November 2000 arXiv papers — page 7

Simon Davis

A rationality condition is derived for the existence of odd perfect numbers involving the square root of a product, which consists of a sequence of repunits, multiplied by twice the base of one of the repunits. This constraint also provides an upper bound for density of odd integers which could satisfy ${{σ(N)}\over N}=2$, where $N$ belongs to a fixed interv

Jorge Vitorio Pereira

We investigate the interplay between invariant varieties of vector fields and the inflection locus of linear systems with respect to the vector field. Among the consequences of such investigation we obtain a computational criteria for the existence of rational first integrals of a given degree, bounds for the number of first integrals on families of vector f

Bruno Martelli, Carlo Petronio

We describe an algorithm which has enabled us to give a complete list, without repetitions, of all closed oriented irreducible 3-manifolds of complexity up to 9. More interestingly, we have actually been able to give a "name" to each such manifold, by recognizing its canonical decomposition into Seifert fibred spaces and hyperbolic manifolds. The alg

Joseph A. Minahan, Barton Zwiebach

In this paper we incorporate gauge fields into the tachyon field theory models for unstable D-branes in bosonic and in Type II string theories. The chosen couplings yield massless gauge fields and an infinite set of equally spaced massive gauge fields on codimension one branes. A lack of a continuum spectrum is taken as evidence that the stable tachyon vacuu

S. I. Vacaru, I. A. Chiosa, Nadejda A. Vicol

We outline the the geometry of locally anisotropic (la) superspaces and la-supergravity. The approach is backgrounded on the method of anholonomic superframes with associated nonlinear connection structure. Following the formalism of enveloping algebras and star product calculus we propose a model of gauge la-gravity on noncommutative spaces. The correspondi

J. A. Castro Pena, G. Parente, E. Zas

Using a recent parametrization of nuclear effects in parton distribution functions we calculate the neutrino-nucleon cross section at energies relevant for ultra high energy neutrino telescopes. The modification of the cross section in comparison with the calculation using parton densities in free nucleons is of the order of few per cent for the parameter ra

P. Peter, C. Ringeval

The equation of state for a superconducting cosmic string whose current is due to fermionic zero modes is derived analytically in the case where the back-reaction of the fermions to the background is neglected. It is first shown that the zero mode fermions follow a zero temperature distribution because of their interactions (or lack thereof) with the string-

E. Lisi, A. Marrone, D. Montanino, A. Palazzo

We propose a simple prescription to calculate the solar neutrino survival probability P_{ee} in the quasivacuum oscillation (QVO) regime. Such prescription is obtained by matching perturbative and exact analytical results, which effectively take into account the density distribution in the Sun as provided by the standard solar model. The resulting analytical

Z. Was

The status of the Monte Carlo programs for the simulation of the $τ$ lepton production in high energy accelerator experiments and decay is reviewed. In particular, the status of the following packages is discussed: (i) TAUOLA for tau-lepton decay, (ii) PHOTOS for radiative corrections in decays, (iii) KORALB, KORALZ, KKMC packages for tau-pair production in

J. Portoles

Until present the study of the form factors associated to the vector and axial-vector components of the hadronic weak current has been carried out with a plethora of modelizations of the underlying strong interactions. While of importance to get an understanding of the dynamics involved, the amount and quality of the experimental data start to show some disc

O. Benhar, S. Fantoni, G. I. Lykasov

The $n$-th moments of the nuclear structure function $F_2^A(x,Q^2)$ are analyzed using the off-shell kinematics appropriate to describe deep inelastic electron-nucleus scattering within the impulse approximation. It is shown that off-shell effects are sensitive to the form of both the nuclear spectral function and the nucleon structure function $F_2^N(x,Q^2)

Sandor Hegyi

KNO scaling, i.e. the collapse of multiplicity distributions P_n onto a universal scaling curve manifests when P_n is expressed as the distribution of the standardized multiplicity (n-c)/lambda with c and lambda being location and scale parameters governed by leading particle effects and the growth of average multiplicity. At very high energies, strong viola

