskii, E. M. Chudnovsky

We study the equilibrium domain structure and magnetic flux around a ferromagnetic (FM) film with perpendicular magnetization M_0 on a superconducting (SC) substrate. At 4πM_0<H_{c1} the SC is in the Meissner state and the equilibrium domain width in the film, l, scales as (l/4πλ_{L}) = (l_{N}/4πλ_{L})^{2/3} with the domain width on a normal (non-superconduc

A. Kambili, A. B. Walker

We investigate hole transport in polymer light-emitting-diodes in which the emissive layer is made of liquid-crystalline polymer chains aligned perpendicular to the direction of transport. Calculations of the current as a function of time via a random-walk model show excellent qualitative agreement with experiments conducted on electroluminescent polyfluoren

Tai Kai Ng, Derek K K Lee

We investigate the possibility of finding a zero-temperature metallic phase in granular superconducting films. We are able to identify the breakdown of the conventional treatment of these systems as dissipative Bose systems. We do not find a metallic state at zero temperature. At finite temperatures, we find that the system exhibit crossover behaviour which

R. Mathieu, P. Svedlindh, P. Nordblad

Magnetic, electric and structural properties of La$_{0.96-y}$Nd$_y$K$_{0.04}$MnO$_{3+δ}$ with 0$\leq y \leq$0.4 have been studied experimentally. A disordered magnetic state is formed as La is substituted by Nd, reflecting the competition between ferromagnetic (FM) double exchange and antiferromagnetic superexchange interactions. Key structural parameters ar

Richard J. Mathar

We calculate the &#34;head&#34; element or the (0,0)-element of the wave-vector and frequency-dependent dielectric matrix of bulk crystals via first-principles, all-electron Kohn-Sham states in the integral of the irreducible polarizability in the random phase approximation. We approximate the macroscopic &#34;head&#34; element of the inverse matrix by its r

A. Recati, F. Zambelli, S. Stringari

The rotational motion of an interacting Bose-Einstein condensate confined by a harmonic trap is investigated by solving the hydrodynamic equations of superfluids, with the irrotationality constraint for the velocity field. We point out the occurrence of an overcritical branch where the system can rotate with angular velocity larger than the oscillator freque

X. H. Zheng

The Hamiltonian and trial function in the BCS theory are improved to test the limit of this theory. The Cooper pairs arise from standing electron waves, ready to move with atoms, giving high Tc. The Hamiltonian is derived from alternating layers of light and heavy atoms, giving a forbidden zone hosting no standing wave pairs. The exchange term may force sing

David A. Kessler, Herbert Levine

We study the effect of general nonlinear force laws in viscoelastic lattice models of fracture, focusing on the existence and stability of steady-state Mode III cracks. We show that the hysteretic behavior at small driving is very sensitive to the smoothness of the force law. At large driving, we find a Hopf bifurcation to a straight crack whose velocity is

U. Zeitler, H. W. Schumacher, A. G. M. Jansen, R. J. Haug

We observe pronounced transport anisotropies in magneto-transport experiments performed in the two-dimensional electron system of a Si/SiGe heterostructure. They occur when an in-plane field is used to tune two Landau levels with opposite spin to energetic coincidence. The observed anisotropies disappear drastically for temperatures above 1 K. We propose tha

L. B. Ioffe, A. V. Lopatin

We discuss mean field theory of glasses without quenched disorder focusing on the justification of the replica approach to thermodynamics. We emphasize the assumptions implicit in this method and discuss how they can be verified. The formalism is applied to the long range Ising model with orthogonal coupling matrix. We find the one step replica-symmetry brea

M. E. Zhitomirsky, A. Honecker, O. A. Petrenko

We predict that an external field can induce a spin order in highly frustrated classical Heisenberg magnets. We find analytically stabilization of collinear states by thermal fluctuations at a one-third of the saturation field for kagome and garnet lattices and at a half of the saturation field for pyrochlore and frustrated square lattices. This effect is st

Frank C. van den Bosch, Julianne J. Dalcanton

We discuss a comparison of models for the formation of disk galaxies both in a Universe dominated by cold dark matter (CDM) and one in which the force law is given by modified Newtonian dynamics (MOND). Our main aim is to address the claim made by McGaugh & de Blok that CDM suffers from severe fine-tuning problems, which are circumvented under MOND. As we sh

