April 2002 arXiv papers — page 9

A. Constandache, Ashok Das, Ziemowit Popowicz

We generalize the Benney lattice and show that the new system of equations can be reduced to a generalized Chaplygin gas as well as the heavenly equation. We construct two infinite sets of conserved charges and show that one of the sets can be obtained from the Lax function. The conserved densities are related to Legendre polynomials and we present closed fo

A. Alonso Izquierdo, M. A. Gonzalez Leon, J. Mateos Guilarte

We identify the kinks of a deformed O(3) linear Sigma model as the solutions of a set of first-order systems of equations; the above model is a generalization of the MSTB model with a three-component scalar field. Taking into account certain kink energy sum rules we show that the variety of kinks has the structure of a moduli space that can be compactified i

Fabio Enrique Brochero, Carmen Rosa Giraldo

The Zorn's Algebra ZZ(R) has a multiplicative function called determinant with properties similar to the usual one. The set of elements in ZZ(R) with determinant 1 is a Moufang loop that we will denote by \GA. In our main result we prove that if R is a Dedekind algebraic number domain that contains an infinite order unit, each finite index subloop L, suc

Vyacheslav S. Rychkov

This thesis is devoted to asymptotic norm estimates for oscillatory integral operators acting on the L^2 space of functions of one real variable. The operators in question have compact support and an oscillatory kernel of the form exp(i Lambda S(x,y)), where S(x,y) is a smooth real phase function, and Lambda is a large real number. I study how the norm of th

David Gamarnik

Our model is a constrained homogeneous random walk in a nonnegative orthant Z_+^d. The convergence to stationarity for such a random walk can often be checked by constructing a Lyapunov function. The same Lyapunov function can also be used for computing approximately the stationary distribution of this random walk, using methods developed by Meyn and Tweedie

Stefan Bauer

The main theorem describes the behaviour of the stable cohomotopy invariant defined in the first article (joint with M. Furuta) in this series of two under the operation of taking connected sums of four-manifolds: The invariant of a connected sum is the smash product (in the sense of equivariant spectra) of the invariants of the respective summands. This pro

Vitor Araujo

Adding small random parametric noise to an arc of diffeomophisms of a manifold of dimension 3, generically unfolding a codimension one quadratic homoclinic tangency q associated to a sectionally dissipative saddle fixed point p, we obtain not more than a finite number of physical probability measures, whose ergodic basins cover the orbits which are recurrent

Matthieu Willems

The aim of this text is to give an explicit formula for the restriction to fixed points of a basis of the equivariant K-theory of the flag varieties and of the Bott-Samelson varieties.

I. Heckenberger, S. Kolb

The dual coalgebra of Podleś' quantum sphere O_q(S^2_c) is determined explicitly. This result is used to classify all finite dimensional covariant first order differential calculi over O_q(S^2_c) for all but exceptional values of the parameter c.

P. Chigansky, R. Liptser

We give elementary proof of a stability result concerning an exponential asymptotic ($t\to\infty$) for filtering estimates generated by wrongly initialized Wonham filter. This proof is based on new exponential bound having independent interest.

Osamu Fujino

The main purpose of this paper is to prove the Iitaka conjecture $C_{n,m}$ on the assumption that the sufficiently general fibers have maximal Albanese dimension.

Ch. Birkenhake, H. Lange

In a previous paper we showed that for every polarization on an abelian variety there is a dual polarization on the dual abelian variety. In this note we extend this notion of duality to families of polarized abelian varieties. As a main consequence we obtain an involution on the set of moduli spaces of polarized abelian varieties of dimension $g$. In partic

Maria Lucia Fania, Emilia Mezzetti

We study the Hilbert scheme of Palatini threefolds X in P^5. We prove that such a scheme has an irreducible component containing X which is birational to the Grassmannian G(3,14) and we determine the exceptional locus of the birational map.

