May 2000 arXiv papers — page 4

Zhen Ye

In a many body system, constituents interact with each other, forming a recursive pattern of interaction and giving rise to many interesting phenomena. Based upon concepts of the modern many body theory, a model for a generic many body system is developed. A novel approach is proposed to investigate the general features in such a system. An interesting phase

A. Malki, J. Alster, G. Asryan, D. Barton

Beams of protons and pions of 5.9 GeV/c were incident on a C target. Neutrons emitted into the back hemisphere, in the laboratory system, were detected in (triple) coincidence with two emerging $p_t>$0.6 GeV/c particles. We present the momentum spectra of the backward going neutrons, which have the same universal shape observed in earlier (inclusive) reactio

Peter Saveliev

For a given pair of maps f,g:X->M from an arbitrary topological space to an n-manifold, the Lefschetz homomorphism is a certain graded homomorphism L:H(X)->H(M) of degree (-n). We prove a Lefschetz-type coincidence theorem: if the Lefschetz homomorphism is nontrivial then there is an x in X such that f(x)=g(x).

A. S. Ustunel, M. Zakai

Suppose that T is a map of the Wiener space into itself, of the following type: T=I+u where u takes its values in the Cameron-Martin space H. Assume also that u is a finite sum of H-valued multiple Ito-Wiener integrals. In this work we prove that if T preserves the Wiener measure, then necessarily u is in the first Wiener chaos and the transformation corresp

Ram Brustein

The quantum theory of near horizon regions of spacetimes with classical spatially flat, homogeneous and isotropic Friedman-Robertson-Walker geometry can be approximately described by a two dimensional conformal field theory. The central charge of this theory and expectation value of its Hamiltonian are both proportional to the horizon area in units of Newton

Kentaro Hori, Amer Iqbal, Cumrun Vafa

We study (2,2) supersymmetric field theories on two-dimensional worldsheet with boundaries. We determine D-branes (boundary conditions and boundary interactions) that preserve half of the bulk supercharges in non-linear sigma models, gauged linear sigma models, and Landau-Ginzburg models. We identify a mechanism for brane creation in LG theories and provide

Shi-Lin Zhu, S. J. Puglia, B. R. Holstein, M. J. Ramsey-Musolf

We construct the complete SU(2) parity-violating (PV) $π, N, Δ$ interaction Lagrangian with one derivative, and calculate the chiral corrections to the PV Yukawa $NNπ$ coupling constant $h_π$ through ${\cal O}(1/Λ_χ^3)$ in the leading order of heavy baryon expansion. We discuss the relationship between the renormalized $\hpi$, the measured value of $\hpi$, a

Alan Kostelecky

This talk summarizes some recent experimental constraints on Lorentz and CPT violation.

Alekhin Sergey

The statistical properties of estimator using covariance matrix for the account of point-to-point correlations due to systematic errors are analyzed. It is shown that the covariance matrix estimator (CME) is consistent for the realistic cases (when systematic errors on the fitted parameters are not extremely large comparing with the statistical ones) and its

Robert D. Klauber

A simple, though rarely considered, thought experiment on relativistic rotation is described in which internal inconsistencies in the theory of relativity seem to arise. These apparent inconsistencies are resolved by appropriate insight into the nature, and unique properties, of the non-time-orthogonal rotating frame. The analysis also explains a heretofore

R. Winkler, S. J. Papadakis, E. P. De Poortere, M. Shayegan

Coupling the spin degree of freedom to the anisotropic orbital motion of two-dimensional (2D) hole systems gives rise to a highly anisotropic Zeeman splitting with respect to different orientations of an in-plane magnetic field B relative to the crystal axes. This mechanism has no analogue in the bulk band structure. We obtain good, qualitative agreement bet

W. A. Atkinson, P. J. Hirschfeld, A. H. MacDonald, K. Ziegler

We demonstrate that discrepancies between predicted low-energy quasiparticle properties in disordered 2D d-wave superconductors occur because of the unanticipated importance of disorder model details and normal-state particle-hole symmetry. This conclusion follows from numerically exact evaluations of the quasiparticle density-of-states predicted by the Bogo

Y. F. Huang, Z. G. Dai, T. Lu

Due to some refinements in the dynamics, we can follow the overall evolution of a realistic jet numerically till its bulk velocity being as small as $βc \sim 10^{-3} c$. We find no obvious break in the optical light curve during the relativistic phase itself. However, an obvious break does exist at the transition from the relativistic phase to the non-relati