V. Avila-Reese, C. Firmani, E. D&#39;Onghia, X. Hernandez

Using observational data for a sample of dark matter dominated galaxies and two cluster of galaxies, we have found that the central halo density does not depend on its mass, and the core radius is roughly proportional to the maximum rotation velocity. A good agreement with these scaling laws is obtained for CDM halos whose dense inner parts were expanded by

B. Semelin, F. Combes

The interstellar medium is observed in a hierarchical fractal structure over several orders of magnitude in scale. Aiming to understand the origin of this structure, we carry out numerical simulations of molecular cloud fragmentation, taking into account self-gravity, dissipation and energy input. Self-gravity is computed through a tree code, with fully or q

F. Fiore, L. A. Antonelli, P. Ciliegi, A. Comastri

The BeppoSAX 4.5-10 keV High Energy Large Area Survey has covered about 80 square degrees of sky down to a flux of F(5-10keV)~5E-14 cgs. Optical spectroscopic identification of about half of the sources in the sample (62) shows that many (~50%) are highly obscured AGN, in line with the predictions of AGN synthesis models for the hard X-ray background (XRB, s

R. Pello, M. Bolzonella, J. F. Le Borgne, J. P. Kneib

We review the use of photometric redshifts in the particular context of Gravitational Telescopes. We discuss on the possible application of such a technique to the study of both the faint population of distant sources and the properties of cluster lenses. Photometric reshifts could be used to derive the redshift distribution and properties of a very faint su

Donald Lynden-Bell

Evolution with mass segregation and the evolution of the rotation of cores are both discussed for self-similar core collapse. Evolution with angular velocity proportional to the square root of the density is predicted. On the Dynamical Main Sequence of globular clusters the energy emission from binaries balances the energy expended in expanding the halo. New

Irini Sakelliou

In clusters of galaxies, the reaction of the intracluster medium (ICM) to the motion of the co-existing galaxies in the cluster triggers the formation of unique features, which trace their position and motion. Galactic wakes, for example, are an apparent result of the ICM/galaxy interactions, and they constitute an important tool for deciphering the motion o

Felipe Menanteau, Roberto G. Abraham, Richard S. Ellis

We investigate the dispersion in the internal colours of faint spheroidals in the HDFs North and South. We find that a remarkably large fraction ~30% of the morphologically classified spheroidals with I<24 mag show strong variations in internal colour, which we take as evidence for recent episodes of star-formation. In most cases these colour variations mani

A. Retter, T. Naylor

Archival data on permanent superhump systems are compiled to test the thermal stability of their accretion discs. We find that their discs are almost certainly thermally stable as expected. This result confirms Osaki&#39;s suggestion (1996) that permanent superhump systems form a new subclass of cataclysmic variables (CVs), with relatively short orbital peri

L. Sidoli, S. Mereghetti, A. Treves, L. Chiappetti

The BeppoSAX satellite performed a survey of the Galactic Center Region in the 1-10 keV energy band with its Narrow Field Instruments. Several bright X-ray sources containing neutron stars and black holes have been observed and studied, including the possible counterpart of SgrA*. Here we report the results on the diffuse emission coming from the SgrA Comple

Michael L. Balogh, Simon L. Morris

We present the results of a search for strong H-alpha emission line galaxies (rest frame equivalent widths greater than 50 A) in the z=0.23 cluster Abell 2390. The survey contains 1189 galaxies over 270 square arcminutes, and is 50% complete at M_r=-17.5+5 log h. The fraction of galaxies in which H-alpha is detected at the 2sigma level rises from 0.0 in the

Rainer Dick

In his pioneering work on singular shells in general relativity, Lanczos had derived jump conditions across energy-momentum carrying hypersurfaces from the Einstein equation with codimension 1 sources. However, on the level of the action, the discontinuity of the connection arising from a codimension 1 energy-momentum source requires to take into account two

J. A. Brooke, P. Busch, D. B. Pearson

We explore commutativity up to a factor, $AB=λBA$, for bounded operators in a complex Hilbert space. Conditions on the possible values of the factor $λ$ are formulated and shown to depend on spectral properties of the operators involved. Commutativity up to a unitary factor is considered for pairs of self-adjoint operators. Examples of nontrivial realization

Boris E. Stern, Andrei M. Beloborodov, Juri Poutanen

A very high activity of Cygnus X-1 on 1999 April 19-21 was recorded by BATSE Large Area Detectors onboard the Compton Gamma-Ray Observatory. The peak luminosity was one order of magnitude higher than the normal luminosity of Cyg X-1. This fact can be critical for models of the hard state of Cyg X-1. The longest outburst lasted ~1000 s and demonstrated very u

