May 2003 arXiv papers — page 31

Melissa L. Enoch, Michael E. Brown, Adam J. Burgasser

We have monitored the photometric variability of nine field L and T brown dwarfs for 10 nights during the course of one month with the Palomar 60 inch Telescope Near-Infrared Camera. Results of statistical analyses indicate that at least three of the nine targets show significant evidence for variability, and three more are possibly variable. Fractional devi

Massimo Meneghetti, Matthias Bartelmann, Lauro Moscardini, Elena Rasia

Arc statistics is known to be a powerful cosmological tool. Numerical lensing simulations show that orders of magnitude differences in the number of {\em giant} arcs on the whole sky are expected in different cosmological models. In this paper, we discuss the analytic and numerical methods in arc statistics and show that analytic models fail to reproduce the

H. Roussel, G. Helou, R. Beck, J. J. Condon

Three nearby galaxies which have abnormally high infrared to radio continuum ratios, NGC 1377, IC 1953 and NGC 4491, are investigated with a view to understanding the physical origin of their peculiarity. We review the existing data and present new radio continuum measurements along with near-infrared integral-field spectroscopy and molecular gas observation

Jan Naudts, Wojciech De Roeck

We give a rigorous description of a model of the quantized electromagnetic field interacting with quantized current fields. In the special case of classical currents our results agree with common knowledge about the problem. A toy model of a quantum current is studied as well.

Robert J. Vanderbei, David N. Spergel, N. Jeremy Kasdin

Recently, we introduced a class of shaped pupil masks, called spiderweb masks, that produce point spread functions having annular dark zones. With such masks, a single image can be used to probe a star for extrasolar planets. In this paper, we introduce a new class of shaped pupil masks that also provide annular dark zones. We call these masks starshaped mas

Junegone Chay, Chul Kim

We consider rare radiative B decays such as B -> K^* gamma or B -> rho gamma in soft-collinear effective theory, and show that the decay amplitudes are factorized to all orders in alpha_s and at leading order in Lambda/m_b.By employing two-step matching, we classify the operators for radiative B decays in powers of a small parameter lambda(~ \sqrt{Lambda/m_b

C. S. Kim, Sechul Oh, Chaehyun Yu

We study semileptonic decays B -> eta^(\prime) l nu, taking into account the flavor-singlet contribution (F^{singlet}_+) to the B -> eta^(\prime) form factors, which arises from the two-gluon emission in a decaying B meson. It has been recently pointed out that, in addition to large weak annihilation effects, the unknown value of F^{singlet}_+ prevents accur

Sostenes Lins

This work studies certain aspects of graphs embedded on surfaces. Initially, a colored graph model for a map of a graph on a surface is developed. Then, a concept analogous to (and extending) planar graph is introduced in the same spirit as planar abstract duality, and is characterized topologically. An extension of the Gauss code problem treating together t

Dmitri V. Millionschikov

We study symplectic structures on filiform Lie algebras -- nilpotent Lie algebras of the maximal length of the descending central sequence. In the present article we classify the Lie algebras with the structure relations of the following form: $$[e_i,e_j]=(j-i)e_{i+j}+\sum_{l{=}1}c_{ij}^l e_{i+j+l}, i+j \le n.$$ In even dimensions the subspace of symplectic

Serban Nacu

We study heat-bath Glauber dynamics for the ferromagnetic Ising model on a finite cycle (a graph where every vertex has degree two). We prove that the relaxation time $τ_2$ is an increasing function of any of the couplings $J_{xy}$. We also prove some further inequalities, and obtain exact asymptotics for $τ_2$ at low temperatures.