Hugh Thomas

Let I be the toric ideal defined by a 2 x n matrix of integers, A = ((1 1 ... 1)(a_1 a_2 ... a_n)) with a_1<a_2<...<a_n. We give a combinatorial proof that I is generated by elements of degree at most the sum of the two largest differences a_i - a_(i-1). The novelty is in the method of proof: the result has already been shown by L&#39;vovsky using cohomologi

C H Barton, A Sudbery

This paper is concerned with the description of exceptional simple Lie algebras as octonionic analogues of the classical matrix Lie algebras. We review the Tits-Freudenthal construction of the magic square, which includes the exceptional Lie algebras as the octonionic case of a construction in terms of a Jordan algebra of hermitian 3x3 matrices (Tits) or var

Bob Coecke

In arXiv: math.LO/0011208 we proposed the {\sl intuitionistic or disjunctive representation of quantum logic}, i.e., a representation of the property lattice of physical systems as a complete Heyting algebra of logical propositions on these properties, where this complete Heyting algebra goes equipped with an additional operation, the {\sl operational resolu

Bob Coecke

In their seminal paper Birkhoff and von Neumann revealed the following dilemma: &#34;... whereas for logicians the orthocomplementation properties of negation were the ones least able to withstand a critical analysis, the study of mechanics points to the distributive identities as the weakest link in the algebra of logic.&#34; In this paper we eliminate this

A. Gorsky, I. I. Kogan, G. Korchemsky

We discuss the stringy properties of high-energy QCD using its hidden integrability in the Regge limit and on the light-cone. It is shown that multi-colour QCD in the Regge limit belongs to the same universality class as superconformal $\cal{N}$=2 SUSY YM with $N_f=2N_c$ at the strong coupling orbifold point. The analogy with integrable structure governing t

Carlos Castro

A novel approach that does not rely on supersymmetry, nor in the AdS/CFT correspondence, to evaluate the Wilson loops asociated with a gauge theory of area-preserving diffeomorphisms in terms of pure string degrees of freedoms is presented. It is based on the Guendelman-Nissimov-Pacheva formulation of composite antisymmetric tensor field theories of volume-p

Rafael I. Nepomechie

We construct boundary quantum group generators which, through linear intertwining relations, determine nondiagonal solutions of the boundary Yang-Baxter equation for the cases A^1_{n-1} and A^2_2.

J. M. Isidro

Looking for a quantum-mechanical implementation of duality, we formulate a relation between coherent states and complex-differentiable structures on classical phase space ${\cal C}$. A necessary and sufficient condition for the existence of locally-defined coherent states is the existence of an almost complex structure on ${\cal C}$. A necessary and sufficie

N. D. Hari Dass, V. Soni

We consider an extended linear $σ$ model in which the fermions are quarks and are coupled to gluons. Equivalently, this is QCD extended by coupling the quarks to a colour singlet chiral multiplet of ($ σ, \vec π$) fields. This theory has a phase governed by a UV fixed point where all couplings are AF (asymptotically free). This implies that the scalars are e

Zhou Bang-Rong

Discrete symmetry breaking and possible restoration at finite temperature $T$ are analysed in 2D Gross-Neveu model by the real-time thermal field theory in the fermion bubble approximation. The dynamical fermion mass $m$ is proven to be scale-independent and this fact indicates the equivalence between the fermion bubble diagram approximation and the mean fie

Tzihong Chiueh

In the Seiberg-Witten limit, the low-energy dynamics of N weakly coupled identical open strings on a D3-brane can behave as two-dimensional incompressible hydrodynamics. Classical vortices are frozen in the fluid and described by an action expressed in terms of two canonical conjugate fields, which can be taken as the new space coordinate. The noncommutative

A. Marshakov

We consider the associativity or Witten-Dijkgraaf-Verlinde-Verlinde (WDVV) equations and discuss one of the most relevant for non-perturbative physics class of their solutions based on existence of the residue formulas. It is demonstrated for this case that the proof of associativity equations is reduced to the problem of solving system of algebraic linear e

A. S. Safir

We predict contributions of higher $K$-resonances to the radiative rare decays $b\to sγ$, in the framework of the QCD sum rules on the light cone (LCSR). Our calculations are restricted to the leading twist-two operators for $K^*(892)$ and to the asymptotic wave function for the other $K^{**}$-mesons. Using experimental data on the semileptonic $τ\to K^{**}ν

A. P. Balachandran, S. Digal

Non-abelian (NA) topological string defects exist in QCD with the spontaneous chiral symmetry breaking $U(N_f)_L \times U(N_f)_R \to U(N_f)_V$. Anomaly effects lead to domain walls connected to these strings. In the framework of linear sigma model we find the configuration of these defects. Also we show that in this model metastable CP violating vacuua exist