Jen-Chi Lee

We calculate the NS-R fermionic zero-norm states of type II string spectrum. The massless and some possible massive zero-norm states are identified to be responsible for the space-time supersymmetry. The existence of other fermionic massive zero-norm states with higher spinor-tensor indices correspond to new enlarged boson-fermion symmetries of the theory at

Satoshi Yamaguchi

We investigate a Gepner-like superstring model described by a combination of multiple minimal models and an N=2 Liouville theory. This model is thought to be equivalent to the superstring theory on a singular noncompact Calabi-Yau manifold. We construct the modular invariant partition function of this model, and confirm the validity of an appropriate GSO pro

Yariv Kafri, David Mukamel, Luca Peliti

We study a model for the denaturation transition of DNA in which the molecules are considered as composed of a sequence of alternating bound segments and denaturated loops. We take into account the excluded-volume interactions between denaturated loops and the rest of the chain by exploiting recent results on scaling properties of polymer networks of arbitra

C. Bachas, J. Hoppe, B. Pioline

We consider the following two problems: classical domain walls in the $N=1^*$ mass deformation of the maximally supersymmetric Yang Mills theory, and D-strings as external magnetic sources in the context of the AdS/CFT correspondence. We show that they are both described by Nahm's equations with unconventional boundary conditions, and analyze the relevant mo

T. C. Ralph

We discuss a quantum key distribution scheme in which small phase and amplitude modulations of CW light beams carry the key information. The presence of EPR type correlations provides the quantum protection. We identify universal constraints on the level of shared information between the intended receiver (Bob) and any eavesdropper (Eve) and use this to make

U. D. Jentschura, G. Soff, P. J. Mohr

The fine structure interval of P states in hydrogenlike systems can be determined theoretically with high precision, because the energy levels of P states are only slightly influenced by the structure of the nucleus. Therefore a measurement of the fine structure may serve as an excellent test of QED in bound systems or alternatively as a means of determining

O. Oron, L. P. Horwitz

It has been shown by Gupta and Padmanabhan that the radiation reaction force of the Abraham-Lorentz-Dirac equation can be obtained by a coordinate transformation from the inertial frame of an accelerating charged particle to that of the laboratory. We show that the problem may be formulated in a flat space of five dimensions, with five corresponding gauge fi

B. G. Sidharth

The attempts to unify electromagnetism and gravitation have included the formulations of Herman Weyl and the Kaluza Klein theory with the fifth dimension. More recently there have been fruitful attempts in the domain of Quantum Superstrings and the author&#39;s formulation in terms of Quantum Mechanical Kerr-Newman Black Holes. Though all these appear to be

B. G. Sidharth

In this paper we consider black holes from a non general relativistic perspective as also from a microphysical point of view.

Lee Rudolph

Let F be R or C, d the dimension of F over R. Denote by P(F) either the affine plane A(F) or the hyperbolic plane H(F) over F. An arrangement L of k lines in P(F) (pairwise non-parallel in the hyperbolic case) has a link at infinity K(L) comprising k unknotted (d-1)-spheres in the (2d-1)-sphere, whose topology reflects the combinatorics of L `at infinity&#39

Sergey Pekarsky, Steve Shkoller

An explicit expression is obtained for the sectional curvature in the plane spanned by two stationary flows, cos(k, x) and cos(l, x). It is shown that for certain values of the wave vectors k and l the curvature becomes positive for alpha > alpha_0, where 0 < alpha_0 < 1 is of the order 1/k. This suggests that the flow corresponding to such geodesics becomes

Daniel Allcock, James A. Carlson, Domingo Toledo

Recall that the moduli space of smooth (that is, stable) cubic curves is isomorphic to the quotient of the upper half plane by the group of fractional linear transformations with integer coefficients. We establish a similar result for stable cubic surfaces: the moduli space is biholomorphic to a quotient of the compex 4-ball by an explict arithmetic group ge

David De Wit

This paper describes a method to obtain state model parameters for an infinite series of Links-Gould link invariants LG^{m,n}, based on quantum R matrices associated with the (\dot{0}_m | \dotα_n) representations of the quantum superalgebras U_q[gl(m|n)]. Explicit details of the state models for the cases n=1 and m=1,2,3,4 are supplied. Some evaluations of t

A. Zotov

In his celebrated paper Kontsevich has proved a theorem which manifestly gives a quantum product (deformation quantization formula) and states that changing coordinates leads to gauge equivalent star products. To illuminate his procedure, we make an arbitrary change of coordinates in the Moyal product and obtain the deformation quantization formula up to the

Juan Fernando Ospina Giraldo

The Wess-Zumino couplings for generalized sigma-orbifold fixed-points are presented and the generalized GS 6-form that encoding the complete sigma-standard gauge-gravitational-non standard gauge anomaly and its opposite inflow is derived.