Andrey Lazarev

Motivated by ideas from stable homotopy theory we study the space of strongly homotopy associative multiplications on a two-cell chain complex. In the simplest case this moduli space is isomorphic to the set of orbits of a group of invertible power series acting on a certain space. The Hochschild cohomology rings of resulting A-infinity algebras have an inte

M. R. Ahmady, C. S. Kim, Sechul Oh, Chaehyun Yu

We calculate the branching ratios of the hadronic Λ_b decays to ηand η^\prime in the factorization approximation where the form factors are estimated via QCD sum rules and the pole model. Our results indicate that, contrary to B\to Kη^{(\prime)} decays, the branching ratios for Λ_b\toΛηand Λ_b\toΛη^\prime are more or less the same in the hadronic Λ_b transit

Clemens Heuson

A deformation of special relativity based on a dispersion relation with an energy independent speed of light and a symmetry between positive and negative energy states is proposed. The deformed Lorentz transformations, generators and algebra are derived and some consequences are discussed.

David Garfinkle, Robert Mann, Chris Vuille

We perform numerical simulations of the critical gravitational collapse of a massive vector field. The result is that there are two critical solutions. One is equivalent to the Choptuik critical solution for a massless scalar field. The other is periodic.

Thomas J. Bullard, Jayajit Das, Uwe C. Tauber

We investigate the dynamics of interacting magnetic flux lines driven by an external current in the presence of linear pinning centers, arranged either in a periodic square lattice or placed randomly in space, by means of three-dimensional Monte Carlo simulations. Compared to the non-interacting case, the repulsive forces between the vortices reduce the crit

D. D. Shivagan, P. M. Shirage, L. A. Ekal, S. H. Pawar

We report the multistep electrolytic process for the synthesis of high Tc single phase HgBa2Ca2Cu3O8+ (Hg-1223) superconducting films. The process includes : i) deposition of BaCaCu precursor alloy, ii) oxidation of BaCaCu films, iii) electrolytic intercalation of Hg in precursor BaCaCuO films and iv) electrochemical oxidation and annealing of Hg-int

R. Gonzalez-Cinca, R. Folch, R. Benitez, L. Ramirez-Piscina

The phase-field method is reviewed from the general perspective of converting a free boundary problem into a set of coupled partial differential equations. Its main advantage is that it avoids front tracking by using phase fields to locate the fronts. These fields interpolate between different constant values in each bulk phase through diffuse interfaces of

Kiyomi Okamoto, Takashi Tonegawa, Makoto Kaburagi

We explore, at T=0, the magnetic properties of the $S=1/2$ antiferromagnetic distorted diamond chain described by the Hamiltonian ${\cal H} = \sum_{j=1}^{N/3}{J_1 ({\bi S}_{3j-1} \cdot {\bi S}_{3j} + {\bi S}_{3j} \cdot {\bi S}_{3j+1}) + J_2 {\bi S}_{3j+1} \cdot {\bi S}_{3j+2} + J_3 ({\bi S}_{3j-2} \cdot {\bi S}_{3j} + {\bi S}_{3j} \cdot {\bi S}_{3j+2})} \all

D. Brockmann, T. Geisel

We investigate the dynamics of a particle moving randomly along a disordered hetero-polymer subjected to rapid conformational changes which induce superdiffusive motion in chemical coordinates. We study the antagonistic interplay between the enhanced diffusion and the quenched disorder. The dispersion speed exhibits universal behavior independent of the fold

B. A. Berg, H. Noguchi, Y. Okamoto

We introduce a new procedure to construct weight factors, which flatten the probability density of the overlap with respect to some pre-defined reference configuration. This allows one to overcome free energy barriers in the overlap variable. Subsequently, we generalize the approach to deal with the overlaps with respect to two reference configurations so th

T. Garel

Different aspects of protein folding are illustrated by simplified polymer models. Stressing the diversity of side chains (residues) leads one to view folding as the freezing transition of an heteropolymer. Technically, the most common approach to diversity is randomness, which is usually implemented in two body interactions (charges, polar character,..). On