Winston Roberts

A pole model for the form factors describing heavy to light meson transitions is constructed, and the results compared with the predictions of the heavy quark effective theory (HQET). While most of the HQET-predicted relationships among form factors hold at the maximum value of $q^2$, many are violated, suggesting that the simplest version of the pole model

V. P. Nomokonov, M. G. Sapozhnikov

The OZI rule have been tested in a number of experiments in a wide interval of energies. It was found that the rule is fulfilled well, within few percent of accuracy. The results of experiments with stopped antiprotons at LEAR (CERN), where unexpected large violation (by a factor 3-70) of the OZI rule was found, were quite surprising. Later experiments found

Subhendra Mohanty, B. Mukhopadhyay, A. R. Prasanna

During inflation primordial quantum fluctuations of the spacetime metric become classical and there is a spontaneous CPT violation by the spin connection coupling terms of the metric with fermions. The energy levels of the left and the right chirality neutrinos is split which gives rise to a net lepton asymmetry at equilibrium. A net baryon asymmetry of the

K. Matsuda, T. Kikuchi, T. Fukuyama, H. Nishiura

We examine the constraints from the recent HEIDELBERG-MOSCOW double beta decay experiment. It leads us to the almost degenerate or inverse hierarchy neutrino mass scenario. In this scenario, we obtain possible upper bounds for the Majorana CP violating phase in the lepton sector by incorporating the data from the neutrino oscillation, the single beta decay e

James J. Kelly

A Fourier-Bessel analysis is used to fit charge and magnetization densities to data for the nucleon Sachs form factors. The neutron and proton magnetization densities are very similar, but the proton charge density is significantly softer. A useful measurement of the neutron charge density is obtained, although the relative uncertainty in the interior will r

M. Faber, J. Greensite, S. Olejnik

We review arguments for center dominance in center gauges where vortex locations are correctly identified. We introduce an appealing interpretation of the maximal center gauge, discuss problems with Gribov copies, and a cure to the problems through the direct Laplacian center gauge. We study correlations between direct and indirect Laplacian center gauges.

J. W. Nam, Y. I. Choi, D. W. Kim, J. H . Kim

We have developed a detailed Monte Carlo simulation program for the Belle TOF system. Based on GEANT simulation, it takes account of all physics processes in the TOF scintillation counters and readout electronics. The simulation reproduces very well the performance of the Belle TOF system, including the dE/dx response, the time walk effect, the time resoluti

SLAC E155 Collaboration, P. L. Anthony, R. G. Arnold, T. Averett

We have measured the spin structure functions g2p and g2d and the virtual photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 0.7 < Q^2 < 20 GeV^2 by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH3 and 6LiD targets. Our measured g2 approximately follows the twist-2 Wandzura-Wilczek calcul

N. Yu. Savchenko, S. V. Savchenko, A. V. Toporensky

We investigate the dynamics of a Bianchi I brane Universe in the presence of a nonlocal anisotropic stress ${\cal P}_{μν}$ proportional to a &#34;dark energy&#34; ${\cal U}$. Using this ansatz for the case ${\cal U} > 0$ we prove that if a matter on a brane satisfies the equation of state $p=(γ-1)ρ$ with $γ\le 4/3$ then all such models isotropize. For $γ> 4/

G. S. Asanov

We undertake to show how the relativistic Finslerian Metric Function (FMF) should arise under uni-directional violation of spatial isotropy, keeping the condition that the indicatrix (mass-shell) is a space of constant negative curvature. By evaluating respective Finslerian tetrads, and treating them consistently as the bases of inertial reference frame (RF)

B. L. Hu

We describe a kinetic theory approach to quantum gravity -- by which we mean a theory of the microscopic structure of spacetime, not a theory obtained by quantizing general relativity. A figurative conception of this program is like building a ladder with two knotted poles: quantum matter field on the right and spacetime on the left. Each rung connecting the

Rajkumar Buyya

Computational Grids, emerging as an infrastructure for next generation computing, enable the sharing, selection, and aggregation of geographically distributed resources for solving large-scale problems in science, engineering, and commerce. As the resources in the Grid are heterogeneous and geographically distributed with varying availability and a variety o