W. de Boer, M. Huber, A. Gladyshev, D. I. Kazakov

New NLO b->sgamma calculations have become available. We observe that at large tanbeta the dominant NLO term of the chargino amplitude, which is proportional to mu.tanbeta^2, changes the sign of this amplitude in a large region of the CMSSM parameter space, so that the preferred sign of the Higgs mixing parameter mu now agrees with the preferred sign of b-ta

Joao P Silva

In the presence of CP violation, the effective Hamiltonian matrix describing a neutral meson anti-meson system does not commute with its hermitian conjugate. As a result, this matrix cannot be diagonalized by a unitary transformation and one needs to introduce a reciprocal basis. Although known, this fact is seldom discussed and almost never used. Here, we u

The OPAL collaboration, G Abbiendi

The photon structure function F2-gamma(x,Q**2) has been measured using data taken by the OPAL detector at centre-of-mass energies of 91Gev, 183Gev and 189Gev, in Q**2 ranges of 1.5 to 30.0 GeV**2 (LEP1), and 7.0 to 30.0 GeV**2 (LEP2), probing lower values of x than ever before. Since previous OPAL analyses, new Monte Carlo models and new methods, such as mul

The OPAL collaboration, G. Abbiendi

We compared the multiplicities of pizero, eta, Kzero and of charged particles in quark and gluon jets in 3-jet events, as measured by the OPAL experiment at LEP. The comparisons were performed for distributions unfolded to 100% pure quark and gluon jets, at an effective scale Qjet which took into account topological dependences of the 3-jet environment. The

The OPAL collaboration, G. Abbiendi

The data recorded at a centre-of-mass energy of 189GeV by the OPAL detector at LEP are used to search for trilinear couplings of the neutral gauge bosons in the process e+e- --> Z-gamma. The cross-sections are measured for multihadronic events with an energetic isolated photon and for events with a high energy photon accompanied by missing energy. These cros

The OPAL collaboration, G. Abbiendi

The inclusive production rate of phi mesons from the decay of b hadrons produced in Z0 decays was measured to be Br(b->phi+X) = 0.0282+-0.0013(stat.)+-0.0019(syst.), using data collected by the OPAL detector at LEP.

Kur. Myrzakul, R. Myrzakulov

The connection between multidimensional soliton equations and three-dimensional Riemann space is discussed.

Michael J. O&#39;Donnell, Ilia Bisnovatyi

Computing practice today depends on visual output to drive almost all user interaction. Other senses, such as audition, may be totally neglected, or used tangentially, or used in highly restricted specialized ways. We have excellent audio rendering through D-A conversion, but we lack rich general facilities for modeling and manipulating sound comparable in q

Barbara Coluzzi, Giorgio Parisi, Paolo Verrocchio

In ref. cond-mat/0005372, Sastry studies by numerical simulations the phase diagram of a simple fragile glass-forming liquid, presenting very interesting and clear results. We apply to this system, at various density values, the analytic approach to structural glass thermodynamics recently introduced and we compare our theoretical predictions on the liquid-g

Robert Englman, Asher Yahalom

Availability of short, femtosecond laser pulses has recently made feasible the probing of phases in an atomic or molecular wave-packet (superposition of energy eigenstates). With short duration excitations the initial form of the wave-packet is an essentially real &#34;doorway state&#34;, and this develops phases for each of its component amplitudes as it ev

Amir Levinson

The idea that the TeV air showers, thought to be produced by >10 TeV gamma rays from Mrk 501, can be mimicked by coherent bunches of sub-TeV photons is reexamined, focusing on fundamental considerations. In particular, it is shown that the minimum spot size of the beam of pulsed TeV photons arriving at Earth is on the order of a few kilometers, unless a lens

Susana Landau, Pablo Sisterna, Hector Vucetich

It has been recently claimed that cosmologies with time dependent speed of light might solve some of the problems of the standard cosmological scenario, as well as inflationary scenarios. In this letter we show that most of these models, when analyzed in a consistent way, lead to large violations of charge conservation. Thus, they are severly constrained by

