February 2002 arXiv papers — page 2

P. M. Ostrovsky, M. A. Skvortsov, M. V. Feigel'man

Semiclassical theory of proximity effect predicts a gap E_g \sim hD/L^2 in the excitation spectrum of a long diffusive SNS junction. Mesoscopic fluctuations lead to anomalously localized states in the normal part of the junction. As a result, a non-zero, yet exponentially small, density of states appears at energies below E_g. In the framework of the superma

Baolin Wang, Guanghou Wang, Jijun Zhao

The thermal stability and melting behavior of ultrathin titanium nanowires with multi-shell cylindrical structures are studied using molecular dynamic simulation. The melting temperatures of titanium nanowires show remarkable dependence on wire sizes and structures. For the nanowire thinner than 1.2 nm, there is no clear characteristic of first-order phase t

A. V. Balatsky, Jian-Xin Zhu

We consider the temperature fluctuations of a small object. Classical fluctuations of the temperature have been considered for a long time. Using the Nyquist approach, we show that the temperature of an object fluctuates when in a thermal contact with a reservoir. For large temperatures or large specific heat of the object $C_v$, we recover standard results

Alexander Shnirman, Yuriy Makhlin, Gerd Schön

Motivated by recent experiments with Josephson-junction circuits we reconsider decoherence effects in quantum two-level systems (TLS). On one hand, the experiments demonstrate the importance of 1/f noise, on the other hand, by operating at symmetry points one can suppress noise effects in linear order. We, therefore, analyze noise sources with a variety of p

A. J. Wagner

In this article we show that the phase-ordering scaling state for binary fluids is not necessarily unique and that local correlations in the initial conditions can be responsible for selecting the scaling state. We describe a new scaling state for symmetric volume fractions that consists of drops of the one component suspended in a matrix of the other. The u

Isaac Shlosman

We discuss different aspects of nested bar systems, both observational and theoretical. Such systems consist of a large-scale primary bar leading to the formation of a sub-kpc size secondary bar, whose pattern speed differs substantially from that of the main bar. Specifically, we focus on the origin and gravitational decoupling of nested bars, and their cha

K. O'Neil

Calibrating telescope data is one of the most important issues an observer faces. In this chapter we describe a number of the methods which are commonly used to calibrate radio telescope data in the centimeter wavelength regime. This includes a discussion of the various methods often used in determining the temperature and gain of a telescope, as well as som

Eric L. Sandquist, Jon J. Dokter, D. N. C. Lin, Rosemary A. Mardling

We examine the overall likelihood that the consumption of a giant planet could pollute its host star. First, we show that the detection of 6Li in SWPs could be used to distinguish between giant planet formation theories, and can be used to detect the consumption of giant planets independent of planet mass. Second, we examine the probability that giant planet

T. J. Davidge, S. Courteau

J, H, and K' images obtained with the Canada-France-Hawaii Telescope adaptive optics system are used to investigate the star-forming histories of the central regions of the Sc galaxies NGC 247 and NGC 2403. The brightest resolved red stars within 15 arcsec of the nucleus of each galaxy are red supergiants, indicating that the central few hundred parsecs

Ellen G. Zweibel, Fabian Heitsch, Yuhong Fan

The generation and evolution of astrophysical magnetic fields occurs largely through the action of turbulence. In many situations, the magnetic field is strong enough to influence many important properties of turbulence itself. Numerical simulation of magnetized turbulence is especially challenging in the astrophysical regime because of the high magnetic Rey

L. V. Toth, Cs. Kiss, M. Juvela, M. Stickel

A faint $I_{\rm 170}=4$ MJysr$^{-1}$ bipolar globule was discovered with the ISOPHOT 170 $μ$m Serendipity Survey (ISOSS). ISOSS J 20246+6541 is a cold ($T_{\rm d}\approx 14.5$ K) FIR source without an IRAS pointsource counterpart. In the Digitized Sky Survey B band it is seen as a 3\arcmin size bipolar nebulosity with an average excess surface brightness of

Eric Emsellem

In this paper, I emphasize the need for integral field spectroscopy in the study of density waves (bars, spirals, m=1 modes) in the centre of galaxies. I illustrate this by focusing on the complex and time dependent structures revealed by such techniques.