Naren Ramakrishnan, Chris Bailey-Kellogg

Data mining has traditionally focused on the task of drawing inferences from large datasets. However, many scientific and engineering domains, such as fluid dynamics and aircraft design, are characterized by scarce data, due to the expense and complexity of associated experiments and simulations. In such data-scarce domains, it is advantageous to focus the d

Ron Fagin, Amnon Lotem, Moni Naor

Let D be a database of N objects where each object has m fields. The objects are given in m sorted lists (where the ith list is sorted according to the ith field). Our goal is to find the top k objects according to a monotone aggregation function t, while minimizing access to the lists. The problem arises in several contexts. In particular Fagin (JCSS 1999)

Aleksandar Ignjatovic, Arun Sharma

In this paper we demonstrate that the class of basic feasible functionals has recursion theoretic properties which naturally generalize the corresponding properties of the class of feasible functions. We also improve the Kapron - Cook result on mashine representation of basic feasible functionals. Our proofs are based on essential applications of logic. We i

Patrick Byrne, Eugene H. Kim, Catherine Kallin

Recent conductivity measurements performed on the hole-doped two-leg ladder material $\mathrm{Sr_{14-x}Ca_xCu_{24}O_{41}}$ reveal an approximately linear power law regime in the c-axis DC resistivity as a function of temperature for $x=11$. In this work, we employ a bosonic model to argue that umklapp processes are responsible for this feature and for the hi

P. Prinsen, P. B. Warren, M. A. J. Michels

The evolution of the contact zone between pure surfactant and solvent has been studied by mesoscale simulation. It is found that mesophase formation becomes diffusion controlled and follows the equilibrium phase diagram adiabatically almost as soon as individual mesophases can be identified, corresponding to times in real systems of order 10 microseconds.

L. V. Butov, A. C. Gossard, D. S. Chemla

Macroscopically ordered arrays of vortices in quantum liquids, such as superconductors, He-II, and atom Bose-Einstein Condensates (BEC), demonstrate macroscopic coherence in flowing superfluids [1-4]. Despite of the rich variety of systems where quantum liquids reveal macroscopic ordering, experimental observation of a macroscopically ordered electronic stat

Jens Kortus, Tunna Baruah, N. Bernstein, Mark R. Pederson

We report the electronic structure and magnetic ordering of the single molecule magnet [Mn$_{10}$O$_{4}$(2,2&#39;-biphenoxide)$_{4}$Br$_{12}$]$^{4-}$ based on first-principles all-electron density-functional calculations. We find that two of the ten core Mn atoms are coupled antiferromagnetically to the remaining eight, resulting in a ferrimagnetic ground st

A. A. Zvyagin

Here we clarify few important issues raised in the recent cond-mat/0204241.

S. Fratini, F. Guinea

The low temperature dependence of the spin and charge susceptibilities of an anisotropic electron system in two dimensions is analyzed. It is shown that the presence of inflection points at the Fermi surface leads, generically, to a $ T \log T $ dependence, and a more singular behavior, $χ\sim T ^{3/4} \log T$, is also possible. Applications to quasi two-dim

Amandine Aftalion, Robert L. Jerrard

For a Bose-Einstein condensate placed in a rotating trap, we study the simplified energy of a vortex line derived in Aftalion-Riviere Phys. Rev. A 64, 043611 (2001) in order to determine the shape of the vortex line according to the rotational velocity and the elongation of the condensate. The energy reflects the competition between the length of the vortex

Andrea Rocco, Ute Ebert, Willem Hundsdorfer

We recently have shown that a negative streamer in a sufficiently high homogeneous field can branch spontaneously due to a Laplacian instability, rather than approach a stationary mode of propagation with fixed radius. In our previous simulations, the streamer started from a wide initial ionization seed on the cathode. We here demonstrate in improved simulat

Guy Vinograd, Moshe Schwartz

We consider the structure factor of a system of colloidal particles immersed in a host liquid. Each particle is assumed to be affected by forces due to other particles, a drag force proportional to the velocity of the particle relative to the local velocity of the fluid and a fluctuating random noise. The effect of the particles on the velocity field of the

J. Wang, Y. Bugoslavsky, A. Berenov, L. Cowey

Bulk samples of MgB2 were prepared with 5, 10, and 15% wt.% Y2O3 nanoparticles added using a simple solid-state reaction route. Transmission electron microscopy (TEM) showed a fine nanostructure consisting of ~3-5 nm YB4 nanoparticles embedded within MgB2 grains of ~400 nm size. Compared to an undoped control sample, an improvement in the in-field critical c