M. Gluck, A. Hartl, E. Reya

The possibilities to determine the flavor structure of the polarized sea (antiquark) distributions of the nucleon via vector boson $(γ^*, W^{\pm}, Z^0)$ production at high energy polarized hadron--hadron colliders, such as the Relativistic Heavy--Ion Collider (RHIC), are studied in detail. In particular the perturbative stability of the expected asymmetries

N Study Group, M. Anselmino, E. C. Aschenauer, S. Belostotski

Measurements of polarized electron-nucleon scattering can be realized at the TESLA linear collider facility with projected luminosities that are about two orders of magnitude higher than those expected of other experiments at comparable energies. Longitudinally polarized electrons, accelerated as a small fraction of the total current in the e+ arm of TESLA,

R. Vogt

Sea quark distributions in the nucleon have naively been expected to be generated perturbatively by gluon splitting. In this case, there is no reason for the light quark and anti-quark sea distributions to be different. No asymmetries in the strange or heavy quark sea distributions are predicted in the improved parton model. However, recent experiments have

Xiao-Jun Wang, Mu-Lin Yan

We study chiral expansion at $m_ρ$-scale in framework of chiral constituent quark model. The lowest vector meson resonsances are treated as composited fields of constituent quarks. We illustrate that, at energy scale of $ρ$-meson mass, the chiral expansion expansion converges slowly. Therefore, it is possible to construct a well-defined chiral effective fiel

V. K. Shchigolev, M. V. Shchigolev

The exact solutions of Einstein - Yang - Mills and interacting with SO (3) - Yang-Mills field nonlinear scalar field equations in a class of spatially homogeneous cosmological Friedmann models are obtained.

V. C. de Andrade, L. C. T. Guillen, J. G. Pereira

The fundamentals of the teleparallel equivalent of general relativity are presented, and its main properties described. In particular, the field equations, the definition of an energy--momentum density for the gravitational field, the teleparallel version of the equivalence principle, and the dynamical role played by torsion as compared to the corresponding

Sanjeev V. Dhurandhar, Alberto Vecchio

We consider the problem of searching for continuous gravitational wave sources orbiting a companion object. This issue is of particular interest because the LMXB's, and among them Sco X-1, might be marginally detectable with 2 years coherent observation time by the Earth-based laser interferometers expected to come on line by 2002, and clearly observable by

Rens Bod

We aim at finding the minimal set of fragments which achieves maximal parse accuracy in Data Oriented Parsing. Experiments with the Penn Wall Street Journal treebank show that counts of almost arbitrary fragments within parse trees are important, leading to improved parse accuracy over previous models tested on this treebank. We isolate a number of dependenc

Velimir Bardek, Stjepan Meljanac

We consider a model of N two-dimensional bosons in a harmonic trap with translational and rotational invariant, weak two-particle interaction. We present in configuration space a systematical recursive method for constructing all wave functions with angular momentum L and corresponding energies and apply it to L\leq 6 for all N. The lower and the upper bound

A. Erbe, C. Weiss, W. Zwerger, R. H. Blick

We observe transport of electrons through a metallic island on the tip of a nanomechanical pendulum. The resulting tunneling current shows distinct features corresponding to the discrete mechanical eigenfrequencies of the pendulum. We report on measurements covering the temperature range from 300 K down to 4.2 K. We explain the I-V curve, which differs from

V. A. Krupenin, A. B. Zorin, D. E. Presnov, M. N. Savvateev

We report on a new type of single-electron transistor (SET) comprising two highly resistive Cr thin-film strips (~ 1um long) connecting a 1 um-long Al island to two Al outer electrodes. These resistors replace small-area oxide tunnel junctions of traditional SETs. Our transistor with a total asymptotic resistance of 110 kOhm showed a very sharp Coulomb block

A. V. Kovalev, L. A. Akselrod

The magnetic properties of anisotropic films have been studied using 3D-neutron polarization analysis. The experimental facts refer to essential distinction of the sample states, magnetized in opposite directions. For an explanation of asymmetrical effects the model is offered, in which the fundamental theoretical principles of structural phase transitions a

Luis Craco

We study the simplified Hubbard (SH) model in the presence of a transverse field in the infinite dimension limit. The relevant one-particle Green's functions of the model are obtained by means a perturbative treatment of the hopping and of the transverse field around the atomic limit. We consider an analytical solution for the impurity problem. It is sho