C. M. Gutierrez, M. Lopez-Corredoira, F. Prada, M. C. Eliche

We present deep broad-band R and narrow-band Halpha images of Stephan's Quintet. The observations in the R band show that the diffuse halo of the Stephan's Quintet is larger than previously thought and extends out to NGC 7320C. However, we have not found emission connecting NGC 7331 and NGC 7320 to R ~ 26.7 mag/arcsec^2 (at more than 3-sigma level),

G. Giardino, A. J. Banday, K. M. Gorski, K. Bennett

We have analysed the angular power spectra of the Parkes radio continuum and polarisation survey of the Southern galactic plane at 2.4 GHz. We have found that in the multipole range l=40-250 the angular power spectrum of the polarised intensity is well described by a power-law spectrum with fitted spectral index alpha_L = 2.37 +- 0.21. In the same multipole

E. V. Bugaev, K. V. Konishchev

Comparative analysis of different types of initial mass spectra of primordial black holes (PBHs) is carried out. It is assumed that primordial density fluctuations have power law spectrum and the spectral index is constant throughout all scales. It is shown that densities of background radiations (neutrinos, gamma-quanta) from PBH evaporations strongly depen

P. T. de Zeeuw

The GAIA space observatory was recently approved as Cornerstone 6 of ESA's science program, to be launched no later than mid-2012. It will provide a stereoscopic and kinematic census of about 10^9 stars throughout our Galaxy (and into the Local Group) complete to V=20 mag, amounting to about 1% of the Galactic stellar population. Combined with astrophysi

Sang-Hyeon Ahn

Among a number of gamma-ray bursts whose host galaxies are known, GRB971214 stands out for its high redshift(z=3.25) and the Lya emission line having a P-Cygni type profile. which is interpreted to be a direct consequence of the expanding supershell. From a simple Voigt-fitting analysis, we estimate the expansion velocity of the supershell and the neutral co

L. Magrini, R. L. M. Corradi, N. A. Walton, A. A. Zijlstra

Five planetary nebulae (PNe) have been discovered in the nearby dwarf irregular galaxy. Emission line images were obtained using the Wide Field Camera of the 2.5m Isaac Newton Telescope (INT) at La Palma (Spain). The candidate PNe were identified by their point-like appearance and relatively strong [OIII] emission-line fluxes. They are located within a galac

J-L. Atteia, M. Boer, F. Cotin, J. Couteret

The gamma-ray detector of HETE-2, called FREGATE, has been designed to detect gamma-ray bursts in the energy range [6-400] keV. Its main task is to alert the other instruments of the occurrence of a gamma-ray burst (GRB) and to provide the spectral coverage of the GRB prompt emission in hard X-rays and soft gamma-rays. FREGATE was switched on on October 16,

Roberto Casadio, Benjamin Harms, Octavian Micu

We investigate the idea that ultrahigh energy gamma-rays (E>10 TeV) can be produced when charged particles are accelerated by microscopic black holes. We begin by showing that microscopic black holes may exist as remnants of primordial black holes or as products of the collisions in the large extra dimensions scenario of high energy cosmic rays with atmosphe

Walter Dehnen

A novel code for the approximate computation of long-range forces between N mutually interacting bodies is presented. The code is based on a hierarchical tree of cubic cells and features mutual cell-cell interactions which are calculated via a Cartesian Taylor expansion in a symmetric way, such that total momentum is conserved. The code benefits from an impr

Yuichi Terashima, Naoko Iyomoto, Luis C. Ho, Andrew F. Ptak

We present the results of a systematic analysis of Fe K emission lines in low-luminosity AGNs (LLAGNs) observed with ASCA. We used a sample of LLAGNs with small intrinsic absorption to compare with luminous AGNs and accretion models. Some objects show an Fe line at 6.4 keV or 6.7 keV, and the rest of the objects show no significant Fe K emission line. We mad

Michael C. Liu, Richard Wainscoat, Eduardo L. Martin, Brian Barris

We present the discovery of a distant methane dwarf, the first from the Institute for Astronomy (IfA) Deep Survey. The object ("IfA 0230-Z1") was identified from deep optical I and z'-band imaging, being conducted as an IfA-wide collaboration using the prime-focus imager Suprime-Cam on the Subaru 8.2-m Telescope. IfA 0230-Z1 is extremely red in t

Yu. A. Kubyshin, R. Neves, R. Potting

Solutions of the Polchinski exact renormalization group equation in the scalar O(N) theory are studied. Families of regular solutions are found and their relation with fixed points of the theory is established. Special attention is devoted to the limit $N=\infty$, where many properties can be analyzed analytically.

