June 2001 arXiv papers — page 12

Pi-Gang Luan, Zhen Ye

Localization of acoustic waves in a one dimensional water duct containing many randomly distributed air filled blocks is studied. Both the Lyapunov exponent and its variance are computed. Their statistical properties are also explored extensively. The results reveal that in this system the single parameter scaling is generally inadequate no matter whether th

G. Jackeli, J. Ranninger

We study the ground state properties and the excitation spectrum of bosons which, in addition to a short-range repulsive two body potential, interact through the exchange of some dispersionless bosonic modes. The latter induces a time dependent (retarded) boson-boson interaction which is attractive in the static limit. Moreover the coupling with dispersionle

Masaru Onoda, Takahiro Mizusaki, Hideo Aoki

Effective mass of the composite fermion in the fractional quantum Hall system, which is of purely interaction originated, is shown, from a numerical study, to exhibit a curious nonmonotonic behavior with a staircase correlated with the number (=2,4,...) of attached flux quanta. This is surprising since the usual composite-fermion picture predicts a smooth be

Stephan M Dammer, Silvio R Dahmen, Haye Hinrichsen

Applying the theory of Yang-Lee zeros to nonequilibrium critical phenomena, we investigate the properties of a directed bond percolation process for a complex percolation parameter p. It is shown that for the Golden Ratio p=(1(+/-)sqrt(5))/2 and for p=2 the survival probability of a cluster can be computed exactly.

Minghui Kong, B. Partoens, F. M. Peeters

Structural and static properties of a classical two-dimensional (2D) system consisting of a finite number of charged particles which are laterally confined by a parabolic potential are investigated by Monte Carlo (MC) simulations and the Newton optimization technique. This system is the classical analog of the well-known quantum dot problem. The energies and

Alain Junod, Yuxing Wang, Frederic Bouquet, Pierre Toulemonde

The specific heat of two polycrystalline samples of MgB_2 is presented and analyzed (2 - 300 K, 0 - 16 T), together with magnetic properties. The main characteristics are a low density of states at the Fermi level, high phonon frequencies, and an anomalous temperature- and field- dependence of the specific heat at T < T_c. A two-gap model with a gap ratio of

Hsiu-Hau Lin, Tzay-Ming Hong

We study the quantum propagator in the semiclassical limit with hard-wall potentials. We show that, upon each reflection by the hard wall, a Berry phase $π$ is accumulated and leads to interferences between different classical trajectories. Including the Berry phase caused by the hard walls, the modified Van Vleck&#39;s formula is derived. We also discuss th

P. Chaddah

A recent paper [Physical Review {\bf B 64} 014508 (2001)] claims to present an exact method to extract the critical current density J$_C$ from the M-H hysteresis curve. We show that this claim appears unjustified.

M. J. Drinkwater, K. Bekki, W. J. Couch, S. Phillipps

We have used the 2dF spectrograph on the Anglo-Australian Telescope to obtain a complete spectroscopic sample of all objects in the magnitude range, Bj= 16.5 to 19.8, regardless of morphology, in an area centred on the Fornax Cluster of galaxies. Among the unresolved targets are five objects which are members of the Fornax Cluster. They are extremely compact

M. J. Drinkwater, C. Engel, S. Phillipps, J. B. Jones

Thanks to the 2dF spectrograph on the Anglo-Australian Telescope, we have recently completed the first stage of a complete spectroscopic survey more than one order of magnitude larger than any previous study, measuring 7000 spectra in a 6 sq.deg. area as part of our study of the Fornax Cluster. In this article we describe the public release of 3600 spectra f

J. S. Gallagher, L. D. Matthews

Low-mass disk galaxies with well-organized structures are relatively common in low density regions of the nearby Universe. They display a wide range in levels of star formation activity, extending from sluggishly evolving `superthin&#39; disk systems to nearby starbursts. Investigations of this class of galaxy therefore provides opportunities to test and def

M. A. McLaughlin, Z. Arzoumanian, J. M. Cordes, D. C. Backer

We discuss PSR J1740+1000, one of five pulsars recently discovered in a search of 470 square degrees at 430 MHz during the upgrade of the 305-m Arecibo telescope. The period of 154 ms and period derivative of 2.1 x 10^-14 s/s imply a spin-down age of 114 kyr that is smaller than 95% of all known pulsars. The youth and proximity of this pulsar make it a good

