November 1999 arXiv papers — page 4

Branislav Jurco, Peter Schupp

We develop a quantum Lax scheme for IRF models and difference versions of Calogero-Moser-Sutherland models introduced by Ruijsenaars. The construction is in the spirit of the Adler-Kostant-Symes method generalized to the case of face Hopf algebras and elliptic quantum groups with dynamical R-matrices.

Anjan Kundu

The inhomogeneity of the media or the external forces usually destroy the integrability of a system. We propose a systematic construction of a class of quantum models, which retains their exact integrability inspite of their explicit inhomogeneity. Such models include variable mass sine-Gordon model, cylindrical NLS, spin chains with impurity, inhomogeneous

Ph. Blanchard, A. Jadczyk, A. Ruschhaupt

In sections 1 and 2 we review Event Enhanced Quantum Theory (EEQT). In section 3 we discuss applications of EEQT to tunneling time, and compare its quantitative predictions with other approaches, in particular with Büttiker-Larmor and Bohm trajectory approach. In section 4 we discuss quantum chaos and quantum fractals resulting from simultaneous continuous m

G. Morigi, G. S. Agarwal

A model is developed to explain the temperature dependence of the group velocity as observed in the experiments of Hau et al (Nature {\bf397}, 594 (1999)). The group velocity is quite sensitive to the change in the spatial density. The inhomogeneity in the density and its temperature dependence are primarily responsible for the observed behavior.

Valeri V. Dvoeglazov

We show that the Gersten derivation of Maxwell equations can be generalized. It actually leads to additional solutions of `S=1 equations'. They follow directly from previous considerations by Majorana, Oppenheimer, Weinberg and Ogievetskii and Polubarinov. Therefore, {\it generalized} Maxwell equations should be used as a guideline for proper interpretat

Anthony Harkin, Ali Nadim, Tasso J. Kaper

The classical Blake threshold indicates the onset of quasistatic evolution leading to cavitation for gas bubbles in liquids. When the mean pressure in the liquid is reduced to a value below the vapor pressure, the Blake analysis identifies a critical radius which separates quasistatically stable bubbles from those which would cavitate. In this work, we analy

Shirley Booth, Ake Ingerman

We address the question "How do students make sense of Physics from the point of view of constituting physics knowledge?". A phenomenographic study is described as a result of which we present six qualitatively different ways in which students experience the first year of Physics. The variation is analysed in terms of the structure of experience, the

Zhong-Qi Ma

The exact solution to the Schrödinger equation for the rigid body with the given angular momentum and parity is obtained. Since the quantum rigid body can be thought of as the simplest quantum three-body problem where the internal motion is frozen, this calculation method is a good starting point for solving the quantum three-body problems.

Y. Abe, D. Boilley, B. G. Giraud, T. Wada

The diffusion problem over a saddle is studied using a multi-dimensional Langevin equation. An analytical solution is derived for a quadratic potential and the probability to pass over the barrier deduced. A very simple solution is given for the one dimension problem and a general scheme is shown for higher dimensions.

A. G. Ramm

Mathematically rigorous inversion method is developed to recover compactly supported potentials from the fixed-energy scattering data in three dimensions. Error estimates are given for the solution. An algorithm for inversion of noisy discrete fixed-energy #D scattering data is developed and its error estimates are obtained

R. Airapetyan, A. G. Ramm, A. Smirnova

A continuous analog of Gauss-Newton method for solving nonlinear ill-posed problems is proposed. Its converegence is proved. A numerical example is presented to demonstrate efficiency of the propsed method.