Mohamud Mohammed

We describe Maple packages for the automatic generation of generating functions(and series expansions) for counting lattice animals(fixed polyominoes), in the two-dimensional hexagonal lattice, of bounded but arbitrary width. Our Maple packages(complete with source code) are easy-to-use and available from my website.

James E. Lidsey, Shin'ichi Nojiri, Sergei D. Odintsov

Braneworld cosmology for a domain wall embedded in the charged (Anti)-de Sitter-Schwarzschildblack hole of the five--dimensional Einstein-Gauss-Bonnet-Maxwell theory is considered. The effective Friedmann equation for the brane is derived by introducing the necessary surface counterterms required for a well-defined variational principlein the Gauss--Bonnet t

D. R. Gies, L. R. Penny, P. Mayer, H. Drechsel

We present the first orbital elements for the massive close binary, HD 101131, one of the brightest objects in the young, open cluster, IC 2944. This system is a double-lined spectroscopic binary in an elliptical orbit with a period of 9.64659 +/- 0.00012 days. It is a young system of unevolved stars (approximately 2 million years old) that are well within t

J. B. Kogut, D. K. Sinclair

We simulate lattice QCD with dynamical $u$ and $d$ quarks at finite chemical potential, $μ_I$, for the third component of isospin ($I_3$), at both zero and at finite temperature. At zero temperature there is some $μ_I$, $μ_c$ say, above which $I_3$ and parity are spontaneously broken by a charged pion condensate. This is in qualitative agreement with the pre

A. J. M. Medved

Recently, the holographic aspects of asymptotically de Sitter spacetimes have generated substantial literary interest. The plot continues in this paper, as we investigate a certain class of dilatonically deformed ``topological'' de Sitter solutions (which were introduced in hep-th/0110234). Although such solutions possess a detrimental cosmological s

V. A. Kashurnikov, N. V. Prokof'ev, B. V. Svistunov

We study (by an exact numerical scheme) the single-particle density matrix of $\sim 10^3$ ultracold atoms in an optical lattice with a parabolic confining potential. Our simulation is directly relevant to the interpretation and further development of the recent pioneering experiment by Greiner et al. In particular, we show that restructuring of the spatial d

M. G. Moore, A. Vardi

We study the photodissociation chemistry of a quantum degenerate gas of bosonic triatomic $ABC$ molecules, assuming two open rearrangement channels ($AB+C$ or $A+BC$). The equations of motion are equivalent to those of a parametric multimode laser, resulting in an exponential buildup of macroscopic mode populations. By exponentially amplifying a small differ

M. Bertolini, P. Di Vecchia, M. Frau, A. Lerda

In this note we show how the anomalies of both pure and matter coupled N=1,2 supersymmetric gauge theories describing the low energy dynamics of fractional branes on orbifolds can be derived from supergravity.

Kiwoon Choi, Hyung Do Kim, Ian-Woo Kim

We investigate the gauge coupling renormalization in orbifold field theories preserving 4-dimensional N=1 supersymmetry in the framework of 4-dimensional effective supergravity. As a concrete example, we consider the 5-dimensional Super-Yang-Mills theory on a slice of AdS_5. In our approach, one-loop gauge couplings can be determined by the loop-induced axio

G. L. Fogli, E. Lisi, A. Mirizzi, D. Montanino

Several extensions of the standard electroweak model allow new four-fermion interactions (nu_a nu_b * ff) with strength eps_ab*G_F, where (a,b) are flavor indices. We revisit their effects on flavor oscillations of massive (anti)neutrinos in supernovae, in order to achieve, in the region above the protoneutron star, an analytical treatment valid for generic

A. J. Young, A. S. Wilson, C. G. Mundell

We report sub-arcsecond X-ray imaging spectroscopy of M87 and the core of the Virgo cluster with the Chandra X-ray Observatory. The X-ray morphology shows structure on arcsecond (~100 pc) to ten arcminute (~50 kpc) scales, the most prominent feature being an "arc" running from the east, across the central region of M87 and off to the southwest. A rid