V. E. Zavlin, G. G. Pavlov, D. Sanwal, J. Truemper

The central source of the supernova remnant PKS 1209-52 was observed with the Advanced CCD Imaging Spectrometer aboard Chandra X-ray observatory on 2000 January 6-7. The use of the Continuos Clocking mode allowed us to perform the timing analysis of the data with time resolution of 2.85 ms and to find a period P=0.42412927+/-2.3e-7 s. The detection of this s

Sergei V. Ketov

New non-abelian supersymmetric generalizations of the four-dimensional Born-Infeld action are constructed in N=1 and N=2 superspace, to all orders in the gauge superfield strength. The proposed actions are dictated by simple (manifestly supersymmetric and gauge-covariant) non-linear constraints.

Yuval Grossman, Howard E. Haber

In R-parity-violating supersymmetric models (with a conserved baryon number), there are no quantum numbers that distinguish the lepton-doublet and down-type Higgs supermultiplets. As a result, the R-parity-violating parameters depend on the basis choice for these superfields, although physical observables are independent of the choice of basis. This paper pr

A. K. Popov

An influence of nonlinear interference processes at quantum transitions under strong resonance electromagnetic fields on absorption, amplification and refractive indices as well as on four-wave mixing processes is investigated. Doppler broadening of the coupled transitions, incoherent excitation, relaxation processes, as well as power saturation processes as

Peter Ozsvath, Zoltan Szabo

In this paper, we derive new adjunction inequalities for embedded surfaces with non-negative self-intersection number in four-manifolds. These formulas are proved by using relations between Seiberg-Witten invariants which are induced from embedded surfaces. To prove these relations, we develop the relevant parts of a Floer theory for four-manifolds which bou

James Allen Fill, Motoya Machida

We explore and relate two notions of monotonicity, stochastic and realizable, for a system of probability measures on a common finite partially ordered set (poset) S when the measures are indexed by another poset A. We give counterexamples to show that the two notions are not always equivalent, but for various large classes of S we also present conditions on

Johan Kustermans

We introduce the construction of induced corepresentations in the setting of locally compact quantum groups and prove that the resulting induced corepresentations are unitary under some mild integrability condition. We also establish a quantum analogue of the classical bijective correspondence between quasi-invariant measures and certain measures on the larg

Kurt Just, Zbigniew Oziewicz, Erwin Sucipto

We deal with quantum field theory in the restriction to external Bose fields. Let $(iγ^μ\partial_μ- \mathcal{B})ψ=0$ be the Dirac equation. We prove that a non-quantized Bose field $\mathcal{B}$ is a functional of the Dirac field $ψ$, whenever this $ψ$ is strictly canonical. Performing the trivial verification for the $\mathcal{B} := m = $ constant which yie

Kurt Just, Kam-Yuen Kwong, Zbigniew Oziewicz

Participants of this workshop pursue the old Neutrino Theory of Light vigorously. Other physicists have long ago abandoned it, because it lacks gauge invariance. In the recent Quantum Induction (QI), all basic Bose fields ${\mathcal B}^{P}$ are local limits of quantum fields composed of Dirac's $Ψ$ (for leptons and quarks). The induced field equations of

T. Kopf

Spacetime, understood as a globally hyperbolic manifold, may be characterized by spectral data using a 3+1 splitting into space and time, a description of space by spectral triples and by employing causal relationships, as proposed earlier. Here, it is proposed to use the Hadamard condition of quantum field theory as a smoothness principle.

Victor T. Kim, Grigorii B. Pivovarov, James P. Vary

Scaling violation of inclusive jet production at small-$x$ in hadron scattering with increasing total collision energy is discussed. Perturbative QCD based on the factorisation theorem for hard processes and GLAPD evolution equations predicts a minimum for scaled cross-section ratio that depends on jet rapidity. Studies of such a scaling violation can reveal

Matthias Burkardt, Nikolai Uraltsev

We present a number of exact relations for the heavy quark limit and develop an analytical 1/m_Q expansion for heavy mesons in the 't Hooft model. Among the new results are relation 3μ_π^2=\barΛ^2 - m_{sp}^2+β^2, 1/m_Q corrections to the decay constants, to the kinetic expectation values and 1/m_Q^2 nonperturbative corrections to the B->D amplitude at ze