R. Airapetyan, A. G. Ramm, A. Smirnova

It is shown that the Newton-Sabatier procedure for inverting the fixed-energy phase shifts for a potential is not an inversion method but a parameter-fitting procedure. Theoretically there is no guarantee that this procedure is applicable to the given set of the phase shifts, if it is applicable, there is no guaran- tee that the potential it produces generat

George A. Hagedorn, Alain Joye

We prove six theorems concerning exponentially accurate semiclassical quantum mechanics. Two of these theorems are known results, but have new proofs. Under appropriate hypotheses, they conclude that the exact and approximate dynamics of an initially localized wave packet agree up to exponentially small errors in $\hbar$ for finite times and for Ehrenfest ti

Yu. A. Kubyshin

The classification problem for principal fibre bundles over two-dimensional CW-complexes is considered. Using the Postnikov factorization for the base space of a universal bundle a Puppe sequence that gives an implicit solution for the classification problem is constructed. In cases, when the structure group $G$ is path-connected or $π_{1}(G) = 0$, the class

Herve Guiol, Krishnamurthi Ravishankar, Ellen Saada

We describe the hydrodynamic behavior of the $k$-step exclusion process. Since the flux appearing in the hydrodynamic equation for this particle system is neither convex nor concave, the set of possible solutions include in addition to entropic shocks and continuous solutions those with contact discontinuities. We finish with a limit theorem for the tagged p

Wiland Schmale

A new and conceptually simple procedure is derived for the compu- tation of the maximal reachability submodule of a given submodule of the state space of a linear discrete time system over a Noethenian ring R. The procedure is effective if R is effective and if kernels and inter- sections can be computed. The procedure is compared with a rather different pro

Mikhail Grinenko

We discuss the rigidity problem for Mori fibrations on del Pezzo surfaces of degree 1, 2 and 3 over ${\mathbb P}^1$ and formulate the following conjecture: such a del Pezzo fibration $V/{\mathbb P}^1$ is birationally rigid if and only if its quasi-effective and adjunction thresholds coincide. We prove the "only if" part of this conjecture.

V. Manuilov, K. Thomsen

We show that the E-theory of Connes and Higson can be formulated in terms of C*-extensions in a way quite similar to the way in which the KK-theory of Kasparov can. The essential difference is that the role played by split extensions should be taken by asymptotically split extensions. We call an extension of a C*-algebra $A$ by a stable C*-algebra $B$ asympt

V. Ya. Fainberg, B. M. Pimentel

A strict proof of equivalence between Duffin-Kemmer-Petiau (DKP) and Klein-Gordon (KG) theories is presented for physical S-matrix elements in the case of charged scalar particles interacting in minimal way with an external or quantized electromagnetic field. First, Hamiltonian canonical approach to DKP theory is developed in both component and matrix form.

Mariusz P. Dabrowski

Bianchi type I and type IX ('Mixmaster') geometries are investigated within the framework of Hořava-Witten cosmology. We consider the models for which the fifth coordinate is a $S^1/Z_2$ orbifold while the four coordinates are such that the 3-space is homogeneous and has geometry of Bianchi type I or IX while the rest six dimensions have already been

Takuya Masuda, Satoru Saito

We construct operator representation of Moyal algebra in the presence of fermionic fields. The result is used to describe the matrix model in Moyal formalism, that treat gauge degrees of freedom and outer degrees of freedom equally.

E. J. Ferrer, V. de la Incera

Non-perturbative effects of constant magnetic fields in a Higgs-Yukawa gauge model are studied using the extremum equations of the effective action for composite operators. It is found that the magnetic field induces a Higgs condensate, a fermion-antifermion condensate, and a fermion dynamical mass, hence breaking the discrete chiral symmetry of the theory.

R. Fiore, L. L. Jenkovszky, V. Magas, F. Paccanoni

A model for a Regge trajectory compatible with the threshold behavior required by unitarity and asymptotics in agreement with Mandelstam analyticity is analyzed and confronted with the experimental data on the spectrum of the $ρ$ trajectory as well as those on the $π^- p\to π^0 n$ charge-exchange reaction. The fitted trajectory deviates considerably from a l

M. C. Banuls, A. Pich, I. Scimemi

The electromagnetic decays of the ground state baryon multiplets with one heavy quark are calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for S^{*}--> S gamma, S^{*} --> T gamma and S --> T gamma are separately computed. All M1 transitions are calculated up to O(1/Lambda_chi^2). The E2 amplitudes contribute at the same orde

L. E. Ibanez

In the past three years our views on how the standard model of particle physics could be embedded into string theory have dramatically changed. The heterotic string is no longer the only possibility for such an embedding and other perturbative (or non-perturbative) corners of M-theory, like Type I or Type II strings seem now possible. It has also been realiz