Daniel F. Litim, Jan M. Pawlowski

We study different renormalisation group flows for scale dependent effective actions, including exact and proper-time renormalisation group flows. These flows have a simple one loop structure. They differ in their dependence on the full field-dependent propagator, which is linear for exact flows. We investigate the inherent approximations of flows with a non

T. Binoth, E. W. N. Glover, P. Marquard, J. J. van der Bij

We use an n-dimensional projection method to calculate helicity amplitudes for photon-photon scattering up to the two-loop level, for massless particles inside the loop. We confirm the recent standard model results found by Bern et al using another calculational method. We further apply the method to N=1 and N=2 supersymmetric QED. As predicted by the supers

J. R. Pelaez

The SU(2) and SU(3) chiral phase transitions in a hot gas made of pions, kaons and etas are studied within the framework of Chiral Perturbation Theory. By using the meson meson scattering phase shifts in a second order virial expansion, we are able to describe the temperature dependence of the quark condensates. We have estimated the critical temperatures wh

K. Amos, S. Karataglidis, P. K. Deb

Total reaction cross sections are predicted for nucleons scattering from various nuclei. Projectile energies to 300 MeV are considered. So also are mass variations of those cross sections at selected energies. All predictions have been obtained from coordinate space optical potentials formed by full folding effective two-nucleon (NN) interactions with one bo

Sergio Caracciolo, Andrea Pelissetto

We investigate a two-dimensional classical $N$-vector model with a nonlinear interaction $(1 + \bsigma_i\cdot \bsigma_j)^p$ in the large-N limit. As observed for N=3 by Blöte {\em et al.} [Phys. Rev. Lett. {\bf 88}, 047203 (2002)], we find a first-order transition for $p>p_c$ and no finite-temperature phase transitions for $p < p_c$. For $p>p_c$, both phases

A. I. Lvovsky, J. Mlynek

We report preparation and characterization of coherent superposition states t |0> + alpha |1> of electromagnetic field by conditional measurements on a beamsplitter. The state is generated in one of the beam splitter output channels if a coherent state and a single-photon Fock state |1> are present in the two input ports and a single photon is registered in

Seungjoon Hyun, Hyeonjoon Shin

It has been shown that (2+1)-dimensional N=8 super Yang-Mills (SYM) theory with electric flux is related to (2+1)- dimensional noncommutative open string (NCOS) theory by `2-11&#39; flip. This implies that the instanton process in SYM theory, which corresponds to D0-brane exchange (M-momentum transfer) between D2-branes, is dual to the KK momentum exchange i

A. Patkos, Zs. Szep, P. Szepfalusy

The thermal evolution of the spectral densities derivable from the two-point functions of the elementary and the quadratic composite fields of the O(N) model is studied in the isosinglet channel and in the broken symmetry phase at infinite N. The results are applied with realistic parameter values to the N=4 case. They provide a reasonable description of the

Christos G. Tsagas

We present the formalism for the covariant treatment of gravitational radiation in a magnetized environment and discuss the implications of the field for gravity waves in the cosmological context. Our geometrical approach brings to the fore the tension properties of the magnetic force lines and reveals their intricate interconnection to the spatial geometry

Mario Nicodemi, Annalisa Fierro, Antonio Coniglio

We study segregation patterns in a hard sphere binary model under gravity subject to sequences of taps. We discuss the appearance of the ``Brazil nut&#39;&#39; effect (where large particles move up) and the ``reverse Brazil nut&#39;&#39; effects in the stationary states reached by ``tap&#39;&#39; dynamics. In particular, we show that the stationary state dep

W. Porod

We show that the decay gluino -> stop_1 b-quark W is important and can even be dominant in the region of parameter space where it is kinematically allowed. We discuss phenomenological implications within the Minimal Supersymmetric Standard Model and models with broken R-parity. We consider the flavour diagonal case as well as a possible mixing between squark

Rama Govindarajan

I suggest a solution to a persistent mystery in the physics of turbulent shear flows: cumulus clouds rise to towering heights, practically without entraining the ambient medium, while apparently similar turbulent jets in general lose their identity within a small distance through entrainment and mixing. From dynamical systems computations on a model chaotic