O. S. Tarasov, A. P. Krekhov, L. Kramer

We analyse the homogeneous instabilities in a nematic liquid crystal subjected to plane steady Couette or Poiseuille flow in the case when the director is pre-aligned perpendicular to the flow plane taking into account weak anchoring at the confining surfaces. The critical shear rate decreases for decreasing anchoring strength and goes to zero in the limit o

P. Shiktorov, E. Starikov, V. Gruzinskis, L. Reggiani

It is shown that the quantum fluctuation dissipation theorem can be considered as a mathematical formulation in the spectral representation of Onsager hypothesis on the regression of fluctuations in physical systems. It is shown that the quantum fluctuation dissipation theorem can be generalized to an arbitrary stationary state.

S. Fratini, D. Feinberg, M. Grilli

The phase diagram of half-doped manganite systems of formula A_{0.5}A'_{0.5}MnO_3 is investigated within a single-orbital model incorporating magnetic double-exchange and superexchange, together with intersite Coulomb and electron-lattice interactions. Strong Jahn-Teller and breathing mode deformations compete together and result in shear lattice deforma

Bertrand M. Roehner, Carol H. Shiue

In economics comparative analysis plays the same role as experimental research in physics. In this paper we closely examine several methodological problems related to comparative analysis by investigating the specific example of grain markets in China and France respectively. This enables us to answer a question in economic history which has so far remained

Gerry Gilmore

The challenges of multi-wavelength astrophysics require new outlooks from those appropriate to traditional astronomy. The next generation of research scientists must be trained to exploit the potentiality now being provided for the first time. Just as importantly, the full range of available information must be indexed and made available, to avoid wasteful r

M. G. Watson

This paper describes the performance of XMM-Newton for serendipitous surveys and summarises the scope and potential of the XMM-Newton Serendipitous Survey. The role of the Survey Science Centre (SSC) in the XMM-Newton project is outlined. The SSC's follow-up and identification programme for the XMM-Newton serendipitous survey is described together with t

H. Boehringer, P. Schuecker, S. Komossa, J. Retzlaff

Based on the ROSAT All-Sky Survey we are constructing a sample of the X-ray brightest galaxy clusters for cosmological studies. We have already completed the compilation of a sample of about 1000 clusters in the sky excluding a 40 degree wide band around the galactic plane. We have demonstrated with the southern sample, which is the so far most complete, tha

M. D. Faison, W. M. Goss

We have used the Very Long Baseline Array (VLBA) and the Very Large Array (VLA) to image Galactic neutral hydrogen in absorption towards four compact extragalactic radio sources with 10 milliarcsecond resolution. Previous VLBA data by Faison et al (1998) have shown the existence of prominent structures in the direction of the extragalactic source 3C~138 with

H. Boehringer, E. Belsole, J. Kennea, K. Matsushita

We report performance verification observations of the giant elliptical galaxy M87 in the Virgo Cluster with the MOS, pn, and optical monitor instruments on board of XMM-Newton. With the energy sensitive imaging instruments MOS and pn we obtain the first spatially constrained X-ray spectra of the nucleus and the jet of the galaxy. The good photon statistics

C. S. Kochanek, M. A. Pahre, E. E. Falco

Galaxy morphological and spectroscopic types should be nearly independent of apparent magnitude in a local, magnitude-limited sample. Recent luminosity function surveys based on morphological classification of galaxies are substantially more successful at passing this test than surveys based on spectroscopic classifications. Among spectroscopic classifiers,

L. R. Jones, H. Ebeling, C. Scharf, E. Perlman

The evolution of the X-ray luminosity function of clusters of galaxies has been measured to z=0.9 using over 150 X-ray selected clusters discovered in the WARPS survey. We find no evidence for evolution of the luminosity function at any luminosity or redshift. The observations constrain the evolution of the space density of moderate luminosity clusters to be