B. J. McCall, J. Thorburn, L. M. Hobbs, T. Oka

Using the new high resolution (~ 8 km/s) echelle spectrograph on the 3.5-m telescope at the Apache Point Observatory, we have begun a high sensitivity survey of the diffuse interstellar bands in a large sample of reddened stars. Now that we are two years into this long-term survey, our sample includes over 20 reddened stars which show at least one of the DIB

A. V. Stepanov, B. Kliem, V. V. Zaitsev, E. Fuerst

An intense radio flare on the dMe star AD Leo, observed with the Effelsberg radio telescope and spectrally resolved in a band of 480 MHz centred at 4.85 GHz is analysed. A lower limit of the brightness temperature of the totally right handed polarized emission is estimated as T_b ~ 5x10^10 K (with values T_b > ~3x10^13 K considered to be more probable), whic

J. Gerssen, R. P. van der Marel, D. Axon, C. Mihos

WFPC2 images and STIS spectroscopic observations are presented of the double nucleus in the merger system NGC 6240. We find that: (a) the kinematics of the ionized gas is similar to that of the molecular gas, despite a different morphology; (b) the gaseous and stellar kinematics are quite different, suggesting an early merger stage; (c) neither the gaseous n

David Branch

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared to photospheric-phase spectra of Type Ib supernovae (SNe Ib). Although the synthetic spectra are based on many simplifying approximations, including spherical symmetry, they account well for the observed spectra. Our sample of SNe Ib obeys a tight relation

C. Sneden

Abundance ratios of radioactive to stable neutron-capture elements in very metal-poor stars may be used to estimate the age of our Galaxy. But extracting accurate ages from these data requires continuing work on many fronts: a) identification of more low metallicity stars with neutron-capture element excesses; b) acquisition of the best high resolution stell

R. I. Raikin, A. A. Lagutin, N. Inoue, A. Misaki

Theoretical predictions for lateral distribution function of electrons in extensive air showers based on scaling formalism are presented. Our results are tested by comparison with AGASA experimental data taking into account the contribution of low-energy muons and simultaneously the effect of scintillation detectors response, according to recent simulation r

R. I. Raikin, A. A. Lagutin, N. Inoue, A. Misaki

Detailed theoretical study of the mean square radius of extensive air shower electrons has been made in connection with further development of scaling formalism for electron lateral distribution function. A very simple approximation formula, which allows joint description of all our results obtained in wide primary energy range and for different observation

Loretta Dunne, Stephen Eales

This is the second in a series of papers presenting results from the SCUBA Local Universe Galaxy Survey. In our first paper we provided 850 micron flux densities for 104 galaxies selected from the IRAS Bright Galaxy Sample and we found that the 60, 100 micron (IRAS) and 850 micron (SCUBA) fluxes could be adequately fitted by emission from dust at a single te

Carlos Allende Prieto, David L. Lambert, Martin Asplund

We reexamine closely the solar photospheric line at 6300 A, which is attributed to a forbidden line of neutral oxygen, and is widely used in analyses of other late-type stars. We use a three-dimensional time-dependent hydrodynamical model solar atmosphere which has been tested successfully against observed granulation patterns and an array of absorption line

Katia M. Ferriere

We review the current knowledge and understanding of the interstellar medium of our galaxy. We first present each of the three basic constituents - ordinary matter, cosmic rays, and magnetic fields - of the interstellar medium, laying emphasis on their physical and chemical properties inferred from a broad range of observations. We then position the differen

Fidel Cruz, David Merritt

We present the results of N-body simulations of the accretion of high-density dwarf galaxies by low-density giant galaxies. Both galaxies contain power-law central density cusps and point masses representing supermassive black holes; the ratio of galaxy masses is 3:1. The cusp of the dwarf galaxy is always disrupted during the merger, leading to a remnant wi

S. P. Littlefair, V. S. Dhillon, T. R. Marsh

We present the K-band infrared spectrum of the intermediate polar XY Ari. The spectrum confirms the cataclysmic binary nature of XY Ari, showing emission lines of HeI (2.0587 microns) and the Brackett and Paschen series of HI. The broad nature of these lines suggest an origin in an accretion disc. The spectrum is strongly reddened by absorption within the mo