A. M. Povolotsky, V. B. Priezzhev, Chin-Kun Hu

We use a discrete-time formulation to study the asymmetric avalanche process [Phys. Rev. Lett. vol. 87, 084301 (2001)] on a finite ring and obtain an exact expression for the average avalanche size of particles as a function of toppling probabilities depending on parameters $μ$ and $α$. By mapping the model below and above the critical line onto driven inter

M. Camarda, G. G. N. Angilella, R. Pucci, F. Siringo

The Gaussian Effective Potential in a fixed transverse unitarity gauge is studied for the static three-dimensional U(1) scalar electrodynamics (Ginzburg-Landau phenomenological theory of superconductivity). In the broken-symmetry phase the mass of the electromagnetic field (inverse penetration depth) and the mass of the scalar field (inverse correlation leng

D. J. Butler

That the RR Lyrae star period -- K-band luminosity relation is a promising tool as a distance indicator in the Milky Way and Local Group of Galaxies is apparent on observational and theoretical grounds in the literature. Less clear is the sensitivity of the relation, and consequently the physics of horizontal branch stars, to differences in stellar environme

M. J. Page, S. W. Davis, N. J. Salvi

We examine the 3-10 keV EPIC spectra of Mrk 205 and Mrk 509 to investigate their Fe K features. The most significant feature in the spectra of both objects is an emission line at 6.4 keV. The spectra can be adequately modelled with a power law and a relatively narrow (sigma < 0.2 keV) Fe K alpha emission line. Better fits are obtained when an additional Gaus

Carl H. Gibson, Rudolph E. Schild

Hubble Space Telescope (HST/ACS) images of the galaxy merger Tadpole are interpreted using the hydro-gravitational theory of Gibson 1996-2000 (HGT) that predicts galaxy masses within about 100 kpc are dominated by dark halos of planetary mass primordial-fog-particles (PFPs) in dark proto-globular-star-clusters (PGCs). According to our interpretation, stars a

Chung Kao, Geoffrey Lovelace, Lynne Orr

We have adopted two Higgs doublet models to study the production of a Higgs pseudoscalar ($A^0$) in association with a $Z$ gauge boson from gluon fusion ($gg \to ZA^0$) at the CERN Large Hadron Collider. The prospects for the discovery of $ZA^0 \to \ell \bar{\ell} b\bar{b}$ are investigated with physics backgrounds and realistic cuts. Promising results are f

Xavier Calmet, Michael Wohlgenannt

We consider Yang-Mills theories formulated on a non-commutative space-time described by a space-time dependent anti-symmetric field $θ^{μν}(x)$. Using Seiberg-Witten map techniques we derive the leading order operators for the effective field theories that take into account the effects of such a background field. These effective theories are valid for a weak

Edward Anderson, Reza Tavakol

We reformulate the Shiromizu, Maeda and Sasaki (SMS) braneworlds within the framework of the five-dimensional Einstein equations. In many applications of the braneworld Einstein field equations, the Weyl term is attributed to the bulk, thus splitting the non-Einsteinian terms into `bulk&#39; and `brane&#39; terms. Here by employing standard geometrical ident

Thomas Dent

We consider variations of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, heavy quark and superparticle thresholds and the electron mass can completely alter the (testable) relation between Delta ln alpha and Delta ln mu, where mu \equiv m_p/m_e. I

P. Zanardi, S. Lloyd

We describe a broad dynamical-algebraic framework for analyzing the quantum control properties of a set of naturally available interactions. General conditions under which universal control is achieved over a set of subspaces/subsystems are found. All known physical examples of universal control on subspaces/systems are related to the framework developed her

Lancelot F. James

Neutral to the right (NTR) processes were introduced by Doksum in 1974 as Bayesian priors on the class of distributions on the real line. Since that time there have been numerous applications to models that arise in survival analysis subject to possible right censoring. However, unlike the Dirichlet process, the larger class of NTR processes has not been use