C. S. Kochanek, M. A. Pahre, E. E. Falco, J. P. Huchra

We measured the K-band luminosity function using a complete sample of 4192 morphologically-typed 2MASS galaxies with 7 < K < 11.25 mag spread over 2.12 str. Early-type (T < -0.5) and late-type (T > -0.5) galaxies have similarly shaped luminosity functions, alpha_e=-0.92+/-0.10 and alpha_l=-0.87+/-0.09. The early-type galaxies are brighter, M_*e=-23.53+/-0.06

E. Trussoni, L. Feretti, S. Massaglia, P. Parma

We present BeppoSAX observations of the two FR I type radio galaxies Hercules A (3C 348) and MRC 0625-536 in the energy range $0.2 - 200$ keV. Data analysis shows that the X-ray flux from Hercules A is consistent with a diffuse thermal plasma emitting at $T \approx 4-5$ keV with a possible, but somewhat uncertain, contribution of a softer component at $T \ap

Gustavo Medina-Tanco, Torsten A. Ensslin

The isotropy in the ultra high energy cosmic ray (UHECR) flux observed by Yakutsk and AGASA experiments, is a very strong constraint to production and propagation models alike. Most of the scenarios proposed in the literature should produce a sizable anisotropy as either extragalactic luminous or dark matter is normally associated with the invoked particle s

N. Christlieb, L. Wisotzki, D. Reimers, D. Homeier

We describe automatic procedures for the selection of DA white dwarfs in the Hamburg/ESO objective-prism survey (HES). For this purpose, and the selection of other stellar objects (e.g., metal-poor stars and carbon stars), a flexible, robust algorithm for detection of stellar absorption and emission lines in the digital spectra of the HES was developed. Broa

Zuhui Fan, Tzihong Chiueh

We study Sunyaev-Zeldovich Effect (SZE) cluster counts in different cosmologies. It is found that even without the full knowledge of the redshift distribution of SZE clusters, one can still readily distinguish a flat universe with a cosmological constant from an open universe. We divide clusters into a low redshift group (with redshift z<0.5) and a high reds

Evgeny Griv, Michael Gedalin, David Eichler, Chi Yuan

The reaction of collective oscillations excited in the interaction between aperiodically growing Jeans-type gravity perturbations and stars of a rapidly rotating disk of flat galaxies is considered. An equation is derived which describes the change in the main body of equilibrium distribution of stars in the framework of the nonresonant weakly nonlinear theo

Gerry Gilmore

Quantification of the Galaxy&#39;s star formation history involves both the duration and the rate of formation, with these parameters being known with different precision for different populations. The early rate of star formation is knowable from modelling chemical element data, the recent rate directly from isochrone analyses of colour-magnitude data. The

Elisabeth Vangioni-Flam, Michel Casse

Oxygen is a much better evolutionary index than iron to follow the history of Lithium-Beryllium-Boron (LiBeB) since it is the main producer of these light elements at least in the early Galaxy. The O-Fe relation is crucial to the determination of the exact physical process responsible for the LiBeB production. Calculated nucleosynthetic yields of massive sta

Charles H. Lineweaver

I present a series of diagrams which illustrate why the cosmic microwave background (CMB) data favor certain values for the cosmological parameters. Various methods to extract these parameters from CMB and non-CMB observations are forming an ever-tightening network of interlocking constraints. I review the increasingly precise constraints in the Omega_m - Om

H. Papathanassiou, D. Psaltis

We study the spectra generated as a result of bulk Comptonization by relativistic electrons in radial flows onto compact objects. We solve numerically the general-relativistic radiative transfer equation in the Schwarzschild spacetime, in steady-state and under minimal assumptions. We show that power-law spectra result from multiple scatterings, in a way sim

R. J. Baxter

We consider the sum of dichromatic polynomials over non-separable rooted planar maps, an interesting special case of which is the enumeration of such maps. We present some known results and derive new ones. The general problem is equivalent to the $q$-state Potts model randomized over such maps. Like the regular ferromagnetic lattice models, it has a first-o

Michael N. Leuenberger, Daniel Loss

Shor and Grover demonstrated that a quantum computer can outperform any classical computer in factoring numbers and in searching a database by exploiting the parallelism of quantum mechanics. Whereas Shor&#39;s algorithm requires both superposition and entanglement of a many-particle system, the superposition of single-particle quantum states is sufficient f