Frithjof B Anders

The two-channel Anderson lattice model which has $SU(2)\otimes SU(2)$ symmetry is of relevance to understanding of the magnetic, quadrupolar and superconducting phases in U$_{1-x}$Th$_x$Be$_{13}$ or Pr base skutterudite compounds such as PrFe$_4$P$_{12}$ or PrOs$_4$Sb$_{12}$. Possible unconventional superconducting phases of the model are explored. They are

Vipin Srivastava, Raishma Krishnan

The fundamental problem of phase saturation of electrons in a disordered mesoscopic system at very low temperatures is addressed. The disorder in the medium has both static and dynamic components, the latter being in the form of two-level systems (TLSs), which becomes just about the only source of inelastic scattering in the limit $T\to 0$. We propose that b

Masashi Torikai, Takashi Odagaki

The harmonic Fibonacci chain, which is one of a quasiperiodic chain constructed with a recursion relation, has a singular continuous frequency-spectrum and critical eigenstates. The validity of the Fourier law is examined for the harmonic Fibonacci chain with stochastic heat baths at both ends by investigating the system size N dependence of the heat current

A. Fledderjohann, K. -H. Muetter

Configurations of singlets and triplets on the SSL have been proposed in the literature as variational ground states of the Shastry-Sutherland model at fixed magnetization M. We prove, that isolated triplet excitations on the SSL are unstable if the coupling alpha falls below a critical value alpha_c=2.0 (approx.). The instability should be visible in the co

Barbara Drossel, Mehran Kardar

We study the fluctuations of particles sliding on a stochastically growing surface. This problem can be mapped to motion of passive scalars in a randomly stirred Burger&#39;s flow. Renormalization group studies, simulations, and scaling arguments in one dimension, suggest a rich set of phenomena: If particles slide with the avalanche of growth sites (advecti

Ulrich Hohenester, Filippo Troiani, Elisa Molinari

Using a master-equation approach for the description of coherent and incoherent dynamics in `artificial atoms and molecules&#39;, we present a theoretical analysis of situations where intense laser fields lead to pronounced renormalizations of carrier states. Such enhanced light-matter interactions allow for the solid-state implementation of effects hitherto

Mikhail Limonov, Sergey Lee, Setsuko Tajima, Akio Yamanaka

Resonant Raman scattering below Tc has been discovered in several Bi-, Hg-, Tl-based high-Tc superconductors with three or four CuO2-layers. For Bi2Si2Ca2Cu3O10+d, we found an unexpected crossover of the pair-breaking peak in the A1g-spectrum from a broad bump at hw = 6kBTc for Eexc = 2.54eV to a sharp peak at hw = 8kBTc for Eexc = 2.18eV, together with a st

Kentaro Nomura, Daijiro Yoshioka

The natures of the ground state in a $ν_{\rm T}=1$ bilayer quantum Hall system at a variety of layer spacing are investigated. At small layer separations the system exhibits spontaneous interlayer phase coherence. It is claimed that the Halperin&#39;s (1,1,1) state is not relevant in the incompressible regime near the incompressible to compressible transitio

Nizam A. Taylanov

The propagation of a nonlinear stationary thermomagnetic wave in superconducting media is qualitatively analyzed in view of the effect of an external magnetic field. The velocity and the thickness of the wave front are estimated. It is demonstrated that the inclusion of an external magnetic field affects the thermomagnetic wave profile only slightly.

Nizam A. Taylanov

The problem of the stability of a nonlinear thermomagnetic wave with respect to small thermal and electromagnetic perturbations in hard superconductors was studied. It is shown that spatially bounded solutions may correspond only to the perturbations decaying with time, which implies stability of the nonlinear thermomagnetic wave.