Xiang-Ping Wu, Yan-Jie Xue

We present an estimate of the X-ray background (XRB) spectrum from the warm-hot intergalactic medium (IGM) associated with groups and clusters of galaxies, using purely the observationally determined X-ray luminosity function (XLF) and X-ray luminosity (Lx) - temperature (T) relations for groups and clusters. As compared with previous semi-analytic models ba

R. T. Edwards, W. van Straten, M. Bailes

We have conducted a search of 19 southern Galactic globular clusters for sub-millisecond pulsars at 660 MHz with the Parkes 64-m radio telescope. To minimize dispersion smearing we used the CPSR baseband recorder, which samples the 20 MHz observing band at the Nyquist rate. By possessing a complete description of the signal we could synthesize an optimal fil

K. Okumura, R. Enomoto, A. Asahara, G. V. Bicknell

A preliminary result from Markarian 421 observations in the energy region above 10 TeV with the CANGAROO-II 10 m telescope is presented. In January 2001, the HEGRA group reported that Markarian 421 had become very active, with flux levels up to 4 times that of the Crab Nebula. As a result, we observed Mkn 421 during six nights from January 24th to February 1

Nicolai Bissantz, Axel Munk

The assumption that a parametric class of functions fits the data structure sufficiently well is common in fitting curves and surfaces to regression data. One then derives a parameter estimate resulting from a least squares fit, say, and in a second step various kinds of chi^2 goodness of fit measures, to assess whether the deviation between data and estimat

V. A. Dubrovskiy

Some results are presented of the Earth&#39;s microseismic background. It is assumed that background peaks should correspond to the resonance gravity-wave exchange in the system of two gravity-connected bodies. The microseismic spectrum is compared with the distribution of gravity potential of the nearest stars. A close peak-to-peak correspondence is found.

Sanjay Bhatnagar, Rajaram Nityananda

Mechanical and electronic imperfections can result into polarization leakage in individual antennas of a radio interferometer. Such leakages manifest themselves as closure errors even in co-polar visibility measurements of unpolarized sources. This paper describes and tests a method for the study of polarization leakage for radio interferometric telescopes u

Masaki Mori, the CANGAROO collaboration

Preliminary results from CANGAROO-II, a 10 m imaging Cherenkov telescope, in Woomera, South Australia are presented. They include the confirmation of detections of TeV gamma-ray sources we have reported using a 3.8 m telescope, CANGAROO-I. Also the status of the construction of an array of four 10 m telescopes, called CANGAROO-III, is reported. The first tel

M. Mori, A. Asahara, G. V. Bicknell, R. W. Clay

We report on the status of the construction of an array of four 10 m atmospheric Cherenkov telescopes for gamma-ray astronomy, near Woomera, in South Australia -- the CANGAROO-III project. The first telescope of this array is the upgraded version of the CANGAROO-II 7 m telescope and has been in operation since March 2000. The second telescope, an improved ve

Francois Schweizer

Globular clusters formed in galactic mergers (e.g., The Antennae) can now be studied at different stages of their evolution. In young merger remnants (e.g., NGC 7252) these &#34;second-generation&#34; globulars appear by the hundreds as young halo clusters of roughly solar metallicity. While at first bluer and much more luminous than old metal-poor globulars

Robert C. Myers

We discuss the nonabelian world-volume action which governs the dynamics of N coincident Dp-branes. In this theory, the branes&#39; transverse displacements are described by matrix-valued scalar fields, and so this is a natural physical framework for the appearance of noncommutative geometry. One example is the dielectric effect by which Dp-branes may be pol

Steven B. Giddings, Scott Thomas

If the fundamental Planck scale is of order a TeV, as the case in some extra-dimensions scenarios, future hadron colliders such as the Large Hadron Collider will be black hole factories. The non-perturbative process of black hole formation and decay by Hawking evaporation gives rise to spectacular events with up to many dozens of relatively hard jets and lep

Guy D. Moore, Ann E. Nelson

Recently, interesting 4-D Lorentz violating models have been proposed, in which all particles have a common maximum velocity $c$, but gravity propagates (in the preferred frame) with a different maximum velocity $c_g \neq c$. We show that the case $c_g < c$ is very tightly constrained by the observation of the highest energy cosmic rays. Assuming a galactic