Ryszard Manka, Ilona Bednarek

Nucleon and meson effective masses in the nonlinear Relativistic Mean - Field Theory (RMF) introducing a nonlinear omega - rho and sigma coupling motivated by the Quark Meson Coupling model (QMC) is explored. It is shown that, in contrast to the usual Walecka model, not only the effective nucleon mass m_{eff,N} but also the effective sigma, rho meson masses

Vijay Balasubramanian, Jan de Boer, Esko Keski-Vakkuri, Simon F. Ross

Conical defects, or point particles, in AdS_3 are one of the simplest non-trivial gravitating systems, and are particularly interesting because black holes can form from their collision. We embed the BPS conical defects of three dimensions into the N=4b supergravity in six dimensions, which arises from IIB string theory compactified on K3. The required Kaluz

Esteban Calzetta, Albert Roura, Enric Verdaguer

A linear open quantum system consisting of a harmonic oscillator linearly coupled to an infinite set of independent harmonic oscillators is considered; these oscillators have a general spectral density function and are initially in a Gaussian state. Using the influence functional formalism a formal Langevin equation can be introduced to describe the system&#

J. C. Montero, C. A. de S. Pires, V. Pleitez

In this work we show that we can generate neutrino masses through the type-II see-saw mechanism working at TeV scale in the context of a 331 model.

Andre&#39; LeClair

The all-orders beta function is used to study disordered Dirac fermions in 2D. The generic strong coupling fixed `points&#39; of anisotropic current-current interactions at large distances are actually isotropic manifolds corresponding to subalgebras of the maximal current algebra at short distances. The IR theories are argued to be current algebra cosets. W

F. Barra, P. Gaspard

We consider the classical evolution of a particle on a graph by using a time-continuous Frobenius-Perron operator which generalizes previous propositions. In this way, the relaxation rates as well as the chaotic properties can be defined for the time-continuous classical dynamics on graphs. These properties are given as the zeros of some periodic-orbit zeta

D. Lazzati, S. Covino, G. Ghisellini

While all but one Gamma-Ray Bursts observed in the X-ray band showed an X-ray afterglow, about 60 per cent of them have not been detected in the optical band. We demonstrate that in many cases this is not due to adverse observing conditions, or delay in performing the observations. We also show that the optically non-detected afterglows are not affected by p

Matthias Otto

Polymer rings in solution are either permanently entangled or not. Permanent topological restrictions give rise to additional entropic interactions apart from the ones arising due to mere chain flexibility or excluded volume. Conversely, entangled polymer rings systems may be formed by closing randomly entangled flexible linear chains. The dependance of link

R. H. Sanders

I consider the growth of inhomogeneities in a low-density baryonic, vacuum energy-dominated universe in the context of modified Newtonian dynamics (MOND). I first write down a two-field Langrangian-based theory of MOND (non-relativistic), which embodies several assumptions such as constancy of the MOND acceleration parameter, association of a MOND force with

Massimo Cencini, Alessandro Torcini

Infinitesimal and finite amplitude error propagation in spatially extended systems are numerically and theoretically investigated. The information transport in these systems can be characterized in terms of the propagation velocity of perturbations $V_p$. A linear stability analysis is sufficient to capture all the relevant aspects associated to propagation

M. Aunola

General properties of the tunnelling-charging Hamiltonian of a Cooper pair pump are examined with emphasis on the symmetries of the model. An efficient block-diagonalisation scheme and a compatible Fourier expansion of the eigenstates is constructed and applied in order to gather information on important observables. Systematics of the adiabatic pumping with

Toshifumi Futamase, Shijun Yoshida

We propose a possible measurement of the time variability of the vacuum energy using strong gravitational lensing events. As an example we take an Einstein cross lens HST 14176+5226 and demonstrate that the measurement of the velocity dispersion with the accuracy of $\pm$ 5 km/sec will have a chance to determine the time dependence of the vacuum energy as we

Peter Austing

We discuss the supersymmetry operator in the cohomological formulation of dimensionally reduced SYM. By establishing the cohomology, a large class of invariants are classified.