Pankaj Agrawal, Uma Mahanta

In this report we study how a light-scalar leptoquark could affect the Higgs boson production cross-section at the LHC collider. We construct the most general renormalizable and gauge invariant effective Lagrangian involving the standard model particles and a scalar, isoscalar leptoquark, η. The total cross-section for pp -> H+X is then calculated for differ

Toru Goto, Takeshi Nihei

We present results of reanalysis on proton decay in the minimal SU(5) SUSY GUT model. Unlike previous analyses, we take into account a Higgsino dressing diagram of dimension 5 operator with right-handed matter fields ($RRRR$ operator). It is shown that this diagram gives a significant contribution for $p \to K^{+}\barν_τ$. Constraints on the colored Higgs ma

Kazuo Fujikawa

We analyze the implications of the relation $Trγ_{5}=0$, which is customarily assumed in practical lattice calculations. On the basis of the finite dimensional representations of the Ginsparg-Wilson algebra, it is shown that this relation reflects the species doubling in lattice theory; topological excitations associated with species doublers, which have eig

James E. Brau

The precision measurements of lepton electroweak parameters at SLD and LEP are reviewed and discussed. The updated SLD weak mixing angle measurement from $A_{LR}$ and the lepton left-right forward-backward asymmetries is $\sin^2θ_W^{eff} = 0.23099 \pm 0.00026$, and the combined SLD/LEP lepton-based value is $0.23119 \pm 0.00020$. This value differs by over $

Marco Battaglia, Massimo Caccia

The e+e- linear collider physics programme sets highly demanding requirements on the accurate determination of charged particle trajectories close to their production point. A new generation of Vertex Trackers, based on different technologies of high resolution silicon sensors, is being developed to provide the needed performances. These developments are bas

B. Boisseau

By a weak deformation of the cylindrical symmetry of the potential vortex in a relativistic perfect isentropic fluid, we study the possible dynamics of the central line of this vortex. In "stiff" material the Nanbu-Goto equations are obtained

M. Azreg-Ainou, G. Clement, C. P. Constantinidis, J. C. Fabris

We investigate the family of electrostatic spherically symmetric solutions of the five-dimensional Kaluza-Klein theory. Both charged and neutral cases are considered. The analysis of the solutions, through their geometrical properties, reveals the existence of black holes, wormholes and naked singularities. A new class of regular solutions is identified. A m

Jeffrey Winicour

The characteristic initial value problem has been implemented as a robust computational algorithm (the PITT NULL CODE), with direct application to binary black holes. The event horizon can be analyzed by characteristic techniques as a stand-alone object using an analytic conformal model which gives new insight into the intrinsic geometry of binary black hole

C. Ungarelli, A. Vecchio

One of the most interesting predictions of string-inspired cosmological models is the presence of a stochastic background of relic gravitational waves in the frequency band accessible to Earth-based detectors. Here we consider a ``minimal'' class of string cosmology models and explore whether they are falsifiable by gravitational wave observations. I

S. V. Dhurandhar, A. Vecchio

We analyze the computational costs of searches for continuous monochromatic gravitational waves emitted by rotating neutron stars orbiting a companion object. As a function of the relevant orbital parameters, we address the computational load involved in targeted searches, where the position of the source is known; the results are applied to known binary rad

Jan Heering, Paul Klint

By paying more attention to semantics-based tool generation, programming language semantics can significantly increase its impact. Ultimately, this may lead to ``Language Design Assistants'' incorporating substantial amounts of semantic knowledge.