Enke Wang, Xin-Nian Wang

Stimulated gluon emission and thermal absorption in addition to induced radiation are considered for an energetic parton propagating inside a quark- gluon plasma. In the presence of thermal gluons, stimulated emission reduces while absorption increases the parton&#39;s energy. The net effect is a reduction of the parton energy loss. Though decreasing asympto

J. B. Natowitz, R. Wada, K. Hagel, T. Keutgen

Data from a number of different experimental measurements have been used to construct caloric curves for five different regions of nuclear mass. These curves are qualitatively similar and exhibit plateaus at the higher excitation energies. The limiting temperatures represented by the plateaus decrease with increasing nuclear mass and are in very good agreeme

Xin Wan, Kun Yang, E. H. Rezayi

We study the interplay of interaction, confining potential and effects of finite temperature at the edge of a quantum Hall liquid. Our exact diagonalization calculation indicates that edge reconstruction occurs in the fractional quantum Hall regime for a variety of confining potential, including ones that correspond to a &#34;sharp&#34; edge. Our finite temp

D. N. Argyriou, P. J. Brown, J. S. Gardner, R. H. Heffner

In the ferromagnetic metallic state of the colossal magnetoresistive (CMR) manganite La1.2Sr1.8Mn2O7, the spin density distribution is essentially in agreement with the standard picture in which the unpaired electrons occupy the three t2g orbitals, dxy, dyz, and dxz. However we find a small spin density ~4% of the total Mn spin) on the apical O(2) oxygen ato

N. G. Zhang, C. L. Henley, C. Rischel, K. Lefmann

We study the low-lying energy clustering patterns of quantum antiferromagnets with p sublattices (in particular p=4). We treat each sublattice as a large spin, and using second-order degenerate perturbation theory, we derive the effective (biquadratic) Hamiltonian coupling the p large spins. In order to compare with exact diagonalizations, the Hamiltonian is

Seung-chan Ahn, Gene Kim, MyungHo Kim

We describe in a rudimentary fashion how SVM(support vector machine) plays the role of classifier in a mathematical setting. We then discuss its application in the study of multiple SNP(single nucleotide polymorphism) variations. Also presented is a set of preliminary test results with clinical data.

K. Konishi, L. Spanu

We discuss general properties and possible types of magnetic vortices in non-Abelian gauge theories (we consider here $G= SU(N), SO(N), USp(2N)$) in the Higgs phase. The sources of such vortices carry &#34;fractional&#34; quantum numbers such as $Z_n$ charge (for SU(N)), but also full non-Abelian charges of the dual gauge group. If such a model emerges as an

S. Antoci, L. Mihich

Let us abandon for a moment the strict epistemological standpoint of quantum field theory, that eventually comes to declare nonsensical any question about the photon posed outside the quantum theoretical framework. We can then avail of the works by Whittaker et al. and by Synge about the particle and the wave model of the photon in the vacuum of general rela

Luis A. Anchordoqui, Haim Goldberg

Assuming that the hard gamma-ray emission of Cen A is a result of synchrotron radiation of ultra-relativistic electrons, we derive a lower bound on the local extragalactic magnetic field, $B> 10^{-8}$ G. This result is consistent with (and close to) upper bounds on magnetic fields derived from consideration of cosmic microwave background distortions and Fara

Richard P. Sear

Homogeneous nucleation of a new phase near an Ising-like critical point of another phase transition is studied. A scaling analysis shows that the free energy barrier to nucleation contains a singular term with the same scaling as the order parameter associated with the critical point. The total magnetisation of the nucleus scales as the response function and

Shi-Lin Zhu, C. M. Maekawa, B. R. Holstein, M. J. Ramsey-Musolf

We analyze the real photon asymmetry $A^\pm_γ$ for the parity violating (PV) $π^\pm$ production on the $Δ$ resonance via the reactions ${\vec γ} + p \to Δ^+ \to π^+ + n$ and ${\vec γ} + d \to Δ^0 + p \to π^- + p + p$. This asymmetry is nonvanishing due to a PV $γN Δ$ coupling constant, $d^\pm_Δ$. We argue that an experimental determination of this coupling w

Emil Martinec, Will McElgin

We consider worldsheet string theory on $Z_N$ orbifolds of $AdS_3$ associated with conical singularities. If the orbifold action includes a similar twist of $S^3$, supersymmetry is preserved, and there is a moduli space of vacua arising from blowup modes of the orbifold singularity. We exhibit the spectrum, including the properties of twisted sectors and sta