Alain Connes, Giovanni Landi

We give new examples of noncommutative manifolds that are less standard than the NC-torus or Moyal deformations of $\Rb^n$. They arise naturally from basic considerations of noncommutative differential topology and have non-trivial global features. The new examples include the instanton algebra and the NC-4-spheres $S^4_θ$. The noncommutative algebras $\Ac=C

Juraj Vavro

A simple method to obtain a canonical partition function for one dimensional lattice gas model is presented. The simplification is based upon rewriting a sum over all possible configurations to a sum over numbers of clusters in the system.

Qiang-Hua Wang, Jung Hoon Han, Dung-Hai Lee

Recently Chakravarty, Laughlin, Morr and Nayak made an interesting proposal that the cuprate superconductors possess a hidden ``d-density wave&#39;&#39; order. We study the implication of this proposal for the superfluid density ρ_s. We find that it predicts a temperature gradient |dρ_s/dT|_{T=0} that is strongly doping dependent near the critical doping (\a

Hongchen Fu, Xiaoguang Wang, Chong Li, Jiangong Wang

We study su(2) and su(1,1) displaced number states. Those states are eigenstates of density-dependent interaction systems of quantized radiation field with classical current. Those states are intermediate states interpolating between number and displaced number states. Their photon number distribution, statistical and squeezing properties are studied in deta

Xiwen Zhu, Ximing Fang, Xinhua Peng, Mang Feng

We have tested complementarity for the ensemble-averaged spin states of nuclei $^{13}$C in the molecule of $^{13}$CHCl$_{3}$ by the use of the spin states of another nuclei $^{1}$H as the path marker. It turns out that the wave-particle duality holds when one merely measures the probability density of quantum states, and that the wave- and particle-like beha

Jakub Rembielinski

Motivated by a number of recent experiments, we discuss in this paper a speculative but physically admissible form and solutions of effective Maxwell-like equations describing propagation of electromagnetic field in a medium which ``feels&#39;&#39; a quantum preferred frame.

Tanja I. Sachse, Ulrich Kleinekathoefer

The generalized Heitler-London (GHL) theory provides a straightforward way to express the potential energy surface of H_3 in terms of Coulomb and exchange energies which can be calculated either by perturbation theory or using the surface integral method (SIM). By applying the Rayleigh-Schroedinger perturbation theory, GHL theory for the quartet spin state o

Reinhold Brueckner

We show that the definition of an energy current for non-relativistic systems with action-at-a-distance is possible if the interaction respects Gausses law, i.e. if it is Coulomb-like. The energy current can transport kinetic and mass (excitation) energy but not potential energy.

Reinhold Brueckner

We propose an experiment using a three-gate quantum Hall device to probe the dependence of the integral quantum Hall effect (IQHE) on the shape of the lateral confining potential in edge regions. This shape can, in a certain configuration determine whether or not the IQHE occurs.

Yu. E. Titarenko, O. V. Shvedov, V. F. Batyaev, E. I. Karpikhin

114 cross sections for nuclide production in a 1.0 GeV proton-irradiated thin 208Pb target have been measured by the direct gamma spectrometry method using a high-resolution Ge detector. The gamma spectra were processed by the GENIE-2000 code. The ITEP-developed SIGMA code was used together with the PCNUDAT nuclear decay database to identify the gamma lines

A. P. Severyukhin, V. V. Voronov, D. Karadjov

A consistent treatment of the ground state correlations beyond the random phase approximation including their influence on the pairing and phonon-phonon coupling in nuclei is presented. A new general system of nonlinear equations for the quasiparticle phonon model (QPM) is derived. It is shown that this system contains as a particular case all equations deri

M. Betigeri, J. Bojowald, A. Budzanowski, A . Chatterjee

A stack of annular detectors made of high purity germanium was used to measure simultaneously $pd\to {^3H} π^+$ and $pd\to {^3He} π^0$ differential cross sections at beam momenta of 750 MeV/c, 800 MeV/c, and 850 MeV/c over a large angular range. The extracted total cross sections for the $pd\to {^3He} π^0$ reactions bridge a gap between near threshold data a