P. Ciafaloni

Hard processes at the TeV scale exhibit enhanced (double log) EW corrections, that need resummation in view of the high level of precision of Next Linear Colliders. The fact that the weak sector is spontaneously broken causes some peculiarities with respect to unbroken theories like QCD. For observables that are exclusive with respect to $W,Z$ emission, some

Dimitrios Skraparlis

This paper proposes a method for identification of a user`s fixed string set (which can be a command/instruction set for a terminal or microprocessor). This method is fast and has very small memory requirements, compared to a traditional full string storage and compare method. The user feeds characters into a microcontroller via a keyboard or another micropr

S. H. Pan, E. W. Hudson, A. K. Gupta, K-W Ng

We report on low temperature scanning tunneling microscopy (STM) studies of the electronic structure of vortex cores in Bi2Sr2CaCu2O8+d (BSCCO). At the vortex core center, an enhanced density-of-states (DOS) is observed at energies near 7 meV. Spectroscopic imaging at these energies reveals an exponential decay of these 'core states' with a decay len

Johann Kroha, Peter Wölfle

We review a recently developed method, based on a pseudoparticle representation of correlated electrons, to describe both Fermi liquid and non-Fermi liquid behavior in quantum impurity systems. The role of the projection onto the physical Hilbert space and the impossibility of slave boson condensation are discussed. By summing the leading coherent spin and c

Ryo Maezono, Naoto Nagaosa

The $e_g$-orbital states with complex coefficients of the linear combination of $x^2-y^2$ and $3z^2-r^2$ are studied for the ferromagnetic state in doped manganites. Especially the focus is put on the competition among uniform complex, staggered complex, and real orbital states. As the hole-doping $x$ increases, the real, the canted complex, and the staggere

K. Belczynski, J. Mikolajewska, U. Munari, R. J. Ivison

We present a new catalogue of symbiotic stars. In our list we include 188 symbiotic stars as well as 28 objects suspected of being symbiotic. For each star, we present basic observational material: coordinates, V and K magnitudes, ultraviolet (UV), infrared (IR), X-ray and radio observations. We also list the spectral type of the cool component, the maximum

Vladimir A. Lefebvre, Yuri N. Efremov

The paper is devoted to a new direction in SETI. After a general discussion of the field, the authors put forth the hypothesis that the black holes may serve as a physical substratum for intelligent beings. This hypothesis is based on four parallels between the brain-psyche system, on the one hand, and black holes, on the other. (1) The descriptions of brain

Thomas Papenbrock, George F. Bertsch

We study the spectrum of rotating Bose-Einstein Condensates in the limit of weak repulsive interactions and present analytical and numerical results for energies and wave functions. While the low-lying states are of collective nature, the high-lying states are dominated by single-particle excitations and can accurately approximated by simple polynomial expre

D. Orgad, S. A. Kivelson, E. W. Carlson, V. J. Emery

In the normal state of the high temperature superconductors Bi_2Sr_2CaCu_2O_{8+delta} and La_{2-x}Sr_{x}CuO_4, and in the related ``stripe ordered'' material La_1.25Nd_0.6Sr_0.15CuO_4, there is sharp structure in the measured single hole spectral function A(k,w) considered as a function of k at fixed small binding energy w. At the same time, as a fun

Warren R. Brown, Scott J. Kenyon, Margaret J. Geller, Daniel G. Fabricant

We discuss V and R band photometry for 67% of the Sullivan et al. 2000 SA57 ultraviolet-selected galaxy sample. In a sample of 176 UV-selected galaxies, Sullivan et al. 2000 find that 24% have (UV-B) colors too blue for consistency with starburst spectral synthesis models. We propose that these extreme blue, UV excess galaxies are Wolf-Rayet (WR) galaxies, s

T. -S. H. Lee, R. B. Wiringa

We show that the neutron and proton transition densities predicted by recent quantum Monte Carlo calculations for A=6,7 nuclei are consistent with pion scattering from 6Li and 7Li at energies near the Delta resonance. This has provided a microscopic understanding of the enhancement factors for quadrople excitations, which were needed to describe pion inelast

V. V. Nesterenko, G. Lambiase, G. Scarpetta

The Casimir energy of a semi-circular cylindrical shell is calculated by making use of the zeta function technique. This shell is obtained by crossing an infinite circular cylindrical shell by a plane passing through the symmetry axes of the cylinder and by considering only a half of this configuration. All the surfaces, including the cutting plane, are assu