Andreas Hanke, Ralf Metzler

The formation of local denaturation zones (bubbles) in double-stranded DNA is an important example for conformational changes of biological macromolecules. We study the dynamics of bubble formation in terms of a Fokker-Planck equation for the probability density to find a bubble of size n base pairs at time t, on the basis of the free energy in the Poland-Sc

Konrad Schmuedgen, Elmar Wagner

A Dirac operator D on the standard Podles sphere is defined and investigated. It yields a spectral triple such that |D|^{-z} is of trace class for Re z>0. Commutators with the Dirac operator give the distinguished 2-dimensional covariant differential calculus on the standard Podles sphere. The twisted cyclic cocycle associated with the volume form of the dif

P. Matlock, R. Parthasarathy, K. S. Viswanathan, Y. Yang

We study NSR strings in the Nappi-Witten background, which is the Penrose limit of a certain NS5-brane supergravity solution. We solve the theory in the light-cone gauge, obtaining the spectrum, which is space-time supersymmetric. In light of the LST/NS5-brane duality, this spectrum should be in correspondence with the states of little string theory in the a

Duiliu-Emanuel Diaconescu, Bogdan Florea, Aalok Misra

We consider world-sheet instanton effects in N=1 string orientifolds of noncompact toric Calabi-Yau threefolds. We show that unoriented closed string topological amplitudes can be exactly computed using localization techniques for holomorphic maps with involution. Our results are in precise agreement with mirror symmetry and large N duality predictions.

Gero von Gersdorff, Mariano Quiros

We apply the path-integral formalism to compute the anomalies in general orbifold gauge theories (including possible non-trivial Scherk-Schwarz boundary conditions) where a gauge group G is broken down to subgroups H_f at the fixed points y=y_f. Bulk and localized anomalies, proportional to δ(y-y_f), do generically appear from matter propagating in the bulk.

Timothy J. Hollowood

We compare the matrix model and integrable system approaches to calculating the exact vacuum structure of general N=1 deformations of either the basic N=2 theory or its generalization with a massive adjoint hypermultiplet, the N=2* theory. We show that there is a one-to-one correspondence between arbitrary critical points of the Dijkgraaf-Vafa glueball super

P. Bowcock, E. Corrigan, C. Zambon

Some ideas and remarks are presented concerning a possible Lagrangian approach to the study of internal boundary conditions relating integrable fields at the junction of two domains. The main example given in the article concerns single real scalar fields in each domain and it is found that these may be free, of Liouville type, or of sinh-Gordon type.

Rasulkhozha S. Sarafiddinov

Each of the existing types of the electric charges come forwards in the system as the source of a kind of the dipole moment. Therefore, to investigate these regularities, we have established the compound structures of Dirac and Pauli form factors. They state that the electron possesses as well as the anomalous electric charge.

Rasulkhozha S. Sharafiddinov

The mass and charge of a particle correspond to the most diverse form of the same regularity of the nature of this field. As a consequence, each of all possible types of charges testifies in favor of the existence of a kind of inertial mass. Therefore, to investigate these features, we have established the compound structures of mass and charge. They can exp

D. Dudal, H. Verschelde, V. E. R. Lemes, M. S. Sarandy

We analyze the ghost condensates <f^{abc}c^{b}c^{c}>, <f^{abc}\oc^{b}\oc^{c}> and <f^{abc}\oc^{b}c^{c}> in Yang-Mills theory in the Curci-Ferrari gauge. By combining the local composite operator formalism with the algebraic renormalization technique, we are able to give a simultaneous discussion of <f^{abc}c^{b}c^{c}>, <f^{abc}\oc^{b}\oc^{c}> and <f^{abc}\oc

Carlo Amoruso, Enzo Marinari, Olivier C Martin, Andrea Pagnani

We study domain wall energies of two dimensional spin glasses. The scaling of these energies depends on the model&#39;s distribution of quenched random couplings, falling into three different classes. The first class is associated with the exponent theta =-0.28, the other two classes have theta = 0, as can be justified theoretically. In contrast to previous