A. Schiller, M. Guttormsen, E. Melby, J. Rekstad

The experimental resonance parameters of the pygmy resonance in rare earth nuclei are compared to global parameters of the scissors-mode states. It is argued that the pygmy resonance in rare earth nuclei can be described in terms of orbital M1 strength observed in (gamma,gamma&#39;) experiments. The pygmy resonance is therefore interpreted as the scissors mo

Senya Shlosman, Michael A. Tsfasman

We review results about the density of typical lattices in $R^n.$ They state that such density is of the order of $2^{-n}.$ We then obtain similar results for random packings in $R^n$: after taking suitably a fraction $ν$ of a typical random packing $σ$, the resulting packing $τ$ has density $C(ν) 2^{-n},$ with a reasonable $C(ν).$ We obtain estimates on $C(

Juergen Jost, Guofang Wang

We analyze solutions of the Toda system and establish an optimal Moser-Trudinger inequality

P. T. Leung, Alec Maassen van den Brink, W. M. Suen, C. W. Wong

Supersymmetry (SUSY) in quantum mechanics is extended from square-integrable states to those satisfying the outgoing-wave boundary condition, in a Klein-Gordon formulation. This boundary condition allows both the usual normal modes and quasinormal modes with complex eigenvalues. The simple generalization leads to three features: the counting of eigenstates u

Andrei Kotlov

We derive the Gallai-Edmonds Structure Theorem from Hall&#39;s Theorem.

Andrei Kotlov

Using a mixture of linear algebra and statics, we derive what can be viewed as a slight generalization of the Coppersmith-Tetali-Winkler Identity $H(i,j)+H(j,k)+H(k,i)=H(j,i)+H(k,j)+H(i,k)$ for hitting times of a random walk.

Ulrich Goertz

We investigate the bad reduction of certain Shimura varieties (associated to the symplectic group). More precisely, we look at a model of the Shimura variety at a prime p, with parahoric level structure at p. We show that this model is flat, as conjectured by Rapoport and Zink, and that its special fibre is reduced.

Susumu Tanabé

We give an algebraic description of wave fronts that appear in strictly hyperbolic Cauchy problem. Concrete form of definig function of wave front issued from initial algebraic variety is obtained by the aid of the Gauss-Manin systems satisfied by Gel&#39;fand -Leray integrals.

Guyan Robertson, Tim Steger

This is an appendix to the paper {\bf Asymptotic K-theory for groups acting on $\tA_2$ buildings}, and contains the results of the computations performed by the authors.

Susumu Tanabe

One studies the system of differential equations satisfied by the hyperelliptic integral associated to a vanishing cycle defined for the versal deformation of the $A-μ$ singularity. As an application, the estimates on the multiplicity of zeros of the hyperelliptic integral are given as a linear function of the degree of present polynomials.

D. Kanevsky, Yu. Manin

Let $V$ be a plane smooth cubic curve over a finitely generated field $k.$ The Mordell-Weil theorem for $V$ states that there is a finite subset $P\subset V(k)$ such that the whole $V(k)$ can be obtained from $P$ by drawing secants and tangents through pairs of previously constructed points and consecutively adding their new intersection points with $V.$ Equ

Yuri I. Manin

A linear algebraic group $G$ is represented by the linear space of its algebraic functions $F(G)$ endowed with multiplication and comultiplication which turn it into a Hopf algebra. Supplying $G$ with a Poisson structure, we get a quantized version $F_q(G)$ which has the same linear structure and comultiplication, but deformed multiplication. This paper deve

C. Morosi, L. Pizzocchero

We consider the Sobolev norms of the pointwise product of two functions, and estimate from above and below the constants appearing in two related inequalities.