Hua Wu

A clear physics picture of TbBaCo$_{2}$O$_{5.5}$ is revealed on the basis of density functional theory calculations. An antiferromagnetic (AFM) superexchange coupling between the almost high-spin Co$^{3+}$ ions competes with a ferromagnetic (FM) interaction mediated by both p-d exchange and double exchange, being responsible for the observed AFM-FM transitio

J. Schuster, A. Marte, S. Amtage, B. Sang

Collisional avalanches are identified to be responsible for an 8-fold increase of the initial loss rate of a large 87-Rb condensate. We show that the collisional opacity of an ultra-cold gas exhibits a critical value. When exceeded, losses due to inelastic collisions are substantially enhanced. Under these circumstances, reaching the hydrodynamic regime in c

Petr Zavada

The spin structure functions of the system of quasifree fermions on mass shell are studied in a consistently covariant approach. Comparison with the basic formulas following from the quark-parton model reveals the importance of the fermion motion inside the target for the correct evaluation of the spin structure functions. In particular it is shown, that reg

Michele Caselle, Martin Hasenbusch, Andrea Pelissetto, Ettore Vicari

By using conformal-field theory, we classify the possible irrelevant operators for the Ising model on the square and triangular lattices. We analyze the existing results for the free energy and its derivatives and for the correlation length, showing that they are in agreement with the conformal-field theory predictions. Moreover, these results imply that the

Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov

We present a new NLO QCD analysis of the world data on inclusive polarized deep inelastic scattering. Comparing to our previous analysis: i) the values of g_A and a_8=3F-D are updated ii) the MRST&#39;99 instead of the MRST&#39;98 parametrization for the input unpolarized parton densities is used and iii) the recent SLAC E155 proton data on the spin asymmetr

Yasuhiro Utsumi, Hiroshi Imamura, Masahiko Hayashi, Hiromichi Ebisawa

We theoretically investigate effects of quantum fluctuation between even and odd charge states on the transport properties of a normal-superconducting-normal single-electron tunneling transistor. The charge fluctuation is discussed beyond the orthodox theory. We find that the charging energy renormalization enhances the parity effect: The Coulomb blockade re

S. A. Mikhailov

Exact-diagonalization studies of few-electron quantum dots and disks are performed, with the aim to investigate a Wigner cluster -- Fermi liquid crossover in zero magnetic field at varying strength of Coulomb interaction. A clear indication of a transition of a liquid-solid type in the ground state is found in a more adequate quantum-disk model.

A. E. Shalyt-Margolin, V. I. Strazhev, A. Ya. Tregubovich

The Halting problem of a quantum computer is considered. It is shown that if halting of a quantum computer takes place the associated dynamics is described by an irreversible operator.

Chongxing Yue, Qingjun Xu, Guoli Liu

We consider the lepton-flavor violating(LFV) processes $l_{i}\to l_{j}γ$ in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson $Z^{\prime}$ predicted by TC2 models can give significantly contributions to these processes via the flavor changing couplings. The present experimental bound on the LFV process $μ\to eγ$ giv

M. Koniorczyk, V. Buzek, J. Janszky

We present a unified approach to quantum teleportation in arbitrary dimensions based on the Wigner-function formalism. This approach provides us with a clear picture of all manipulations performed in the teleportation protocol. In addition within the framework of the Wigner-function formalism all the imperfections of the manipulations can be easily taken int

T. Totani, Y. Yoshii, F. Iwamuro, T. Maihara

Galaxy counts in the K band, (J-K)-colors, and apparent size distributions of faint galaxies in the Subaru Deep Field (SDF) down to K~24.5 were studied in detail. Special attention has been paid to take into account various selection effects including the cosmological dimming of surface brightness, to avoid any systematic bias which may be the origin of cont

Martino Romaniello, Nino Panagia, Salvatore Scuderi, Roberto Gilmozzi

The combination of the unprecedented spatial resolution attainable with WFPC2 on board HST and of the large collecting area of the VLT makes it possible to study in detail the low mass pre-Main Sequence stars in galaxies other than our own. Here we present the results of our studies of two star forming environments in our closest galactic neighbor, the Large