Paolo Catelan, Cristiano Porciani, Marc Kamionkowski

We calculate the galaxy bispectrum in both real and redshift space adopting the most common prescriptions for local Eulerian biasing and Lagrangian evolving-bias model. We show that the two biasing schemes make measurably different predictions for these clustering statistics. The Eulerian prescription implies that the galaxy distribution depends only on the

A. Derevianko

Contributions from the Breit interaction in atomic-structure calculations account for 1.3sigma of the previously reported 2.5sigma deviation from the Standard Model in the 133Cs weak charge [S.C. Bennett and C.E. Wieman, Phys. Rev. Lett. 82, 2484 (1999)]. The updated corrections for the neutron distribution reduce the discrepancy further to 1.0sigma. The upd

Carlo Baccigalupi, Sabino Matarrese, Francesca Perrotta

We study the cosmological role of a Tracking Field $ϕ$ in Extended Quintessence scenarios (TEQ), where the dynamical vacuum energy driving the acceleration of the universe today is coupled with the Ricci scalar, $R$, with a term of the form $F(ϕ)R/2$, where $F(ϕ) = 1/8πG+ξ(ϕ^{2}-ϕ_{0}^{2})$. Tracker solutions for these NMC models, with inverse power-law pote

T. P. O'Brien, D. Sornette, R. L. McPherron

We introduce the Statistical Asynchronous Regression (SAR) method: a technique for determining a relationship between two time varying quantities without simultaneous measurements of both quantities. We require that there is a time invariant, monotonic function Y = u(X) relating the two quantities, Y and X. In order to determine u(X), we only need to know th

PACS Collaboration, T. Manke, A. Ali Khan, S. Aoki

We study the effects of two dynamical sea quarks on the spectrum of heavy quarkonia. Within the non-relativistic approach to Lattice QCD we found sizeable changes to the hyperfine splitting, but we could not observe any changes for the fine structure. We also investigated the scaling behaviour of our results for several different lattice spacings.

D. P. DiVincenzo, D. Bacon, J. Kempe, G. Burkard

Experimental implementations of quantum computer architectures are now being investigated in many different physical settings. The full set of requirements that must be met to make quantum computing a reality in the laboratory [1] is daunting, involving capabilities well beyond the present state of the art. In this report we develop a significant simplificat

Jerome Martin, Dominik J. Schwarz

From a general ansatz for the effective potential of cosmological perturbations we find new, exact solutions in single-scalar-field inflation: a three parameter family of exact inflationary solutions that encompasses all exact solutions that have been known previously (power-law inflation, Easther's model, and a generalised version of Starobinsky's s

Marc G. Zacher, Robert Eder, Enrico Arrigoni, Werner Hanke

Recent photoemission (ARPES) experiments on cuprate superconductors provide important guidelines for a theory of electronic excitations in the stripe phase. Using a cluster perturbation theory, where short-distance effects are accounted for by exact cluster diagonalization and long-distance effects by perturbation (in the hopping), we calculate the single-pa

A. Del Fabbro, D. Treleani

The scale factor $σ_{eff}$, which characterizes double parton collisions in high energy hadron interactions, is a direct manifestation of the distribution of the interacting partons in transverse space, in such a way that different distributions give rise to different values of $σ_{eff}$ in different double parton collision processes. We work out the value o

P. Calabrese, M. Caselle, A. Celi, A. Pelissetto

We discuss the analytic properties of the Callan-Symanzik beta-function beta(g) associated with the zero-momentum four-point coupling g in the two-dimensional phi^4 model with O(N) symmetry. Using renormalization-group arguments, we derive the asymptotic behavior of beta(g) at the fixed point g^*. We argue that beta'(g) = beta'(g^*) + O(|g-g^*|^{1/7}

W. Dür, G. Vidal, J. I. Cirac

Invertible local transformations of a multipartite system are used to define equivalence classes in the set of entangled states. This classification concerns the entanglement properties of a single copy of the state. Accordingly, we say that two states have the same kind of entanglement if both of them can be obtained from the other by means of local operati

G. J. Gounaris, J. Layssac, F. M. Renard

We establish the general off-shell structure of the three neutral gauge boson self-couplings V1*V2*V3*, with applications to the Z*Z*Z*, Z*Z*gamma*, gamma*gamma*Z* cases. New coupling forms appear which do not exist when two gauge bosons are on-shell. We give the contribution arising from a fermionic triangle loop. It covers both the standard model (SM) and