A. Fix, H. Arenhoevel

The $η$-3N-interaction is studied within the four-body Faddeev-Yakubovsky theory adopting purely separable forms for the two- and three-body subamplitudes, limiting the basic two-body interactions to s-waves only. The corresponding separable approximation for the integral kernels is obtained by using the Hilbert-Schmidt procedure. Results are presented for t

Tomohiro Matsuda

We propose a new scenario of baryon number violation in models with extra dimensions. In the true vacuum, baryon number is almost conserved due to the localization mechanism of matter fields, which suppresses the interactions between quarks and leptons. We consider several types of cosmological defects in four-dimensional spacetime that shift the center of t

Machiko Hatsuda, Kiyoshi Kamimura, Makoto Sakaguchi

The isometry algebras of the maximally supersymmetric solutions of IIB supergravity are derived by the Inonu-Wigner contractions of the super-AdS_5xS^5 algebra. The super-AdS_5xS^5 algebra allows introducing two contraction parameters; the one for the Penrose limit to the maximally supersymmetric pp-wave algebra and the AdS_5xS^5 radius for the flat limit. T

Dev P. Sinha

We present two models for the space of knots which have endpoints at fixed boundary points in a manifold with boundary, one model defined as an inverse limit of spaces of maps between configuration spaces and another which is cosimplicial. These models build on the calculus of isotopy functors and are weakly homotopy equivalent to knot spaces when the ambien

G. I. Gomero, M. J. Reboucas

Recent observations seem to indicate that we live in a universe whose spatial sections are nearly or exactly flat. Motivated by this we study the problem of observational detection of the topology of universes with flat spatial sections. We first give a complete description of the diffeomorphic classification of compact flat 3-manifolds, and derive the expre

Veronika E. Hubeny, Mukund Rangamani

We investigate some of the issues relating to the dynamical instability of general static spacetimes with horizons. Our paper will be partially pedagogical and partially exploratory in nature. After discussing the current understanding, we generalize the proposal of Gubser and Mitra, which identifies dynamical instability of black branes with local thermodyn

L. -A. Wu, M. S. Byrd, D. A. Lidar

Decoherence-induced leakage errors can couple a physical or encoded qubit to other levels, thus potentially damaging the qubit. They can therefore be very detrimental in quantum computation and require special attention. Here we present a general method for removing such errors by using simple decoupling and recoupling pulse sequences. The proposed gates are

M. Bache, P. Scotto, R. Zambrini, M. San Miguel

We investigate the spatial quantum noise properties of the one dimensional transverse pattern formation instability in intra-cavity second-harmonic generation. The Q representation of a quasi-probability distribution is implemented in terms of nonlinear stochastic Langevin equations. We study these equations through extensive numerical simulations and analyt

Alberto Barchielli, Nicola Pero

By means of quantum stochastic calculus we construct a model for an atom with two degenerate levels and stimulated by a laser and we compute its fluorescence spectrum; let us stress that, once the model for the unitary atom-field dynamics has been given, then the spectrum is computed without further approximations. If only the absorption/emission term is inc

ping-xing. chen, Cheng-zu Li

This paper try to probe the relation of distinguishing locally and distillation of entanglement. The distinguishing information (DI) and the maximal distinguishing information (MDI) of a set of pure states are defined. The interpretation of distillation of entanglement in term of information is given. The relation between the maximal distinguishing informati

A. I. Lvovsky, S. A. Babichev

Displaced Fock states of the electromagnetic field have been synthesized by overlapping the pulsed optical single-photon Fock state |1> with coherent states on a high-reflection beamsplitter and completely characterized by means of quantum homodyne tomography. The reconstruction reveals highly non-classical properties of displaced Fock states, such as negati

Tobias J. Osborne, Michael A. Nielsen

What entanglement is present in naturally occurring physical systems at thermal equilibrium? Most such systems are intractable and it is desirable to study simple but realistic systems which can be solved. An example of such a system is the 1D infinite-lattice anisotropic XY model. This model is exactly solvable using the Jordan-Wigner transform, and it is p

W. Q. Zhao

The newly developed iterative method based on Green function defined by quadratures along a single trajectory is combined with the variational method to solve the ground state quantum wave function for central potentials. As an example, the method is applied to discuss the ground state solution of Yukawa potential, using Hulthen solution as the trial functio

Jan W. Kantelhardt, Stephan A. Zschiegner, Eva Koscielny-Bunde, Armin Bunde

We develop a method for the multifractal characterization of nonstationary time series, which is based on a generalization of the detrended fluctuation analysis (DFA). We relate our multifractal DFA method to the standard partition function-based multifractal formalism, and prove that both approaches are equivalent for stationary signals with compact support

M. A. Porras, I. Gonzalo, A. Mondello

Gouy&#39;s phase of transversally limited pulses can create a strong anomalous dispersion in vacuum leading to highly superluminal and negative group velocities. As a consequence, a focusing pulse can diverge beyond the focus before converging into it. A simple experiment is proposed.