Giuseppe Gaeta

We show that a nonlinear dynamical system in Poincare&#39;-Dulac normal form (in $\R^n$) can be seen as a constrained linear system; the constraints are given by the resonance conditions satisfied by the spectrum of (the linear part of) the system and identify a naturally invariant manifold for the flow of the ``parent&#39;&#39; linear system. The parent sys

Giuseppe Gaeta

We classify the possible behaviour of Poincaré-Dulac normal forms for dynamical systems in $R^n$ with nonvanishing linear part and which are equivariant under (the fundamental representation of) all the simple compact Lie algebras and thus the corresponding simple compact Lie groups. The ``renormalized forms&#39;&#39; (in the sense of previous work by the au

H1 Collaboration, C. Adloff

The total cross section for the photoproduction process with a leading proton in the final state has been measured at gamma p centre-of-mass energies W of 91, 181 and 231 GeV. The measured cross sections apply to the kinematic range with the transverse momentum of the scattered proton restricted to p_Tproton <= 0.2 GeV and 0.68 <= z <= 0.88, where z = E_p&#3

Ting-Wai Chiu

A novel feature of a Ginsparg-Wilson lattice Dirac operator is discussed. Unlike the Dirac operator for massless fermions in the continuum, this lattice Dirac operator does not possess topological zero modes for any topologically-nontrivial background gauge fields, even though it is exponentially-local, doublers-free, and reproduces correct axial anomaly for

Frederic Zagury

This paper examines the relationship between spectra of stars of same spectral type with extremely low reddenings. According to the standard theory, the relationship between the spectrum of stars with same spectral type and small, but different reddenings should be different in the optical and in the UV. This difference is not observed: the ratio of the spec

Piljin Yi

We compute gravitational and axial anomaly for D-type (2,0) theories realized on N pairs of coincident M5-branes at R^5/Z_2 orbifold fixed point. We first summarize work by Harvey, Minasian, and Moore on A-type (2,0) theories, and then extend it to include the effect of orbifold fixed point. The net anomaly inflow follows when we further take into account th

Frederic Zagury

The comparison, undertaken in preceding papers, of the UV observations of nebulae and of reddened stars reveals contradictory aspects of interstellar extinction. The aim of this paper is to understand the implications hidden behind the apparent contradictions. The questions treated will be: how can small grains with an isotropic phase function make an apprec

Frederic Zagury

The spectrum of HD46223 was established from the optical to the far UV and normalized by the spectrum of a non reddened star of same spectral type. The resulting spectrum is separated into two components. One is the direct starlight. The second is an additional component of light scattered at small angles. In the optical the spectrum is dominated by direct s

Hongwei Xiong, Shujuan Liu, Guoxiang Huang, Zhijun Xu

We investigate the fluctuations of the condensate in the ideal and weakly interacting Bose gases confined in a box of volume V within canonical ensemble. Canonical ensemble is developed to describe the behavior of the fluctuations when different methods of approximation to the weakly interacting Bose gases are used. Research shows that the fluctuations of th

L. Chatterjee, M. R. Strayer, J. S. Wu

Neutrino Bremsstrahlung of flavor-degenerate pairs in the field of a nucleus is of potential importance for neutrino astrophysics and is representative of a class of processes connecting leptonic electroweak sectors to real or virtual photons. We focus on first generation flavor production by both electron and muon neutrinos and present Standard Model cross

W. Y. Wang, Y. L. Wu

B --> rho l nu decay is analyzed in the effective theory of heavy quark with infinite mass limit. The matrix element relevant to the heavy to light vector meson semileptonic decays is parametrized by a set of four heavy flavor-spin independent universal wave functions at the leading order of effective theory. The form factors are calculated at the leading 1/

A. de la Macorra, C. Stephan-Otto

We show that a positive accelerating universe can be obtained simply by the dynamics of a non-abelian gauge group. It is the condensates of the chiral fields that obtain a negative power potential, below the condensation scale, and allow for a quintessence interpretation of these fields. The only free parameters in this model are $N_c$ and $N_f$ and the numb

Kenton K. Yee

In recent years, political economists, financial economists, and other social scientists have introduced spin and lattice models into their theoretical tool kit. To this end, the modeling skills of hard scientists may be of assistance. This lecture introduces examples of how these models are used. A simple dynamical model of how legal rules evolve and propag

H. H. Adamyan, S. B. Manvelyan, G. Yu. Kryuchkyan

We propose an anharmonic oscillator driven by two periodic forces of different frequencies as a new time-dependent model for investigating quantum dissipative chaos. Our analysis is done in the frame of statistical ensemble of quantum trajectories in quantum state diffusion approach. Quantum dynamical manifestation of chaotic behavior, including the emergenc

M. S. Altschul, B. Altschul

Recent work using spontaneous parametric down-conversion (SPDC) has made possible investigations of the Einstein-Podolsky-Rosen paradox in its original (position-momentum) form. We propose an experiment that uses SPDC photon pairs to measure through which slit a photon passes while simultaneously observing double-slit interference.