Luis Anchordoqui, Carlos Nunez, Kasper Olsen

In this paper we study the creation of brane-worlds in $AdS$ bulk. We first consider the simplest case of onebranes in $AdS_3$. In this case we are able to properly describe the creation of a spherically symmetric brane-world deriving a general expression for its wavefunction. Then, we sketch the $AdS_{d+1}$ set-up within the context of the WKB approximation

M. Schlosser

We give elementary derivations of some classical summation formulae for bilateral (basic) hypergeometric series. In particular, we apply Gauss&#39; 2-F-1 summation and elementary series manipulations to give a simple proof of Dougall&#39;s 2-H-2 summation. Similarly, we apply Rogers&#39; nonterminating 6-phi-5 summation and elementary series manipulations to

A. Raiteri

A realistic interpretation of Schroedinger and Dirac equations for density matrices is proposed, in which the difference between the position arguments of the density matrix is considered as an objective extra space dimension. &#34;Particle&#34; solutions are found, which are perfectly localized both in position space and in momentum space (the position and

M. V. Altaisky

The biological hierarchy and the differences between living and non-living matter are considered from the standpoint of quantum mechanics.

Predrag L. Stojkov, Milivoj R. Belic, Marko V. Jaric

Various algebraic structures of degenerate four-wave mixing equations of optical phase conjugation are analyzed. Two approaches (the spinorial and the Lax-pair based), complementary to each other, are utilized for a systematic derivation of conserved quantities. Symmetry groups of both the equations and the conserved quantities are determined, and the corres

M. Yu. Kuchiev, V. N. Ostrovsky

Harmonic generation by an atom in a laser field is described by the three-step mechanism as proceeding via above-threshold ionization (ATI) followed by the electron propagation in the laser-dressed continuum and the subsequent laser assisted recombination (LAR). An amplitude of harmonic production is given by the coherent sum of contributions from different

G. Kurizki, A. E. Kozhekin, T. Opatrny, B. Malomed

The properties of optical solitons in periodic nonlinear media are reviewed. The emphasis is on solitons in periodically refractive media (Bragg gratings) incorporating a periodic set of thin layers of two-level systems resonantly interacting with the field. Such media support a variety of bright and dark `gap solitons&#39; propagating in the band gaps of th

David B. Massey

The characteristic cycle of a complex of sheaves on a complex analytic space provides weak information about the complex; essentially, it yields the Euler characteristics of the hypercohomology of normal data to strata. We show how perverse cohomology actually allows one to extract the individual Betti numbers of the hypercohomology of normal data to strata,

Andrew Kricker

This work identifies a class of moves on knots which translate to $m$-equivalences of the associated $p$-fold branched cyclic covers, for a fixed $m$ and any $p$ (with respect to the Goussarov-Habiro filtration.) These moves are applied to give a flexible (if specialised) construction of knots for which the Casson-Walker-Lescop invariant (for example) of the

G. T. Ter-Kazarian

The operator manifold formalism (part I) enables the unification of the geometry and the field theory, and yields the quantization of geometry. This is the mathematical framework for our physical outlook that the geometry and fields, with the internal symmetries and all interactions, as well the four major principles of relativity (special and general), quan

Osamu Yasuda

Superkamiokande atmospheric neutrino data for 990 days are analyzed in the framework of four neutrinos without imposing constraints of Big Bang Nucleosynthesis. It is shown that the wide range of the oscillation parameters is allowed at 90% confidence level ($0.1\lsim |U_{s1}|^2+|U_{s2}|^2\le 1$).

B. A. Berg, H. Markum, R. Pullirsch, T. Wettig

We compare the low-lying spectrum of the staggered Dirac operator in the confining phase of compact U(1) gauge theory on the lattice to predictions of chiral random matrix theory. The small eigenvalues contribute to the chiral condensate similar as for the SU(2) and SU(3) gauge groups. Agreement with the chiral unitary ensemble is observed below the Thouless

Antonio Badolato, Francesco Giazotto, Marco Lazzarino, Pasqualantonio Pingue

The impact of junction transparency in driving phase-coherent charge transfer across diffusive semiconductor-superconductor junctions is demonstrated. We present conductivity data for a set of Nb-InAs junctions differing only in interface transparency. Our experimental findings are analyzed within the quasi-classical Green-function approach and unambiguously