A. Johansen, H. Saleur, D. Sornette

Significant advances, both in the theoretical understanding of rupture processes in heterogeneous media and in the methodology for characterizing critical behavior, allows us to reanalyze the evidence for criticality and especially log-periodicity in the previously reported chemical anomalies that preceded the Kobe earthquake. The ion ($Cl^-$, $K^+$, $Mg^{++

Wolfhard Janke, Desmond A. Johnston

We investigate the non-self-averaging properties of the dynamics of Ising, 4-state Potts and 10-state Potts models in single-cluster Monte Carlo simulations on quenched ensembles of planar, trivalent Phi3 random graphs, which we use as an example of relevant quenched connectivity disorder. We employ a novel application of scaling techniques to the cumulative

S. M. Hayden, R. Doubble, G. Aeppli, T. G. Perring

Inelastic neutron scattering reveals strong spin fluctuations with energies as high as 0.4eV in the nearly antiferromagnetic metal Cr$_{0.95}$V$_{0.05}$. The magnetic response is well described by a modified Millis-Monien-Pines function. From the low-energy response, we deduce a large exchange enhancement, more than an order of magnitude larger than the corr

Sudip Chakravarty, Chetan Nayak

We consider a local moment which is coupled by a non-random Kondo $J$ to a band of conduction electrons in a random potential. We prove an analog of Anderson's theorem in a large-N limit of this model. The theorem states that when the disorder is weak, the disorder-averaged low-temperature thermodynamics is independent of the strength of the disorder; re

M. J. W. Dodgson, A. E. Koshelev, V. B. Geshkenbein, G. Blatter

We calculate the melting line of the pancake-vortex system in a layered superconductor, interpolating between two-dimensional (2D) melting at high fields and the zero-field limit of single-stack evaporation. Long-range interactions between pancake vortices in different layers permit a mean-field approach, the ``substrate model'', where each 2D crysta

A. Wallraff, Yu. Koval, M. Levitchev, M. V. Fistul

The interaction of a Josephson fluxon with an external magnetic field-induced potential in a long Josephson junction is investigated experimentally. The thermal activation of the fluxon from a potential well is observed and experiments probing its predicted quantum properties are discussed. A method for engineering a magnetic double-well potential for a flux

Matthieu H. Ernst

In two recent articles Salazar and Brenig question the validity of kinetic theory for granular gases and fluids, on the based of a supposedly exact hierarchy of coupled equations for the velocity moments, which the authors derive from the BBGKY-hierarchy. Their derivation contains several errors, which are exposed. Moreover, they support their findings with

X. Campi, H. Krivine, E. Plagnol, N. Sator

We show that the size distributions of fragments created by high energy nuclear collisions are remarkably well reproduced within the framework of a parameter free percolation model. We discuss two possible scenarios to explain this agreement and suggest that percolation could be an universal mechanism to explain the fragmentation of simple fluids.

F. Ladieu, D. L'Hôte, R. Tourbot

Variable range hopping transport has been investigated in amorphous YSi from 30 mK to 2 K as a function of the temperature T and electric field F. For F=0, where conduction is along sinuous paths (isotropic percolation), the conductance G depends on T according to an Efros-Shklovskii law. The nonlinear I-V's were studied up to very high fields for which

V. I. Tsebro, O. E. Omelyanovskii, A. P. Moravskii

It is found that the magnetization curves of samples of fragments of cathode carbon deposits with a high content of multiwalled nanotubes exhibit a pronounced irreversible character, attesting to the induction of persistent currents in the samples and to magnetic flux trapping, as happens in a multiply connected superconducting structure. A decrease of the t

A. O. Parry, C. Rascon, A. J. Wood

We show that continuous filling or wedge-wetting transitions are possible in 3D wedge-geometries made from (angled) substrates exhibiting first-order wetting transitions and develop a comprehensive fluctuation theory yielding a complete classification of the critical behaviour. Our fluctuation theory is based on the derivation of a Ginzburg criterion for fil

A. Ponzi, Y. Aizawa

We present our competing shares financial market model and describe its behaviour by numerical simulation. We show that in the critical region the distribution avalanches of the market value as defined in this model has a power-law distribution with exponent around 2.3. In this region the price returns distribution is truncated Levy stable with exponent near

Roland Haberkern

Quasicrystals are assumed to be electronically stabilized by a Hume-Rothery type mechanism. This explains most of the peculiar properties of quasicrystals. The stabilization is investigated by electronic transport properties, as they depend sensitively on the stabilizing interaction between the static structure and the conduction electrons. Thin-film techniq

C. -Y. David Lu, Peter D. Olmsted, R. C. Ball

We analyze the steady planar shear flow of the modified Johnson-Segalman model, which has an added non-local term. We find that the new term allows for unambiguous selection of the stress at which two ``phases'' coexist, in contrast to the original model. For general differential constitutive models we show the singular nature of stress selection in