E. J. R. Parteli, H. J. Herrmann

We present a simple one-dimensional model to describe the evolution of a transverse dune field. The model is characterized by the distances between the dunes and their heights, which determine the inter-dune sand flux. The model reproduces the observation that the dunes in a given field have approximately all the same height. We find that this result is inde

Pasquale Calabrese, Andrea Pelissetto, Ettore Vicari

We compute the crossover exponent $ϕ$ describing the crossover from the random-exchange to the random-field critical behavior in Ising systems. For this purpose, we consider the field-theoretical approach based on the replica method, and perform a six-loop calculation in the framework of a fixed-dimension expansion. The crossover from random-exchange to rand

O. Sørensen, D. V. Fedorov, A. S. Jensen

We investigate systems of identical bosons with the focus on two-body correlations and attractive finite-range potentials. We use a hyperspherical adiabatic method and apply a Faddeev type of decomposition of the wave function. We discuss the structure of a condensate as function of particle number and scattering length. We establish universal scaling relati

S. Satheesh, E. Sandhya

Continuing the study reported in Satheesh (2001),(math.PR/0304499 dated 01 May 2003) and Satheesh (2002)(math.PR/0305030 dated 02May 2003), here we study generalizations of infinitely divisible (ID) and max-infinitely divisible (MID) laws. We show that these generalizations appear as limits of random sums and random maximums respectively. For the random samp

V. Bozza, L. Mancini

We calculate the time delay between different relativistic images formed by black hole gravitational lensing in the strong field limit. For spherically symmetric black holes, it turns out that the time delay between the first two images is proportional to the minimum impact angle. Their ratio gives a very interesting and precise measure of the distance of th

Saul Barshay, Georg Kreyerhoff

Using data from atmospheric neutrino mixing, and a simple functional form for mixing angles, the absolute values of three neutrino masses are calculated: $m_3\cong 5.37\times 10^{-2} eV$, $m_2\cong 1.94\times 10^{-2} eV$, $m_1\cong 1.46\times 10^{-2} eV$. The quantities relevant for solar neutrino mixing are calculated: $(m_2^2-m_1^2) \cong 1.63\times 10^{-4

N. Mukunda, Arvind, S. Chaturvedi, R. Simon

We consider the problem of setting up the Wigner distribution for states of a quantum system whose configuration space is a Lie group. The basic properties of Wigner distributions in the familiar Cartesian case are systematically generalised to accommodate new features which arise when the configuration space changes from $n$-dimensional Euclidean space ${\c

Masayasu Harada, Masafumi Kurachi, Koichi Yamawaki

We solve the homogeneous Bethe-Salpeter (HBS) equation for the scalar, pseudoscalar, vector, and axial-vector bound states of quark and anti-quark in large Nf QCD with the improved ladder approximation in the Landau gauge. The quark mass function in the HBS equation is obtained from the Schwinger-Dyson (SD) equation in the same approximation for consistency

Tsutomu Kobayashi, Hideaki Kudoh, Takahiro Tanaka

We study primordial gravitational waves from inflation in Randall-Sundrum braneworld model. The effect of small change of the Hubble parameter during inflation is investigated using a toy model given by connecting two de Sitter branes. We analyze the power spectrum of final zero-mode gravitons, which is generated from the vacuum fluctuations of both initial

A. Buchleitner, A. R. Kolovsky

We show that the energy spectrum of the Bose-Hubbard model amended by a static field exhibits Wigner-Dyson level statistics. In itself a characteristic signature of quantum chaos, this induces the irreversible decay of Bloch oscillations of cold, interacting atoms loaded into an optical lattice, and provides a Hamiltonian model for interaction induced decohe