L. Sanchez-Palencia, F. -R. Carminati, M. Schiavoni, F. Renzoni

We report the first direct observation of Brillouin-like propagation modes in a dissipative periodic optical lattice. This has been done by observing, in both theoretical and experimental work, a resonant behaviour of the spatial diffusion coefficient in the direction corresponding to the propagation mode with the phase velocity of the moving intensity modul

Jean-Patrick Connerade, Andrey V Solov&#39;yov

We present a new formalism for the description of multiphoton plasmon excitation processes in jellium clusters. By using our method, we demonstrate that, in addition to dipole plasmon excitations, the multipole plasmons (quadrupole, octupole, etc) can be excited in a cluster by multiphoton absorption processes, which results in a significant difference betwe

A. Loinger

A physical consequence of a well-known Fermi&#39;s theorem: no motion of masses can generate gravitational waves.

A. V. Korol, A. V. Solov&#39;yov, W. Greiner

We investigate the influence of the spin-flip transitions on formation of the spectral distribution of the radiation emitted by tens to hundreds GeV ultrarelativistic electrons incident along crystallographic axis in a thin single crystal. Both the formalism and the numerical data are presented. The calculated spectra for 35 to 243 GeV electrons in W crystal

K. Hagino, P. -G. Reinhard, G. F. Bertsch

We develop and test efficient approximations to estimate ground state correlations associated with low- and zero-energy modes. The scheme is an extension of the generator-coordinate-method (GCM) within Gaussian overlap approximation (GOA). We show that GOA fails in non-Cartesian topologies and present a topologically correct generalization of GOA (topGOA). A

B. Pfeiffer, G. Lhersonneau, H. Gabelmann, K. -L. Kratz

Annual Report 2001, Institut fuer Kernchemie, Johannes-Gutenberg-Universitaet, Mainz, Germany

N. J. Tagg, A. Hamer, B. Sur, E. D. Earle

A calibration source employing 8Li (t_1/2 = 0.838s) has been developed for use with the Sudbury Neutrino Observatory (SNO). This source creates a spectrum of beta particles with an energy range similar to that of the SNO 8B solar neutrino signal. The source is used to test the SNO detector&#39;s energy response, position reconstruction and data reduction alg

B. K. Srivastava

A systematic analysis of the multifragmentation (MF) in fully reconstructed events from 1A GeV Au, La and Kr collisions with C has been performed. This data is used to provide a definitive test of the variable volume version of the statistical multifragmentation model (SMM). A single set of SMM parameters directly determined by the data and the semi-empirica

Ned J. Corron, Buckley A. Hopper, Shawn D. Pethel

We report experimental control of chaos in an electronic circuit at 43.9 MHz, which is the fastest chaos control reported in the literature to date. Limiter control is used to stabilize a periodic orbit in a tuned collector transistor oscillator modified to exhibit simply folded band chaos. The limiter is implemented using a transistor to enable monitoring t

Bernard J. Geurts, Darryl D. Holm

We consider so-called Leray regularization of the convective contributions. This gives rise to a subgrid parameterization which involves both explicit filtering and (approximate) inversion. The Leray model also arises from the alpha-modeling strategy derived via Kelvin&#39;s circulation theorem. We study the dynamics associated with the Leray model in a turb

G. Cicogna, M. Santoprete

We illustrate a completely analytic approach to Mel&#39;nikov theory, which is based on a suitable extension of a classical method, and which is parallel and -- at least in part -- complementary to the standard procedure. This approach can be also applied to some ``degenerate&#39;&#39; situations, as to the case of nonhyperbolic unstable points, or of critic