Daniel M. Zuckerman, Thomas B. Woolf

Exploiting stochastic path integral theory, we obtain \emph{by simulation} substantial gains in efficiency for the computation of reaction rates in one-dimensional, bistable, overdamped stochastic systems. Using a well-defined measure of efficiency, we compare implementations of ``Dynamic Importance Sampling'' (DIMS) methods to unbiased simulation. T

Nigel D Marsh, Henrik Svensmark

The influence of solar variability on climate is currently uncertain. Recent observations have indicated a possible mechanism via the influence of solar modulated cosmic rays on global cloud cover. Surprisingly the influence of solar variability is strongest in low clouds (<= 3km), which points to a microphysical mechanism involving aerosol formation that is

Dongsu Bak, Sung Ku Kim, Kwang-Sup Soh, Jae Hyung Yee

We consider the nonrelativistic field theory with a quartic interaction on a noncommutative plane. We compute the four point scattering amplitude within perturbative analysis to all orders and identify the beta function and the running of the coupling constant. Since the theory admits an equivalent description via the N particle Schrodinger equation, we rega

W. Rodejohann, K. Zuber

The graph of neutrinoless double beta decay is applied to HERA and generalized to final states with any two charged leptons. Considered is the case in which one of the two escapes typical identification criteria and the case when a produced tau decays hadronically. Both possibilities give one isolated lepton with high transverse momentum, hadronic activity a

S. G. Rubin, M. Yu. Khlopov, A. S. Sakharov

The collapse of sufficiently large closed domain wall produced during second order phase transition in the vacuum state of a scalar field can lead to the formation of black hole. The origin of domain walls with appropriate size and energy density could be a result of evolution of an effectively massless scalar field at the inflational epoch. We demonstrate t

Holger Gies

The effective action for the Polyakov loop serving as an order parameter for deconfinement is obtained in one-loop approximation to second order in a derivative expansion. The calculation is performed in $d\geq 4$ dimensions, mostly referring to the gauge group SU(2). The resulting effective action is only capable of describing a deconfinement phase transiti

Michael Faux, Dieter Lust, Burt A. Ovrut

In this paper we consider orbifold compactifications of M-theory on $S^1/{\bf Z}_2\times T^4/{\bf Z}_2$. We discuss solutions of the local anomaly matching conditions by twisted vector, tensor and hypermultiplets confined on the local orbifold six-planes. In addition we consider phase-transitions among different solutions which are mediated by M-theory fiveb

R. Seviour, A. F. Volkov

We considered a mesoscopic superconductor/normal metal (S/N) structure in which the N reservoirs are maintained at different temperatures. It is shown that in the absence of current between the N reservoirs a voltage difference $V_{T}$ arises between the superconducting and normal conductors. The voltage $V_{T}$ oscillates with increasing phase difference $ϕ

Takahiro Miura, Tetsuo Shindou, Eiichi Takasugi, Masaki Yoshimura

In our previous paper, we proposed the democratic-type neutrino mass matrix which gives interesting predictions, $θ_{23}=-\fracπ4$, $|\tan θ_{12}|=\sqrt{2-3\sin^2 θ_{13}}$ and $δ=\frac π2$, where $θ_{ij}$ is the mixing angle between mass eigenstates $ν_i$ and $ν_j$, and $δ$ is the CP violation angle in the standard parameterization of mixing matrix. In this

Dosang Joe

It is well known that the twisters, section of twister space, classify the almost complex structure on even dimensional Riemannian manifold $X$. In this paper, it will be proved that a harmonic and anti-holomorphic twister is equivalent ti a symplectic structure on $X$.