L. Herrera, N. O. Santos

The shear free condition is studied for dissipative relativistic self-gravitating fluids in the quasi-static approximation. It is shown that, in the Newtonian limit, such condition implies the linear homology law for the velocity of a fluid element, only if homology conditions are further imposed on the temperature and the emission rate. It is also shown tha

Qiang Zhao, Frank E. Close

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality. The essential principles are illustrated in a pedagogic model of a composite system with two spinless charged constituents, for which a dual picture for the low-energy resonance phenomena and high-energy scal

Yoshifumi Hyakutake

We construct a solution of the BFSS matrix theory, which is a counterpart of the BIon solution representing a fundamental string ending on a bound state of a D2-brane and D0-branes. We call this solution the `fuzzy BIon&#39; and show that this configuration preserves 1/4 supersymmetry of type IIA superstring theory. We also construct an effective action for

Yong-Jin Chun, Hai-Woong Lee

We study the problem of measurement-induced decoherence using the phase-space approach employing the Gaussian-smoothed Wigner distribution function. Our investigation is based on the notion that measurement-induced decoherence is represented by the transition from the Wigner distribution to the Gaussian-smoothed Wigner distribution with the widths of the smo

Zhan Xu, Bei Zeng

This paper has been withdrawn.

N. P. Mehta, C. Felline, J. R. Shepard, J. Piekarewicz

Modern effective-theory techniques are applied to the nuclear many-body problem. A novel approach is proposed for the renormalization of operators in a manner consistent with the construction of the effective potential. To test this approach, a one-dimensional, yet realistic, nucleon-nucleon potential is introduced. An effective potential is then constructed

C. B. Das, S. Das Gupta, A. Z. Mekjiani

We consider a soluble model of multifragmentation which is similar in spirit to many models which have been used to fit intermediate energy heavy ion collision data. In this model $c_v$ is always positive but for finite nuclei $c_p$ can be negative for some temperatures and pressures. Furthermore, negative values of $c_p$ can be obtained in canonical treatme

V. A. Rodin, Amand Faessler, F. Šimkovic, Petr Vogel

The nuclear matrix elements $M^{0ν}$ of the neutrinoless double beta decay ($0νββ$) are evaluated for $^{76}$Ge,$^{100}$Mo, $^{130}$Te, and $^{136}$Xe within the Renormalized Quasiparticle Random Phase Approximation (RQRPA) and the simple QRPA. Three sets of single particle level schemes are used, ranging in size from 9 to 23 orbits. When the strength of the

B. Saghai, Z. Li

eta photoproduction data on the proton up to E=2 GeV are interpreted within a chiral constituent quark formalism, which embodies all known three and four star resonances. This study confirms the need for a new S11 resonance, with M=1.780 GeV and Gamma=280 MeV, already introduced in investigating lower energy data.

Petr Vogel

I describe how the signals corresponding to the supernova $ν_e$ and $\barν_e$ (charged current reactions) as well as all active neutrinos (neutral current reactions) can be separately observed in various existing detectors. These observations would make it possible to determine the flux and average energy (or temperature) for each of these three neutrino sig

K. Tucci, M. G. Cosenza, O. Alvarez-Llamoza

The phase ordering dynamics of coupled chaotic maps on fractal networks are investigated. The statistical properties of the systems are characterized by means of the persistence probability of equivalent spin variables that define the phases. The persistence saturates and phase domains freeze for all values of the coupling parameter as a consequence of the f

Hidetsugu Sakaguchi

We study a simple replicator model with non-symmetric and nonlocal interactions. Hierarchical structures with prey-predator relations are self-organized from a homogeneous state, induced by the dynamical instability of nonlinear interactions.