Kazuo Hida

The low energy behavior of the S=1/2 antiferromagnetic XY-like XXZ chains with precious mean quasiperiodic exchange modulation is studied by the density matrix renormalization group method. It is found that the energy gap of the chain with length N scales as $\exp (-cN^ω)$ with nonuniversal exponent $ω$ if the Ising component of the exhange coupling is antif

J. L. Tallon, J. W. Loram, G. V. M. Williams

The impact of the normal-state pseudogap, present in all optimal and underdoped HTS cuprates, on critical currents and critical temperature is surveyed. With the opening of the pseudogap around a doping state of p=0.19 the condensation energy and superfluid density are rapidly suppressed due to reduction in the normal-state spectral weight. Even by optimal d

J. L. Tallon

Evidence is presented from NMR 1/T1T and ARPES data for the sudden disappearance of 2D antiferromagnetic (AF) correlations in the lightly overdoped region (p=0.19) at the T=0 metal-insulator transition where the pseudogap energy falls to zero. AF fluctuations thus appear to be intimately associated with the pseudogap and serve primarily to weaken superconduc

A. Mourachkine

Inelastic Neutron Scattering (INS) data in LSCO, YBCO and Bi2212 are discussed. In the literature, the INS spectra remain far from being comprehensively understood. We show that local (Q-integrated) susceptibility data and the energy dependence of the spin susceptibility at antiferromagnetic vector, Q = (p,p), can be interpreted by using the phase diagram fo

P. Markos

Metal-insulator transition in anisotropic disordered Anderson model with both topological and diagonal disorder is investigated numerically. For four sets of the model parameters we found the critical disorder and the critical exponent and prove that they do not depend on the transport direction. The system size independent critical conductance distribution

Valentin Gospodinov

This paper deals with the analytic derivation of a complete equation of state (EOS) for solids from shock-wave data in the range of pressures and temperatures, attained by detonation of chemical explosives. The caloric, the thermal and the incomplete EOS are determined as well. An equation for the shock temperature along the Hugoniot curve is derived also.

Huan-Qiang Zhou, Holger Frahm, Mark D. Gould

This paper has been withdrawn by the authors, due an error in Bethe Ansatz equations (16).

H. Boyaci, Z. Gedik, I. O. Kulik

Recently, it has been possible to construct single-electron transistors to study electronic properties, including superconductivity, in metallic grains of nanometer size. Among several theoretical results are suppression of superconductivity with decreasing grain size and parity effect, i.e. dependence on the parity of the number of electrons on the grain. W

I. Lehmann, G. Hasinger, M. Schmidt, J. E. Gunn

The ROSAT Deep Survey in the Lockman Hole contains a complete sample of 50 X-ray sources with fluxes in the 0.5-2.0 keV band larger than 5.5E-15 erg/cm2/s. Previous work has provided optical identification of 46 of the 50 X-ray sources; over 75% of the sources are AGNs (Schmidt et al. 1998). We present now the atlas of optical finding charts and the full des

Francois Legrand

Recent spectroscopic observations of IZw~18 have revealed homogeneous abundance throughout the galaxy and several observations of other starburst galaxies have shown no significant gradient or discontinuity in the abundance distributions within the HII regions. I thus concur with Tenorio-Tagle (1996) and Devost et al. (1997) that these observed abundance hom

N. D'Amico, A. G. Lyne, R. N. Manchester, F. M. Camilo

A high-frequency survey of the Galactic plane for radio pulsars is in progress, using the multibeam receiver on the 64-m Parkes radiotelescope. We describe the survey motivations, the observing plan and the inital results. The survey is discovering many pulsars, more than 500 so far. Eight of the new pulsars are binary, one with a massive companion. At least

Catarina Lobo, Angela Iovino, Guido Chincarini

We present a new automated cluster search algorithm, stressing its advantages relatively to others available in the literature. Applying it to the photometric data of the ESO Imaging Survey (EIS, Renzini & da Costa 1997) allowed us to produce, with a high degree of confidence, a new catalogue of cluster candidates up to z approximately equal to 1.1.