N. Kida, M. Hangyo, M. Tonouchi

Direct experimental estimations of the low-energy ($1.5\sim10$ meV) complex dielectric constants spectrum and its temperature variation have been investigated for La$_{0.7}$Ca$_{0.3}$MnO$_3$ thin films using terahertz time-domain spectroscopy. At low temperatures, a clear Drude-term emerges. With increasing temperature, the scattering rate increases, while t

Tatsuo Kobayashi, Haruhiko Terao

We examine the (softly broken) supersymmetric gauge-Higgs-Yukawa theories satisfying the compositeness conditions at a certain scale. In these theories the Higgs superfields can be regarded as the chiral composite fields. It is found that there are the fundamental theories, which contain the dimension 5 interactions and the hard SUSY breaking in perturbation

J. C. Niemeyer

The implementation of a Planck-scale high frequency and short wavelength cutoff in quantum theories on expanding backgrounds may have potentially nontrivial implications, such as the breaking of local Lorentz invariance and the existence of a yet unknown mechanism for the creation of vacuum modes. In scenarios where inflation begins close to the cutoff scale

A. K. Popov, S. G. Rautian

Interference effects in quantum transitions, giving rise to amplification without inversion, optical transparency and to enhancements in nonlinear optical frequency conversions are considered. Review of the relevant early theoretical and experimental results is given. The role of relaxation processes, spontaneous cascade of polarizations, local field effects

V. I. Yukalov

Interplay between the effects of coherent radiation and localization of light is analysed. A system of two-level atoms is placed in a medium interacting with electromagnetic field. The matter-light interaction can result in the appearance of a band gap in the spectrum of polariton states. If an atom with a resonance frequency inside the gap is incorporated i

M. Lewenstein, B. Kraus, P. Horodecki, J. I. Cirac

We provide a canonical form of mixed states in bipartite quantum systems in terms of a convex combination of a separable state and a, so-called, edge state. We construct entanglement witnesses for all edge states. We present a canonical form of nondecomposable entanglement witnesses and the corresponding positive maps. We provide constructive methods for the

G. M. D&#39;Ariano, L. Maccone, M. G. A. Paris

Quantum estimation of the operators of a system is investigated by analyzing its Liouville space of operators. In this way it is possible to easily derive some general characterization for the sets of observables (i.e. the possible quorums) that are measured for the quantum estimation. In particular we analyze the reconstruction of operators of spin systems.

Ulrich Mohrhoff

The problem of understanding quantum mechanics is in large measure the problem of finding appropriate ways of thinking about the spatial and temporal aspects of the physical world. The standard, substantival, set-theoretic conception of space is inconsistent with quantum mechanics, and so is the doctrine of local realism, the principle of local causality, an

K. Arun Kumar, Michael D. Graham

Starting from stationary bifurcations in Couette-Dean flow, we compute nontrivial stationary solutions in inertialess viscoelastic circular Couette flow. These solutions are strongly localized vortex pairs, exist at arbitrarily large wavelengths, and show hysteresis in the Weissenberg number, similar to experimentally observed ``diwhirl&#39;&#39; patterns. B

Christoph Adami, Charles Ofria, Travis C. Collier

In order to make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolu

V. P. Aleshin, M. Centelles, X. Viñas, N. G. Nicolis

We show that the quasifission paths predicted by the one-body dissipation dynamics, in the slowest phase of a binary reaction, follow a quasistatic path, which represents a sequence of states of thermal equilibrium at a fixed value of the deformation coordinate. This establishes the use of the statistical particle-evaporation model in the case of dynamical t

M. C. Lai, K. H. Chiam, M. C. Cross, H. S. Greenside

Buoyancy-induced (Rayleigh-Benard) convection of a fluid between two horizontal plates is a central paradigm for studying the transition to complex spatiotemporal dynamics in sustained nonequilibrium systems. To improve the analysis of experimental data and the quantitative comparison of theory with experiment, we have developed a three-dimensional finite-di

G. Baez, F. Leyvraz, R. A. Mendez-Sanchez, T. H. Seligman

We present a finite element algorithm that computes eigenvalues and eigenfunctions of the Laplace operator for two-dimensional problems with homogeneous Neumann or Dirichlet boundary conditions or combinations of either for different parts of the boundary. In order to solve the generalized eigenvalue problem, we use an inverse power plus Gauss-Seidel algorit

A. R. Champneys, B. A. Malomed, J. Yang, D. J. Kaup

It is commonly held that a necessary condition for the existence of solitons in nonlinear-wave systems is that the soliton&#39;s frequency (spatial or temporal) must not fall into the continuous spectrum of radiation modes. However, this is not always true. We present a new class of {\it % codimension-one} solitons (i.e., those existing at isolated frequency

Andrey A. Sukhorukov, Tristram J. Alexander, Yuri S. Kivshar, Solomon M. Saltiel

We apply the concept of multistep cascading to the problem of fourth-harmonic generation in a single quadratic crystal. We analyze a new model of parametric wave mixing and describe its stationary solutions for two- and three-color plane waves and spatial solitons. Some applications to the optical frequency division as well as the realization of the double-p

Yuri B. Suris

We prove the integrability of the discretization of the Neumann system recently proposed by V. Adler.