Hidetsugu Sakaguchi, Takefumi Fujimoto

Spiral chaos appears in the two dimensional Aliev-Panfilov model. The generation mechanism of the spiral chaos is related to the breathing instability of pulse trains. The spiral chaos can be eliminated by applying periodic force uniformly. The elimination of spiral chaos is most effective, when the frequency of the periodic force is close to that of the bre

Paolo Maria Mariano

The influence of the material texture (substructure) on the force driving the crack tip in complex materials admitting Ginzburg-Landau-like energies is analyzed in a three-dimensional continuum setting. The theory proposed accounts for finite deformations and general coarse-grained order parameters. A modified expression of the J-integral is obtained togethe

C. Quesne

Jackson&#39;s q-exponential is expressed as the exponential of a series whose coefficients are obtained in closed form. Such a relation is used to derive some properties of the q-exponential.

S. S. Serova, S. A. Serov

Algorithm of construction of all knots, links with given number of crosses on diagram of knot, link is offered. This algorithm is based on simple proposition, that there is a representation of knot (link) as closure of braid with n threads and length of this braid does not exceed n(4n-5)+2.

John Terilla, Thomas Tradler

We develop the deformation theory of A_\infty algebras together with \infty inner products and identify a differential graded Lie algebra that controls the theory. This generalizes the deformation theories of associative algebras, A_\infty algebras, associative algebras with inner products, and A_\infty algebras with inner products.

Thomas Bouetou Bouetou

We give the classification of solvable and splitting Lie triple system and it turn that, up to isomorphism there exist 7 non isomorphic canonical Lie triple systems and 6 non isomorphic splitting canonical Lie triple systems and find the solvable Lie algebras associated.

Tom Leinster

Higher-dimensional category theory is the study of n-categories, operads, braided monoidal categories, and other such exotic structures. It draws its inspiration from areas as diverse as topology, quantum algebra, mathematical physics, logic, and theoretical computer science. This is the first book on the subject and lays its foundations. Many examples are g

Martin Klazar

We investigate extremal functions ex_e(F,n) and ex_i(F,n) counting maximum numbers of edges and maximum numbers of vertex-edge incidences in simple hypergraphs H which have n vertices and do not contain a fixed hypergraph F; the containment respects linear orderings of vertices. We determine both functions exactly if F has only distinct singleton edges or if

Ralf Schindler

It is shown that if BMM (= Bounded Martin&#39;s Maximum) holds then each set is contained in an inner model with a strong cardinal. This answers a question that has been asked by various people. It follows that BMM has a much larger consistency strength than BSPFA (= the Bounded Semi-proper Forcing Axiom).

Cristiana Bertolin

Let M be a 1-motive defined over a field of characteristic 0. To M we can associate its motivic Galois group, G_mot(M), which is the geometrical interpretation of the Munford-Tate group of M. We prove that the unipotent radical of the Lie algebra of G_mot(M) is the semi-abelian variety defined by the adjoint action of the semi-simplified of the Lie algebra o

Alessio Pomponio, Simone Secchi

We prove the existence of one or more solutions to a singularly perturbed elliptic problema with two potential functions.

R. Jackiw

The original ideas about noncommuting coordinates are recalled. The connection between U(1) gauge fields defined on noncommuting coordinates and fluid mechanics is explained. Non-Abelian fluid mechanics is described.

Elso Drigo Filho, Regina Maria Ricotta

Within the approach of Supersymmetric Quantum Mechanics associated with the variational method a recipe to construct the superpotential of three dimensional confined potentials in general is proposed. To illustrate the construction, the energies of the Harmonic Oscillator and the Hulthén potential, both confined in three dimensions are evaluated. Comparison

Patricio Gaete

For a recently proposed pure gauge theory in three dimensions, without a Chern-Simons term, we calculate the static interaction potential within the structure of the gauge-invariant variables formalism. The result coincides with that of the Maxwell-Chern-Simons theory in the short distance regime, which shows the confining nature of the potential.