A. Ambrosetti, A. Malchiodi, S. Secchi

We prove some multiplicity results for a nonlinear equation of Schroedinger type with potential functions

Alain Connes

We describe basic concepts of noncommutative geometry and a general construction extending the familiar duality between ordinary spaces and commutative algebras to a duality between Quotient spaces and Noncommutative algebras. Basic tools of the theory, K-theory, Cyclic cohomology, Morita equivalence, Operator theoretic index theorems, Hopf algebra symmetry

Guyan Robertson

Let $Γ$ be a torsion free lattice in $G = \PGL(n+1,\FF)$, where $n\ge 1$ and $\FF$ is a non-archimedean local field. Then $Γ$ acts on the Furstenberg boundary $G/P$, where $P$ is a minimal parabolic subgroup of $G$. The identity element $\id$ in the crossed product $C^*$-algebra $C(G/P)\rtimes Γ$ generates a class $[\id]$ in the $K_0$ group of $C(G/P)\rtimes

Guyan Robertson, Tim Steger

Let $Γ$ be a torsion free lattice in $G=\PGL(3,{\mathbb F})$ where ${\mathbb F}$ is a nonarchimedean local field. Then $Γ$ acts freely on the affine Bruhat-Tits building ${\mathcal B}$ of $G$ and there is an induced action on the boundary $Ω$ of ${\mathcal B}$. The crossed product $C^*$-algebra ${\mathcal A}(Γ)=C(Ω) \rtimes Γ$ depends only on $Γ$ and is clas

Yan Soibelman

We suggest to compactify the universal covering of the moduli space of complex structures by non-commutative spaces. The latter are described by certain categories of sheaves with connections which are flat along foliations. In the case of abelian varieties this approach gives quantum tori as a non-commutative boundary of the moduli space. Relations to mirro

Herbert Clemens

The stable rationality of components of the moduli space of (unparametrized) rational curves in projective $n$-space with fixed normal bundle is proved, provided these components dominate the moduli space of immersed rational curves in the plane.

Matej Pavsic

Starting from the geometric calculus based on Clifford algebra, the idea that physical quantities are Clifford aggregates (&#34;polyvectors&#34;) is explored. A generalized point particle action (&#34;polyvector action&#34;) is proposed. It is shown that the polyvector action, because of the presence of a scalar (more precisely a pseudoscalar) variable, can

C. M. Hull

The free (4,0) superconformal theory in 6 dimensions and its toroidal dimensional reductions are studied. The reduction to four dimensions on a 2-torus has an $SL(2,\Z)$ duality symmetry that acts non-trivially on the linearised gravity sector, interchanging the linearised Einstein equations and Bianchi identities and giving a self-duality between strong and

J. Lukierski, P. C. Stichel, W. J. Zakrzewski

The model of nonrelativistic particles coupled to nonstandard (2+1)-gravity [1] is extended to include Abelian or non-Abelian charges coupled to Chern-Simons gauge fields. Equivalently, the model may be viewed as describing the (Abelian or non-Abelian) anyonic dynamics of Chern-Simons particles coupled, in a reparametrization invariant way, to a translationa

J. Weiss

The classical relativistic linear AAD interaction, introduced by the author, leads in the case of weak coupling to a pointlike particle capable to be sub- mitted to quantization via Feynman&#39;s path integrals along the line adequate to the requirements of the Pauli equation. In the discussed nonrelativistic case of the model the concept of spin is consider

J. Weiss

The model of a classical particle with the weak linear AAD potential is subjected to path integral quantization. The light cone constraints and peculiar properies of its internal variables permit to use in calculations commutative dynamics and apply path integrals for a matrix form of the transition amplitude. Quantization leads to description of a Dirac par

P. A. Horváthy

The dimensional reduction of the three-dimensional fermion-Chern-Simons model (related to Hopf maps) of Adam et el. is shown to be equivalent to (i) either the static, fixed--chirality sector of our non-relativistic spinor-Chern-Simons model in 2+1 dimensions, (ii) or a particular Heisenberg ferromagnet in the plane.

Piergiulio Tempesta, Alexander V. Turbiner, Pavel Winternitz

It is shown that all four superintegrable quantum systems on the Euclidean plane possess the same underlying hidden algebra $sl(3)$. The gauge-rotated Hamiltonians, as well as their integrals of motion, once rewritten in appropriate coordinates, preserve a flag of polynomials. This flag corresponds to highest-weight finite-dimensional representations of the

G. Bandelloni, S. Lazzarini

The purpose of this note is to show that W3 algebras originate from an unusual interplay between the breakings of the reparametrization invariance under the diffemorphism action on the cotangent bundle of a Riemann surface. It is recalled how a set of smooth changes of local complex coordinates on the base space are collectively related to a background withi