Rui Carvalho, Bastien Fernandez, R. Vilela Mendes

The phenomenology of a system of two coupled quadratic maps is studied both analytically and numerically. Conditions for synchronization are given and the bifurcations of periodic orbits from this regime are identified. In addition, we show that an arbitrarily large number of distinct stable periodic orbits may be obtained when the maps parameter is at the F

Seong-Ok Jeong, Hie-Tae Moon, Tae-Wook Ko

We studied the effect of nearest pattern interaction on a globally pattern formation in a 2-dimensional space, where patterns are to grow initially from a noise in the presence of periodic supply of energy. Although our approach is general, we found that this study is relevant in particular to the pattern formation on a periodically vibrated granular layer,

Alexander Dynin

Functional Schrödinger equations for interacting fields are solved via rigorous non-perturbative Feynman type integrals.

Serge Maumary, Izumi Ojima

The homotopical information hidden in a supersymmetric structure is revealed by considering deformations of a configuration manifold. This is in sharp contrast to the usual standpoints such as Connes&#39; programme where a geometrical structure is rigidly fixed. For instance, we can relate supersymmetries of types N=2n and N=(n, n) in spite of their gap due

G. S. Djordjevic, B. Dragovich

The Feynman path integral in p-adic quantum mechanics is considered. The probability amplitude ${\cal K}_p (x^{\prime\prime},t^{\prime\prime}; x^\prime,t^\prime)$ for one-dimensional systems with quadratic actions is calculated in an exact form, which is the same as that in ordinary quantum mechanics.

Goran S. Djordjevic, Branko Dragovich

p-Adic generalization of the Feynman path integrals in quantum mechanics is considered. The probability amplitude for a particle in a constant field is calculated. Path integrals over p-adic space have the same form as those over R.

Ken Ito

We classify all total orders having a certain convex property on the positive root system of an arbitrary untwisted affine Lie algebra ${\frak g}$. Such total orders are called convex orders and are used to construct convex bases of Poincaré-Birkhoff-Witt type of the upper triangular subalgebra $U_q^+$ of the quantized enveloping algebra $U_q({\frak g})$.

Gerald Höhn

We introduce self-dual codes over the Kleinian four group $K = \mathbb{Z}_2 \times \mathbb{Z}_2$ for a natural quadratic form on $K^n$ and develop the theory. Topics studied are: weight enumerators, mass formulas, classification up to length 8, neighbourhood graphs, extremal codes, shadows, generalized t-designs, lexicographic codes, the Hexacode and its odd

Yves Colin de Verdiere, San Vu Ngoc

In this paper, we describe Bohr-Sommerfeld rules for semi-classical completely integrable systems with 2 degrees of freedom with non degenerate singularities (Morse-Bott singularities) under the assumption that the energy level of the first Hamiltonian is non singular. The more singular case of {\it focus-focus} singularities is studied in [Vu Ngoc San, CPAM

Alexander Barvinok, Alex Samorodnitsky

We develop general methods to obtain fast (polynomial time) estimates of the cardinality of a combinatorially defined set via solving some randomly generated optimization problems on the set. Geometrically, we estimate the cardinality of a subset of the Boolean cube via the average distance from a point in the cube to the subset. As an application, we presen

Stefaan Vaes

In this paper we study actions of locally compact quantum groups on von Neumann algebras and prove that every action has a canonical unitary implementation, paralleling Haagerup&#39;s classical result on the unitary implementation of a locally compact group action. This result is an important tool in the study of quantum groups in action. We will use it in t

Winfried Bruns, Aldo Conca

The first sections contain a survey of the application of the Knuth-Robinson-Schensted corerspondence to the computation of Groebner bases of determinantal ideals. We also set up a conceptual framework for this application in terms of so-called &#34;KRS invariants&#34;. Then we show that the initial ideal of a determinantal ideal &#34;defined by shape&#34; i

Martin Markl

We explain the essence of perturbation problems. The key to understanding is the structure of chain homotopy equivalence -- the standard one must be replaced by a finer notion which we call a strong chain homotopy equivalence. We prove an Ideal Perturbation Lemma and show how both new and classical results follow from this ideal statement.