Paul Federbush

We present the outline of a proof for the 3-d phase transition which we hope to carry forth. At the same time this paper provides some physical understanding of the phase transition, in the flavor of relatively simple arguments from an undergraduate course. A number of directions for mathematical research, interesting in their own right, will be suggested by

Michael Forger, Cornelius Paufler, Hartmann Roemer

We present a general definition of the Poisson bracket between differential forms on the extended multiphase space appearing in the geometric formulation of first order classical field theories and, more generally, on exact multisymplectic manifolds. It is well defined for a certain class of differential forms that we propose to call Poisson forms and turns

Massimiliano Lunelli, Antonio Laface

In this paper we give a necessary and sufficient criterion for representability of a matroid over an algebraic closed field. This leads to an algorithm, based on an extension of Groebner Bases, in order to decide if a given matroid is representable over such a field.

Uwe Kaiser

We compute two-term skein modules of framed oriented links in oriented 3-manifolds. They contain the self-writhe and total linking number invariants of framed oriented links in a universal way. The relations in a natural presentation of the skein module are interpreted as monodromies in the space of immersions from circles to the 3-manifold.

Yun Gao, Naihuan Jing

We construct a vertex representation for the quantum toroidal algebra through the quantum general linear algebra. Using a new realization of the quantum general linear algebra we construct vertex operators for root vectors on the basic representation of the affine Lie algebra $gl_n$ and show that the simple generators give rise a realization of the quantum t

A. Asselah, F. Castell

We prove a full large deviations principle in large time, for a diffusion process with random drift V, which is a centered Gaussian shear flow random field. The large deviations principle is established in a ``quenched&#39;&#39; setting, i.e. is valid almost surely in the randomness of V.

Vladimir Kanovei, Michael Reeken

We consider reducibility of equivalence relations (ERs, for brevity), in a nonstandard domain, in terms of the Borel reducibility and the countably determined (CD, for brevity) reducibility. This reveals phenomena partially analogous to those discovered in descriptive set theory. The Borel reducibility structure of Borel sets and (partially) CD reducibility

J. M. Ancochea, R. Campoamor

We determine the solvable complete Lie algebras whose nilradical is isomorphic to a filiform Lie algebra. Moreover we show that for any positive integer $n$ there exists a solvable complete Lie algebras whose second cohomology group with values in the adjoint module has dimension at least $n$.

Kai Behrend, Anne O&#39;Halloran

We describe an approach to calculating the cohomology rings of stable map spaces. The method we use is due to Akildiz-Carrell and employs a C^*-action and a vector field which is equivariant with respect to this C^*-action. We give an explicit description of the big Bialynicky-Birula cell of the C^*-action on Mbar_00(P^n,d) as a vector bundle on Mbar_0d. Thi

Ilya Kapovich, Nadia Benakli

We survey the known results regarding the boundaries of word-hyperbolic groups.

Ilya Kapovich, Alexei Myasnikov

We re-cast in a more combinatorial and computational form the foldings approach of John Stallings and pursue a detailed study of the subgroup structure of free groups. In particular, we introduce the notions of an &#34;algebraic&#34; and a &#34;free&#34; extension for subgroups of free groups and apply these notions to obtain a number of algebraic and algori

J. Colliander, M. Keel, G. Staffilani, H. Takaoka

In this paper we prove that the 1D Schrödinger equation with derivative in the nonlinear term is globally well-posed in $H^{s}$, for $s>\frac12$ for data small in $L^{2}$. To understand the strength of this result one should recall that for $s<\frac12$ the Cauchy problem is ill-posed, in the sense that uniform continuity with respect to the initial data fail

D. Baleanu, Y. Guler

The Hamilton-Jacobi formalism was applied to quantize the front-form Schwinger model. The importance of the surface term is discussed in detail. The BRST-anti-BRST symmetry was analyzed within Hamilton-Jacobi formalism.

K. Van Acoleyen, J. A. Gracey, H. Verschelde

We probe the U(N) chiral Gross-Neveu model with a source-term $JłΨΨ$. We find an expression for the renormalization scheme and scale invariant source $\hat{J}$, as a function of the generated mass gap. The expansion of this function is organized in such a way that all scheme and scale dependence is reduced to one single parameter $d$. We obtain a non-perturb

Edmond Iancu, Andrei Leonidov, Larry McLerran

In these lectures, we develop the theory of the Colour Glass Condensate. This is the matter made of gluons in the high density environment characteristic of deep inelastic scattering or hadron-hadron collisions at very high energy. The lectures are self contained and comprehensive. They start with a phenomenological introduction, develop the theory of classi

Antonio O. Bouzas, Ruben Flores-Mendieta

We give a complete analytical computation of three-point one-loop integrals with one heavy propagator, up to the third tensor rank, for arbitrary values of external momenta and masses.