Jun Liu, A. Zaslavsky, L. B. Freund

We have experimentally investigated the hole states in a gated vertical strained Si/SiGe quantum dot. We demonstrate the inhomogeneous strain relaxation on the lateral surface creates a ring-like potential near the perimeter of the dot, which can confine hole states exhibiting quantum ring characteristics. The magnetotunneling spectroscopy exhibits the predi

Bradley A. Foreman

A method for incorporating electromagnetic fields into empirical tight-binding theory is derived from the principle of local gauge symmetry. Gauge invariance is shown to be incompatible with empirical tight-binding theory unless a representation exists in which the coordinate operator is diagonal. The present approach takes this basis as fundamental and uses

J. Matsuno, A. Fujimori, Y. Takeda, M. Takano

We have studied the chemical potential shift in La(1-x)Sr(x)MnO(3) as a function of doped hole concentration by core-level x-ray photoemission. The shift is monotonous, which means that there is no electronic phase separation on a macroscopic scale, whereas it is consistent with the nano-meter scale cluster formation induced by chemical disorder. Comparison

Guo-meng Zhao, Vidula Kirtikar, Donald E. Morris

We have studied the oxygen-isotope effects on T_{c} and in-plane penetration depth λ_{ab}(0) in an optimally doped 3-layer cuprate Bi_{1.6}Pb_{0.4}Sr_{2}Ca_{2}Cu_{3}O_{10+y} (T_{c} \sim 107 K). We find a small oxygen-isotope effect on T_{c} (α_{O} = 0.019), and a substantial effect on λ_{ab} (0) (Δλ_{ab} (0)/λ_{ab} (0) = 2.5\pm0.5%). The present results alon

Guo-meng Zhao, H. Keller, K. Conder

We review various isotope effects in the high-T_c cuprate superconductors to assess the role of the electron-phonon interaction in the basic physics of these materials. Of particular interest are the unconventional isotope effects on the supercarrier mass, on the charge-stripe formation temperature, on the pseudogap formation temperature, on the EPR linewidt

Guo-meng Zhao

we identify the intrinsic bulk pairing symmetry for both electron and hole-doped cuprates from the existing bulk- and nearly bulk-sensitive experimental results such as magnetic penetration depth, Raman scattering, single-particle tunneling, Andreev reflection, nonlinear Meissner effect, neutron scattering, thermal conductivity, specific heat, and angle-reso

O. Tchernyshyov, S. L. Sondhi

Much insight into the low temperature properties of quantum magnets has been gained by generalizing them to symmetry groups of order N, and then studying the large N limit. In this paper we consider an unusual aspect of their finite temperature behavior--their exhibiting a phase transition between a perfectly paramagetic state and a paramagnetic state with a

Hyun-Tak Kim

This is a full-paper of the paper(Physica C341-348, 259(2000)) published previously. The effective charge and the Coulomb energy are justified by means of measurement. Theoretical calculations of the effective mass depending on band filling are also given by Gutzwiller&#39;s variational calculations. On the basis of the concept of measurement, the effective

A. Tanner, A. M. Ghez, M. Morris, E. E. Becklin

We present diffraction-limited 2-25 micron images obtained with the W. M. Keck 10-m telescopes that spatially resolve the cool source, IRS 21, one of a small group of enigmatic objects in the central parsec of our Galaxy that have eluded classification. Modeled as a Gaussian, the azimuthally-averaged intensity profile of IRS 21 has a half-width half-maximum

Peter M. Woods

Soft Gamma Repeaters (SGRs) undergo changes in their pulse properties and persistent emission during episodes of intense burst activity. SGR 1900+14 has undergone large flux increases following recent burst activity. Both SGR 1900+14 and SGR 1806-20 have shown significant changes in their pulse profile and spin-down rates during the last several years. The p

T. P. Li, Y. Muraki

The interpretation of Fourier spectra in the time domain is critically examined. Power density spectra defined and calculated in the time domain are compared with Fourier spectra in the frequency domain for three different types of variability: periodic signals, Markov processes and random shots. The power density spectra for a sample of neutron stars and bl

R. Nesci, E. Massaro, M. Maesano, F. Montagni

The optical (BVRI) and radio (8.4 GHz) light curves of S5 1803+784 on a time span of nearly 6 years are presented and discussed. The optical light curve showed an overall variation greater than 3 mag, and the largest changes occured in three strong flares. No periodicity was found in the light curve on time scales up to a year. The variability in the radio b

A. Hallgren

The data from the first year of operation of the 10-string, AMANDA-B10, high-energy neutrino detector array at the South Pole have been analyzed and searched for evidence of neutrinos from cosmic sources. Differently optimized selection criteria have been used and limits on the flux of high-energy neutrinos from a variety of objects have been derived