I. K. Kostov, I. Krichever, M. Mineev-Weinstein, P. Wiegmann

We review the concept of $τ$-function for simple analytic curves. The $τ$-function gives a formal solution to the 2D inverse potential problem and appears as the $τ$-function of the integrable hierarchy which describes conformal maps of simply-connected domains bounded by analytic curves to the unit disk. The $τ$-function also emerges in the context of topol

L. C. de Albuquerque, M. Gomes, A. J. da Silva

We apply a soft version of the BPHZ subtraction scheme to the computation of two-loop corrections from an Abelian Chern-Simons field coupled to (massive) scalar matter with a $λ(Φ^\dagΦ)^2$ and $ν(Φ^\dagΦ)^3$ self-interactions. The two-loop renormalization group functions are calculated. We compare our results with those in the literature.

R. Manvelyan, A. C. Petkou

We study the trace anomaly of the (2,0) tensor multiplet in d=6 in the presence of a background SO(5) vector field acting as a source for the R-current. Using both a free-field theory calculation and AdS_7/CFT_6 correspondence, we find that only one of the two possible anomaly structures is non-zero and that its coefficient at strong-coupling differs by the

F. Jegerlehner

The increasing precision of many experiments in elementary particle physics leads to continuing interest in perturbative higher order calculations in the electroweak Standard Model or extensions of it. Such calculations are of increasing complexity because more loops and/or more legs are considered. Correspondingly efficient computational methods are mandato

J. Zinn-Justin

In these notes we review some properties of Statistical Quantum Field Theory at equilibrium, i.e Quantum Field Theory at finite temperature. We explain the relation between finite temperature quantum field theory in (d,1) dimensions and statistical classical field theory in d+1 dimensions. This identification allows to analyze the finite temperature QFT in t

H. V. Klapdor-Kleingrothaus, St. Kolb, U. Sarkar

If the neutrino is Majorana type and the electroweak phase transition is second or weak first order, neutrino-induced interactions together with sphaleron transitions have the potential to erase a previously generated baryon asymmetry of the universe. Taking correctly into account the evolution of the vacuum expectation of the Higgs field the effective light

Somasundaram Arunagiri, Hitoshi Yamamoto

We study the inclusive charmless semileptonic decay of $Λ_b$, $Λ_b \to X_u l ν_l$, in the framework of heavy quark expansion and find that the rate is substantially enhanced by spectator effect. We obtain $Br(b \to X_u l ν_l)$ to be $1.13 \times 10^{-3}$ for $|V_{ub}| = 3.3 \times 10^{-3}$. We discuss our result in light of the recent LEP measurements of the

Balint Joo, Brian Pendleton, Anthony D. Kennedy, Alan C. Irving

We investigate instability and reversibility within Hybrid Monte Carlo simulations using a non-perturbatively improved Wilson action. We demonstrate the onset of instability as tolerance parameters and molecular dynamics step sizes are varied. We compare these findings with theoretical expectations and present limits on simulation parameters within which a s

F. Knechtli, R. Sommer

We study the potential of a static quark anti-quark pair in the confinement ``phase&#39;&#39; of the SU(2) Higgs model. Around separation r_b, the confining string of the gauge field breaks by formation of a dynamical pair of light quarks. The ground state and first excited state static potentials are determined by a variational technique from a matrix corre

G. Giacomelli, M. Giorgini, T. Lari, M. Ouchrif

We present a bibliography compilation on magnetic monopoles updated to include references till the end of year 1999. It is intended to contain nearly all the experimental papers on the subject and only the theoretical papers which have some specific experimental implications.

O. Biebel

Determinations of the strong coupling constant alpha_S at centre-of-mass energies of 192 through 202 GeV at LEP are presented. The energy evolution of alpha_S is in agreement with the prediction of QCD. The combined investigation of OPAL and JADE data in the energy range of 35 through 189 GeV yields alpha_S(m_Z)=0.1187^{+0.0034}_{-0.0019}. The strenght of th

R. O. Avakian, K. A. Ispirian, R. K. Ispirian, V. G. Khachatryan

For the high energy electromagnetic showers the thickness dependence of a) the development of electron and positron components, b) the difference between the secondary electron and positron numbers, c) the charge asymmetry of high energy electromagnetic showers, as well as d) the spectral distributions of the components at the shower maxima for various energ