Anatoly Svidzinsky, Alexander Fetter

We consider a large condensate in a rotating anisotropic harmonic trap. Using the method of matched asymptotic expansions, we derive the velocity of an element of vortex line as a function of the local gradient of the trap potential, the line curvature and the angular velocity of the trap rotation. This velocity yields small-amplitude normal modes of the vor

Y. Mizuno, K. Tsutsui, T. Tohyama, S. Maekawa

We theoretically study the nonlinear optical response and photoexcited states of the Mott insulators. The nonlinear optical susceptibility χ^(3) is calculated by using the exact diagonalization technique on small clusters. From the systematic study of the dependence of χ^(3) on dimensionality, we find that the spin-charge separation plays a crucial role in e

G. Tagliaferri, G. Ghisellini, M. Ravasio, A. Celotti

We present the results of two ToO BeppoSAX observations of BL Lac. During the first observation we detected both the synchrotron and the Compton components. Fast time variability was present, but only for the synchrotron component. During the second observation the spectrum was flatter and only the Compton component was present. Four different SED are presen

Giorgio Matt, Fulvio Pompilio, Fabio La Franca

The energy density of the Cosmic X-ray background (XRB) peaks around 30 keV (see Figure 1), an energy not yet probed by focussing imaging instruments. The first hard X-ray telescope due to fly on a space mission will be that on board Constellation-X. The imaging capability, besides providing an improvement of several orders of magnitude in sensitivity over c

Giorgio Matt

Recent results on the X-ray spectrum and variability of Seyfert 1 galaxies are reviewed. New spectral results from BeppoSAX observations are also presented and briefly discussed.

U. Schwarzkopf, R. -J. Dettmar

We present the second part of a detailed statistical study focussed on the effects of tidal interactions and minor mergers on the radial and vertical disk structure of spiral galaxies. In the first part we reported on the sample selection, observations, and applied disk models. In this paper the results are presented, based on disk parameters derived from a

U. Schwarzkopf, R. -J. Dettmar

This paper is the first part in our series on the influence of tidal interactions and minor mergers on the radial and vertical disk structure of spiral galaxies. We report on the sample selection, our observations, and data reduction. Surface photometry of the optical and near infrared data of a sample of 110 highly-inclined/edge-on disk galaxies are present

Matias Zaldarriaga, Uros Seljak, Lam Hui

We investigate correlations between the long wavelength fluctuations and the small scale power in the Lyman alpha forest. We show that such correlations can be used to discriminate between fluctuations induced by large scale structure and those produced by non-gravitational processes such as fluctuations in the continuum of the quasar or in the temperature o

Glenn D. Starkman, Dejan Stojkovic, Tanmay Vachaspati

Zero modes of massive standard model fermions have been found on electroweak Z-strings. A zero mode solution for a massless left-handed neutrino is also known, but was thought to be non-normalizable. Here we show that although this mode is not discretely normalizable, it is delta-function normalizable and the correct interpretation of this solution is within

A. Chamblin, A. Karch, A. Nayeri

We analyze the thermodynamical properties of brane-worlds, with a focus on the second model of Randall and Sundrum. We point out that during an inflationary phase on the brane, black holes will tend to be thermally nucleated in the bulk. This leads us to ask the question: Can the black hole - brane-world system evolve towards a configuration of thermal equil

Stacey Hobbs, Peter K. S. Dunsby

Assuming a large-scale homogeneous magnetic field, we follow the covariant and gauge-invariant approach used by Tsagas and Barrow to describe the evolution of density and magnetic field inhomogeneities and curvature perturbations in a matter-radiation universe. We use a two parameter approximation scheme to linearize their exact non-linear general-relativist

P. Lecheminant, T. Jolicoeur, P. Azaria

The one-dimensional spin-S $J_1-J_2$ XY model is studied within the bosonization approach. Around the two limits ($J_2/J_1 \ll 1,J_2/J_1 \gg 1$) where a field theoretical analysis can be derived, we discuss the phases as well as the different phase transitions that occur in the model. In particular, it is found that the chiral critical spin nematic phase, fi

T. Hahn

The complete O(α) corrections including soft-photon bremsstrahlung to the process e^+ e^- -> W^+ W^- in the MSSM are calculated for on-shell W bosons. The relative difference between the MSSM and Standard Model corrections is generally quite small. The maximum deviation from the Standard Model within the scanned region of parameter space is \lesssim 1.5% for