N. J. Schurch, T. P. Roberts, R. S. Warwick

We utilize the complimentary capabilities of XMM-Newton and Chandra, to conduct a detailed imaging and spectral study of the nearby galaxy NGC 4945 focussing on its nucleus and immediate surroundings (within ~1 kpc of the nucleus). A complex morphology is revealed including a predominantly hard, but partially resolved, nuclear source plus a spectrally soft,

Melvyn B. Davies, Andrew King, Stephan Rosswog, Graham Wynn

We suggest that the collapsing core of a massive rotating star may fragment to produce two or more compact objects. Their coalescence under gravitational radiation gives the resulting black hole or neutron star a significant kick velocity, which may explain those observed in pulsars. A gamma-ray burst can result only when this kick is small. Thus only a smal

L. H. Ford, N. F. Svaiter

The quantization of the scalar and electromagnetic fields in the presence of a parabolic mirror is further developed in the context of a geometric optics approximation. We extend results in a previous paper to more general geometries, and also correct an error in one section of that paper. We calculate the mean squared scalar and electric fields near the foc

V. Sopova, L. H. Ford

We compute the expectations of the squares of the electric and magnetic fields in the vacuum region outside a half-space filled with a uniform dispersive dielectric. We find a positive energy density of the electromagnetic field which diverges at the interface despite the inclusion of dispersion in the calculation. We also investigate the mean squared fields

V. Gomes Lima, V. Silva Santos, R. de Lima Rodrigues

Static field classical configurations in (1+1)-dimensions for new non-linear potential models are investigated from an isospectral potential class and the concept of bosonic zero- mode solution. One of the models here considered has a static non-topological configuration with a single vacuum state that breaks supersymmetry.

Mohsen Alishahiha, Mohammad M. Sheikh-Jabbari

Based on the observation that $AdS_5\times S^5/Z_k$ orbifolds have a maximal supersymmetric PP-wave limit, the description of strings in PP-waves in terms of ${\cal N}=2$ quiver gauge theories is presented. We consider two different, small and large $k$, cases and show that the operators in the gauge theory which correspond to stringy excitations are labelle

D. S. Kuzmenko

The static three-quark potential in arbitrary configuration of quarks is calculated analytically. It is shown to be in a full agreement with the precise numerical simulations in lattice QCD. The results of the work have important application in nuclear physics, as they allow to perform accurate analytic calculations of spectra of the baryons.

Saber Bagherinezhad, Vahid Karimipour

We introduce a protocol for quantum secret sharing based on reusable entangled states. The entangled state between the sender and the receiver acts only as a carrier to which data bits are entangled by the sender and disentangled from it by the receivers, all by local actions of simple gates. We also show that the interception by Eve or the cheating of one o

Ginestra Bianconi

The mean field solution of the Ising model on a Barabasi-Albert scale-free network with ferromagnetic coupling between linked spins is presented. The critical temperature $T_c$ for the ferromagnetic to paramagnetic phase transition (Curie temperature) is infinite and the effective critical temperature for a finite size system increases as the logarithm of th

SNO Collaboration

Observations of neutral current neutrino interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current, elastic scattering, and charged current reactions and assuming the standard 8B shape, the electron-neutrino component of the 8B solar flux is 1.76 +/-0.05(stat.)+/-0.09(syst.) x10^6/(cm^2 s), for a kinetic energy thr

K. S. Babu, Ts. Enkhbat, I. Gogoladze

In N = 1 super Yang-Mills theories, under certain conditions satisfied by the spectrum and the Yukawa couplings, the beta functions will vanish to all orders in perturbation theory. We address the generation of realistic quark mixing angles and masses in such finite Grand Unified Theories. Working in the context of finite SUSY SU(5), we present several examp

H. Bechmann-Pasquinucci, N. Gisin

We present a generalized Bell inequality for two entangled quNits. On one quNit the choice is between two standard von Neumann measurements, whereas for the other quNit there are $N^2$ different binary measurements. These binary measurements are related to the intermediate states known from eavesdropping in quantum cryptography. The maximum violation by $\sq

P. Zhang, X. F. Liu, C. P. Sun

In a close form without referring the time-dependent Hamiltonian to the total system, a consistent approach for quantum measurement is proposed based on Zurek&#39;s triple model of quantum decoherence [W.Zurek, Phys. Rev. D 24, 1516 (1981)]. An exactly-solvable model based on the intracavity system is dealt with in details to demonstrate the central idea in