Steven R. Elliott, Petr Vogel

The motivation, present status, and future plans of the search for the neutrinoless double beta decay are reviewed. It is argued that, motivated by the recent observations of neutrino oscillations, there is a reasonable hope that neutrinoless double beta decay corresponding to the neutrino mass scale suggested by oscillations, <m_ν> of about 50 meV, actually

Biswajoy Brahmachari, Ernest Ma

If the electron neutrino has an effective nonzero Majorana mass, then neutrinoless double beta decay will occur. However, the latter is possible also with a negligible neutrino mass. We show how this may happen in a simple model of scalar diquarks and dileptons. This possibility allows neutrino masses to be small and hierarchical, without conflicting with th

I. Tsukerman

This note presents an overview of general-purpose and specific Monte-Carlo event generators used in the simulation of the CERN - CHORUS experiment, aiming to search for $ν_μ \to ν_τ$ oscillations and charm particle decays in an emulsion target.

J. P. Ma

Recently CLEO has studied the radiative decay of $Υ$ into $η&#39;$ and an upper limit for the decay has been determined. Confronting with this upper limit,most of theoretical predictions for the decay fails. After briefly reviewing these predictions we re-examine the decay by separating nonperturbative effect related to the quarkonium and that related to $η&

R. D. Young, D. B. Leinweber, A. W. Thomas, S. V. Wright

We extend a technique for the chiral extrapolation of hadron masses calculated with dynamical fermions to those generated by quenched simulations. The method ensures the correct leading and next-to-leading non-analytic behaviour for either QCD or quenched QCD in the chiral limit, as well as the correct large quark mass behaviour. We find that the primary dif

D. V. Ahluwalia

In this talk I review a series of recent conceptual developments at the interface of the quantum and gravitational realms. Wherever possible, I comment on the possibility to probe the interface experimentally. It is concluded that the underlying spacetime for a quantum theory of gravity must be non-commutative, that wave-particle duality suffers significant

Graham Brightwell, H. Fay Dowker, Joe Henson, Raquel S. Garcia

Identifying an appropriate set of ``observables&#39;&#39; is a nontrivial task for most approaches to quantum gravity. We describe how it may be accomplished in the context of a recently proposed family of stochastic (but classical) dynamical laws for causal sets. The underlying idea should work equally well in the quantum case.

Harald P. Pfeiffer, Lawrence E. Kidder, Mark A. Scheel, Saul A. Teukolsky

We present a new solver for coupled nonlinear elliptic partial differential equations (PDEs). The solver is based on pseudo-spectral collocation with domain decomposition and can handle one- to three-dimensional problems. It has three distinct features. First, the combined problem of solving the PDE, satisfying the boundary conditions, and matching between d

Robert J. Bursill, W. Barford

A density matrix renormalisation group scheme is developed, allowing for the first time essentially exact numerical solutions for the important excited states of a realistic semi-empirical model for oligo-phenylenes. By monitoring the evolution of the energies with chain length and comparing them to the experimental absorption peaks of oligomers and thin fil

Avik W. Ghosh, Ferdows Zahid, Prashant S. Damle, Supriyo Datta

We investigate the origin of asymmetry in the measured current-voltage (I-V) characteristics of molecules with no inherent spatial asymmetry. We establish that such molecules can exhibit asymmetric I-V characteristics due to unequal coupling with the contacts. In contrast with spatially asymmetric molecules, conduction takes place through essentially the sam

R. G. Hennig, K. F. Kelton, A. E. Carlsson, C. L. Henley

The atomic structure of the icosahedral Ti-Zr-Ni quasicrystal is determined by invoking similarities to periodic crystalline phases, diffraction data and the results from ab initio calculations. The structure is modeled by decorations of the canonical cell tiling geometry. The initial decoration model is based on the structure of the Frank-Kasper phase W-TiZ