E. M. Beniaminov

There are considered some corollaries of certain hypotheses on the observation process of microphenomena. We show that an enlargement of the phase space and of its motion group and an account for the diffusion motions of microsystems in the enlarged space, the motions which act by small random translations along the enlarged group, lead to observable quantum

Peter Rowlands, J. P. Cullerne

A representation of the Dirac algebra, derived from first principles, can be related to the combinations of unit charges which determine particle structures. The algebraic structure derives from a broken symmetry between 4-vectors and quaternions which can be applied to the broken symmetry between the three nongravitational interactions. The significance of

Renat Kh. Gainutdinov

The problem is considered of describing the dynamics of quantum systems generated by a nonlocal in time interaction. It is shown that the use of the Feynman approach to quantum theory in combination with the canonical approach allows one to extend quantum dynamics to describe the time evolution in the case of such interactions. In this way, using only the cu

G. S. Agarwal, Tarak Nath Dey, Sunish Menon

We show how the application of a coupling field connecting the two lower metastable states of a lambda-system can produce a variety of new results on the propagation of a weak electromagnetic pulse. In principle the light propagation can be changed from subluminal to superluminal. The negative group index results from the regions of anomalous dispersion and

Volodymyr Krasnoholovets

A new concept of the constitution of Nature is proposed. The constructed submicroscopic quantum mechanics is deterministic and is characterised by elementary excitations of the space net that is treated as the tessellation of balls, or superparticles. Said excitations called &#34;inertons&#34; accompany any canonical particle when it moves. It is shown theor

M. Ibison

This paper is an investigation of the class of real classical Markov processes without a birth process that will generate the Dirac equation in 1+1 dimensions. The Markov process is assumed to evolve in an extra (ordinal) time dimension. The derivation requires that occupation by the Dirac particle of a space-time lattice site is encoded in a 4 state classic

V. V. Kozlov, S. Wallentowitz, S. Raghavan

We show that an incident wavepacket at the boundary to a medium with extremely slow group velocity, experiences enhanced reflection and a substantial spatial and temporal distortion of the transmitted wave packet. In the limit of vanishing group velocity, light cannot be transferred into the medium due to its perfect reflectivity.

Peter Rowlands

A core level of basic information for physics is identified, based on an analysis of the characteristics of the parameters space, time, mass and charge. At this level, it is found that certain symmetries operate, which can be used to explain certain physical facts and even to derive new mathematical theorems. Applications are made to classical mechanics, ele

Denis Puy

The dark Universe corresponds to the period between the thermal decoupling matter-radiation and the formation of the first objects. During this epoq, molecules can appeared. In this talk, I will recall the nucleosynthesis processes, then the chemistry of the primordial Universe. I will discuss the influence of the primordial molecules on the protocloud evolu

Eric Baird

We present diagrams and simple calculations for the apparent (i.e. photographable) length of a moving ruler skimming the observer&#39;s position, under three different classes of model. Special relativity&#39;s predictions in this particular situation are the root-product average of the two more basic first-order predictions generated by simple &#34;propagat

O. Benhar, A. Fabrocini, S. Fantoni, A. Yu. Illarionov

We analyze the properties of deuteron-like structures in infinite, correlated nuclear matter, described by a realistic hamiltonian containing the Urbana $v_{14}$ two-nucleon and the Urbana TNI many-body potentials. The distribution of neutron-proton pairs, carrying the deuteron quantum numbers, is obtained as a function of the total momentum by computing the

Kenji Kajiwara, Masatoshi Noumi, Yasuhiko Yamada

We give a birational realization of affine Weyl group of type $A^{(1)}_{m-1} \times A^{(1)}_{n-1}$. We apply this representation to construct some discrete integrable systems and discrete Painlevé equations. Our construction has a combinatorial counterpart through the ultra-discretization procedure.