R. Ansari

EROS has been monitoring few million stars in the Magellanic clouds, as well as toward the Galactic bulge and spiral arms since 1996, to search for microlensing events. In this paper, we present briefly the EROS setup and scientific program and discuss the results obtained from our observations in four directions in the Galactic plane, away from the bulge. S

Jonathan Arons

I summarize the theory of acceleration of non-neutral particle beams by starvation electric fields along the polar magnetic field lines of rotation powered pulsars, including the effect of dragging of inertial frames which dominates the acceleration of a space charge limited beam. I apply these results to a new calculation of the radio pulsar death line, und

Esther M. Hu, Lennox L. Cowie, Richard G. McMahon

We review the properties of z>5 galaxies studied with HST and with the Keck telescopes, and discuss the detectability of Lyman alpha emission-line galaxies out to z~6.5 based on these data and ongoing narrowband imaging surveys. The brightest sources may show (R-Z) color breaks, although the high sky background at Z (lambda_{eff} ~ 9200 Ang), makes such obse

Y. Huang, A. Johansen, M. W. Lee, H. Saleur

The recently proposed discrete scale invariance and its associated log-periodicity are an elaboration of the concept of scale invariance in which the system is scale invariant only under powers of specific values of the magnification factor. We report on the discovery of a novel mechanism for such log-periodicity relying solely on the manipulation of data. T

G. Heinrich, G. Leibbrandt

We evaluate the coefficients of the leading poles of the complete two-loop quark self-energy Σ(p) in the Coulomb gauge. Working in the framework of split dimensional regularization, with complex regulating parameters σand n/2-σfor the energy and space components of the loop momentum, respectively, we find that split dimensional regularization leads to well-d

Shai Kaspi, Paul S. Smith, Hagai Netzer, Dan Maoz

(abridged) We have spectrophotometrically monitored a well-defined sample of 28 Palomar-Green quasars in order to obtain measurements of their BLRs and to investigate the relationships between quasar luminosity, central black hole mass, and broad emission line region (BLR) size in active galactic nuclei (AGN). Spectrophotometry was obtained every 1-4 months

Hou Defu, M. E. Carrington, R. Kobes, U. Heinz

We derive spectral representations for the different components of the 4-point function at finite temperature in the real time formalism in terms of five real spectral densities. We explicitly calculate all these functions in QED in the hard thermal loop approximation. The Ward identities obeyed by the 1-loop 3- and 4-point functions in real time and their s

P. Bozhilov

We consider null bosonic p-branes moving in curved space-times and develop a method for solving their equations of motion and constraints, which is suitable for string theory backgrounds. As an application, we give an exact solution for such background in ten dimensions.

Laurent Bartholdi, Rostislav I. Grigorchuk

We study the subgroup structure, Hecke algebras, quasi-regular representations, and asymptotic properties of some fractal groups of branch type. We introduce parabolic subgroups, show that they are weakly maximal, and that the corresponding quasi-regular representations are irreducible. These (infinite-dimensional) representations are approximated by finite-

Enrique D. Andjel, Pablo A. Ferrari, Herve Guiol, Claudio Landim

We consider a one-dimensional totally asymmetric nearest-neighbor zero-range process with site-dependent jump-rates - an environment. For each environment p we prove that the set of all invariant measures is the convex hull of a set of product measures with geometric marginals. As a consequence we show that for environments p satisfying certain asymptotic pr

A. Bassetto

Two different scenarios (light-front and equal-time) are possible for Yang-Mills theories in two dimensions. The exact $\bar q q$-potential can be derived in perturbation theory starting from the light-front vacuum, but requires essential instanton contributions in the equal-time formulation. In higher dimensions no exact result is available and, paradoxical

Robert A. Herrmann

In this paper, we investigate the algebras of consequence operators and finite consequence operators on a fixed language. Significant new collections of consequence operators are defined and shown to be complete and distributive sublattices. Further, the collection of consequence operators is shown to be almost atomic. Other lattice theoretic properties are