Andrew E. Chubykalo, Vladimir Onoochin

In this work we revisit the process of constructing wave equations for the scalar and vector potentials of an electromagnetic field, and show that a wave equation with an arbitrary velocity (including a velocity higher than the velocity of light in vacuum) for the scalar potential exists in the framework of classical electrodynamics. Some consequences of thi

W. J. Briscoe, B. L. Berman, R. W. C. Carter, K. S. Dhuga

We have measured the elastic-scattering ratios of normalized yields for charged pions from 3H and 3He in the backward hemisphere. At 180 MeV, we completed the angular distribution begun with our earlier measurements, adding six data points in the angular range of 119 deg to 169 deg in the pi-nucleus center of mass. We also measured an excitation function wit

B. Toen

Given any pointed CW complex (X,x), it is well known that the fondamental group of X pointed at x is naturally isomorphic to the automorphism group of the functor which associates to a locally constant sheaf on X its fibre at x. The purpose of this work is to generalize this fact to higher homotopy. For this we introduce the (infinite) category of locally co

Damien A. Easson

We initiate the study of Brane Gas Cosmology (BGC) on manifolds with non-trivial holonomy. Such compactifications are required within the context of superstring theory in order to make connections with realistic particle physics. We study the dynamics of brane gases constructed from various string theories on background spaces having a K3 submanifold. The K3

M. D. Scadron

We show that the nonperturbative solution of the SU(2) linear sigma model field theory requires color number Nc=3. Also, we show that the three-point and four-point functions bootstrap (or nonperturbatively ``shrink&#39;&#39;) in the chiral limit to the tree amplitudes. Independently, we show that a chiral phase transition for Nf=2 requires Tc=180 MeV, consi

Adam P. Szczepaniak, Pawel Krupinski

We investigate dynamical chiral symmetry breaking in the Coulomb gauge Hamiltonian QCD. Within the framework of the linked cluster expansion we extend the BCS ansatz for the vacuum and include correlation beyond the quark-antiquark paring. In particular we study the effects of the three-body correlations involving quark-antiquark and transverse gluons. The h

Stanislaw D. Glazek, Adam P. Szczepaniak

We consider a simplified constituent model for relativistic strong-interaction decays of hybrid mesons. The model is constructed using rules of renormalization group procedure for effective particles in light-front quantum field theory, which enables us to introduce low-energy phenomenological parameters. Boost covariance is kinematical and special relativit

Jeremiah Mans

This dissertation presents a search for a Higgs boson decaying to massive vector boson pairs. The search is based on data collected by the L3 experiment at CERN during the 1999-2000 period. We present the details and results of analyses for six of the physical channels of hZ->WWff. The combined analyses exclude a fermiophobic Higgs decaying to massive vector

Madhavan Varadarajan

Loop quantum gravity is based on a classical formulation of 3+1 gravity in terms of a real SU(2) connection. Linearization of this classical formulation about a flat background yields a description of linearised gravity in terms of a {\em real} $U(1)\times U(1)\times U(1)$ connection. A `loop&#39; representation, in which holonomies of this connection are un

Gamal G. L. Nashed

Using an axial parallel vector field we obtain two exact solutions of a vacuum gravitational field equations. One of the exact solutions gives the Schwarzschild metric while the other gives the Kerr metric. The parallel vector field of the Kerr solution have an axial symmetry. The exact solution of the Kerr metric contains two constants of integration, one b

Nikolai V. Mitskievich

In this talk r-form fields in spacetimes of any dimension D are considered (r<D). The weak-field Newtonian-type limit of Einstein&#39;s equations, in general, with relativistic sources is studied in the static case yielding a revision of the equivalence principle (intrinsically relativistic sources generate twice stronger gravitational fields and hyperrelati

Javier Nicolas Sanchez, Adam Milstein, Evan Williamson

Global mobile robot localization is the problem of determining a robot&#39;s pose in an environment, using sensor data, when the starting position is unknown. A family of probabilistic algorithms known as Monte Carlo Localization (MCL) is currently among the most popular methods for solving this problem. MCL algorithms represent a robot&#39;s belief by a set