Michele Mulazzani, Andrei Vesnin

We discuss 3-manifolds which are cyclic coverings of the 3-sphere, branched over 2-bridge knots and links. Different descriptions of these manifolds are presented: polyhedral, Heegaard diagram, Dehn surgery and coloured graph constructions. Using these descriptions, we give presentations for their fundamental groups, which are cyclic presentations in the cas

Louis Funar, Siddhartha Gadgil

We introduce the notion of a topological geodesic in a 3-manifold. Under suitable hypotheses on the fundamental group, for instance word-hyperbolicity, topological geodesics are shown to have the useful properties of, and play the same role in several applications as, geodesics in negatively curved spaces. This permits us to obtain virtual rigidity results f

V. I. Burenkov, E. B. Davies

We prove the equivalence of Hardy- and Sobolev-type inequalities, certain uniform bounds on the heat kernel and some spectral regularity properties of the Neumann Laplacian associated with an arbitrary region of finite measure in Euclidean space. We also prove that if one perturbs the boundary of the region within a uniform Hölder category then the eigenvalu

David J. Aldous, Antar Bandyopadhyay

Use each of n exact samples as the initial state for a MCMC sampler run for m steps. We give confidence intervals for accuracy of estimators which are always valid and which, in certain settings, are almost as good as the intervals one would obtain if the (unknown) mixing time of the chain were known.

A. Rita Gaio, Dietmar A. Salamon

We study pseudoholomorphic curves in symplectic quotients as adiabatic limits of solutions of a system of nonlinear first order elliptic partial differential equations in the ambient symplectic manifold. The symplectic manifold carries a Hamiltonian group action. The equations involve the Cauchy-Riemann operator over a Riemann surface, twisted by a connectio

Paul E. Gunnells

These are the notes from a survey talk given at Arbeitstagung 2001 covering the author&#39;s work with Lev Borisov and Sorin Popescu on toric varieties, modular forms, and equations of modular curves.

Damir Filipovic, Josef Teichmann

This paper discusses finite-dimensional (Markovian) realizations (FDRs) for Heath-Jarrow-Morton interest rate models. We consider a d-dimensional driving Brownian motion and stochastic volatility structures that are non-degenerate smooth functionals of the current forward rate. In a recent paper, Björk and Svensson give sufficient and necessary conditions fo

Jaume Gudayol

We prove a Nash-Moser type inverse function theorem in Frechet spaces for functions with approximate inverses, allowing for a loss of derivatives proportional to $n$ in the way of Lojasiewicz and Zehnder.

Mikhail G. Katz, Alexander I. Suciu

Given a pair of integers m and n such that 1 < m < n, we show that every n-dimensional manifold admits metrics of arbitrarily small total volume, and possessing the following property: every m-dimensional submanifold of less than unit m-volume is necessarily torsion in homology. This result is different from the case of a pair of complementary dimensions, fo

Morihiko Saito

We show that Mildenhall&#39;s theorem implies that the indecomposable higher Chow group of a self-product of an elliptic curve over the complex number field is infinite dimensional, if the elliptic curve is modular and defined over rational numbers. For the moment we cannot prove even the nontriviality of the indecomposable higher Chow group by a complex ana

N. F. Benschop

The finite ring Z_k = Z(+,.) mod p^k of residue arithmetic with odd prime power modulus is analysed. The cyclic group of units G_k in Z_k(.) has order (p-1)p^{k-1}, implying product structure G_k = A_k B_k. Here core A_k of order p-1 is an extension for k >1 of Fermat&#39;s Small Theorem (FST*), where n^p == n (mod p^k) for each core residue, while extension

Tian-Jun Li, Ai-Ko Liu

Let M be a closed oriented smooth 4-manifold admitting symplectic structures. If M is minimal and has b^+=1, we prove that there is a unique symplectic canonical class up to sign, and any real second cohomology class of positive square is represented by symplectic forms. Similar results hold when M is not minimal.

Gary Felder, Lev Kofman, Andrei Linde

Spontaneous symmetry breaking usually occurs due to the tachyonic (spinodal) instability of a scalar field near the top of its effective potential at $ϕ= 0$. Naively, one might expect the field $ϕ$ to fall from the top of the effective potential and then experience a long stage of oscillations with amplitude O(v) near the minimum of the effective potential a