Frank Schweitzer, Janusz Holyst

The concept of active Brownian particles is used to model a collective opinion formation process. It is assumed that individuals in community create a two-component communication field that influences the change of opinions of other persons and/or can induce their migration. The communication field is described by a reaction-diffusion equation, the opinion c

Marcos Marino, Ruben Minasian, Gregory Moore, Andrew Strominger

Supersymmetric configurations of type II D-branes with nonzero gauge field strengths in general supersymmetric backgrounds with nonzero B fields are analyzed using the kappa-symmetric worldvolume action. It is found in dimension four or greater that the usual instanton equation for the gauge field obtains a nonlinear deformation. The deformation is parameter

I. Jack, D. R. T. Jones

We consider the renormalisation of the Fayet-Iliopoulos D-term in a softly-broken Abelian supersymmetric theory. We show that there exists (at least through three loops) a renormalisation group invariant trajectory for the coefficient of the D-term, corresponding to the conformal anomaly solution for the soft masses and couplings.

Toshiya Suzuki

We consider a supersymmetric extension of the SL(2;Z)-covariant D3-brane action proposed by Nurmagambetov, and prove its kappa-symmetry in an on-shell type-IIB supergravity background.

I. Antoniadis, A. Sagnotti

We review physical motivations and possible realizations of string vacua with large internal volume and/or low string scale and discuss the issue of supersymmetry breaking. In particular, we describe the key features of Scherk-Schwarz deformations in type I models and conclude by reviewing the phenomenon of ``brane supersymmetry breaking'': the tadpo

Andrei P. Kirilyuk

A physically real wave associated with any moving particle and travelling in a surrounding material medium was introduced by Louis de Broglie in a series of short notes in 1923 and in a more complete form in his thesis defended in Paris on the 25th November 1924. This result, recognised by the Nobel Prize in 1929, gave rise to a major direction of "new physi

Raghavan Rangarajan, Supratim Sengupta, Ajit M. Srivastava, ;

We discuss the possibility of generating the baryon asymmetry of the Universe when the temperature of the Universe is much below the electroweak scale. In our model the evaporation of primordial black holes or the decay of massive particles re-heats the surrounding plasma to temperatures above the electroweak transition temperature leading to the restoration

Abel Camacho

In this work we obtain a family of quantum nondemolition variables for the case of a particle moving in an inhomogeneous gravitational field. Afterwards, we calculate the corresponding propagator, and deduce the probabilitites associated with the possible measurements outputs. The comparison, with the case in which the position is being monitored, will allow

Andrew W. Blain, Priyamvada Natarajan

Popular models for the origin of gamma-ray bursts (GRBs) include short-lived massive stars as the progenitors of the fireballs. Hence the redshift distribution of GRBs should track the cosmic star formation rate of massive stars accurately. A significant proportion of high-mass star formation activity appears to occur in regions that are obscured from view i

Gyorgy Szabo, Tibor Antal, Peter Szabo, Michel Droz

The emergence of mutual cooperation is studied in a spatially extended evolutionary prisoner's dilemma game in which the players are located on the sites of cubic lattices for dimensions d=1, 2, and 3. Each player can choose one of the three strategies: cooperation (C), defection (D) or Tit for Tat (T). During the evolutionary process the randomly chosen

Nikolai I. Kochelev, Dong-Pil Min, Yongseok Oh, Vicente Vento

We show that a new Regge trajectory with α_{f_1} (0) \approx 1 and slope α_{f_1}'(0) \approx 0 explains the features of hadron-hadron scattering and photoproduction of the rho and phi mesons at large energy and momentum transfer. This trajectory with quantum numbers P = C = +1 and odd signature can be considered as a natural partner of the Pomeron which

V. Yu. Irkhin, A. V. Zarubin

The Kondo divergences owing to interaction of current carriers with local moments in highly correlated electron systems are considered within the Hubbard and s-d exchange models with infinitely strong on-site interaction, the many-electron Hubbard representation being used. The picture of density of states containing a peak at the Fermi level is obtained. Va

M. F. Bietenholz, N. Bartel, M. P. Rupen

The nucleus of M81 was observed at 8.3 GHz with VLBI at 20 epochs over 4.5yrs, with a linear resolution at the source of about 2000 AU or 0.01 pc. Phase-referenced mapping with respect to the geometric center of supernova 1993J enabled us to find, with a standard error of about 600 AU, a stationary point in the source. We identify this point as the location

W. Tittel, J. Brendel, H. Zbinden, N. Gisin

We present a setup for quantum cryptography based on photon pairs in energy-time Bell states and show its feasability in a laboratory experiment. Our scheme combines the advantages of using photon pairs instead of faint laser pulses and the possibility to preserve energy-time entanglement over long distances. Moreover, using 4-dimensional energy-time states,

Victor Novozhilov, Yuri Novozhilov

We consider use of collective variables for description of composite fields as collective phenomena due to the strong coupling regime. We discuss two approaches, where identification of collective variables of complex quantum system does not depend on knowledge of other degrees of freedom: (a) collective variables as parameters of group transformations chang

Eugene I. Shtyrkov

A new interpretation of cosmological redshifts is proposed to construct the evolved-vacuum model of this phenomenon.The physical vacuum was considered to be a real matter with time-dependent permittivity and permeability. Time variation of these parameters 10^{-10} per year was shown on the base of Maxwell's equations and Hubble's law to obey the exp

A. C. V. Ceapa

In the line of thought of Einstein's 1905 paper on relativity, I get a physical derivation of Lorentz transformation (LT) answering its main criticism and considerably enlarging the area of applications of the theory of relativity.

Ernst Karl Kunst

The rest mass of the hydrogen atom in its ground state is calculated from first physical principles and elementary geometric considerations.

Guennadi A. Kouzaev, Igor V. Nazarov, Andrew V. Kalita

The paper presents new results in the field of super high-speed and multi-valued signal processing. Writting digital information into spatial structures (topological charts) of electromagnetic field pulses allows to use passive circuits for fulfillment several subpicosecond spatial logical operations. This is confirmed by analysis of several physical effects

Andreas Krug, Andreas Buchleitner

We identify a fundamental structure in the spectrum of microwave driven alkali Rydberg states, which highlights the remnants of the Coulomb symmetry in the presence of a non-hydrogenic core. Core-induced corrections with respect to the hydrogen spectrum can be accounted for by a perturbative approach.

Benoit T. Guay

To generate a propulsive force without propellant and external couplings, it has been shown that two confined macroscopic and time-varying charge density waves well separated in space are needed. Here, some physical conditions will be proposed to support and maintain these particular collective modes of charge distributions.

Victor I. Matveev, Olga V. Karpova

We propose the generalization of a known established empirically (Wahl W. and Wucher A. Nucl. Instrum. Meth. B 94, 36(1994)) power law, describing relative mass-spectra of neutral sputtered clusters, on the cases of arbitrary cluster charges. The fluctuation mechanism of charge state formation of sputtering products in the form of large clusters with the num

J. M. Speight, R. S. Ward

A spatially-discrete sine-Gordon system with some novel features is described. There is a topological or Bogomol'nyi lower bound on the energy of a kink, and an explicit static kink which saturates this bound. There is no Peierls potential barrier, and consequently the motion of a kink is simpler, especially at low speeds. At higher speeds, it radiates a

M. Guttormsen, A. Bjerve, M. Hjorth-Jensen, E. Melby

The density of accessible levels at low spin in the (^3He,αγ) reaction has been extracted for the ^{161,162}Dy and ^{171,172}Yb nuclei. The entropy of the even-odd and even-even nuclei has been deduced as a function of excitation energy, and found to reach a maximum of 15 k_B before neutron evaporation. The entropy of one quasi-particle outside an even-even

A. G. Ramm

A method is given for finding small inhomogeneities from surface scattering data. The method consists in localization of the positions and finding the intensities of these small inhomogeneities. The case of acoustic wave scattering is studied, but the method is applicable to electromagnetic waves as well.

A. G. Ramm

It is proved that one cannot approximate stably the first derivative of a smooth function given noisy values of this function and a bound on this function and its first derivative. Such an approximation is shown to be possible if an a priori bound is known for a fractional derivative of order greater than one. An algorithm is proposed for such a stable appro