C. Macesanu, A. Mitov, S. Nandi

In this paper, we derive from the viewpoint of the effective 4D theory the interaction terms between linearized gravity propagating in N>= 2 large extra dimensions and matter propagating into one extra dimension. This generalizes known results for the interactions between gravity and 4D matter in ADD-type models. Although we assume that matter is described b

T. Barnes, F. E. Close, H. J. Lipkin

We discuss the implications of a possible quasinuclear DK bound state at 2.32 GeV. Evidence for such a state was recently reported in D_s^+pi^o by the BaBar Collaboration. We first note that a conventional quark model c-sbar assignment is implausible, and then consider other options involving multiquark systems. An I=0 c sbar n nbar baryonium assignment is o

Kiwoon Choi, Do Young Kim, Ian-Woo Kim, Tatsuo Kobayashi

We examine the soft supersymmetry breaking parameters in supersymmetric theories on a slice of AdS_5 which generate the hierarchical Yukawa couplings by dynamically localizing the bulk matter fields in extra dimension. Such models can be regarded as the AdS dual of the recently studied 4-dimensional models which contain a supersymmetric CFT to generate the h

John M. LoSecco

We note a discrepancy between the value of R expected on the basis of the muon neutrino angular distribution and the value actually observed. The energy independence of $R$ leads to a fine tuning problem. This may be indicative of some unaccounted for new physics.

F. Jugeau, H. Sazdjian

The large-distance dynamics in quarkonium systems is investigated, in the large N limit, through the saturation of Wilson loop averages by minimal surfaces. Using a representation for the quark propagator in the presence of the external gluon field based on the use of path-ordered phase factors, a covariant three-dimensional bound state equation of the Breit

Masako Bando, Midori Obara

We demonstrate that under the &#34;symmetric zero texture&#34; with minimal Majorana mass matrix, neutrino masses and mixing angles are expressed in terms of up-quark masses, $m_t,m_c,m_u$. This provides interesting relations among neutrino mixing angles and up-type quark masses. Especially we predict $|U_{e3}| \leq 0.11$ even if we include the small mixing

J. Harada

We study assignments of the hypercharge and baryon minus lepton number for particles in the $E_6$ grand unification model. It is shown that there are three assignments of hypercharge and three assignments of baryon minus lepton number which are consistent with the Standard Model. Their explicit expressions and detailed properties are given. In particular, we

Satoru Kaneko, Makoto Katsumata, Morimitsu Tanimoto

The leptogenesis is studied in the neutrino textures with two zeros, which reduce the number of independent phases of the CP violation. The phenomenological favored neutrino textures with two zeros are decomposed into the Dirac neutrino mass matrix and the right-handed Majorana one in the see-saw mechanism. Putting the condition to suppress the $μ\to eγ$ dec

John M. LoSecco

We summarize results on a number of observations of penguin dominated radiative decays of the B meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment at PEP-II, the asymmetric B factory at SLAC.

M. Convery, B. Ratcliff, X. Sarazin, J. Schwiening

The DIRC is a new type of Cherenkov detector that is successfully operating as the hadronic particle identification system for the BABAR experiment at SLAC. The fused silica bars that serve as the DIRC&#39;s Cherenkov radiators must transmit the light over long optical pathlengths with a large number of internal reflections. This imposes a number of stringen

Akihiro Ishibashi, Robert M. Wald

It was previously shown by one of us that in any static, non-globally-hyperbolic, spacetime it is always possible to define a sensible dynamics for a Klein-Gordon scalar field. The prescription proposed for doing so involved viewing the spatial derivative part, $A$, of the wave operator as an operator on a certain $L^2$ Hilbert space $\mathcal H$ and then de

L. Brenig, A. Figueiredo, E. Gunzig, T. M. Rocha Filho

We consider here the dynamics of some homogeneous and isotropic cosmological models with $N$ interacting classical scalar fields non-minimally coupled to the spacetime curvature, as an attempt to generalize some recent results obtained for one and two scalar fields. We show that a Lyapunov function can be constructed under certain conditions for a large clas

Osvaldo M. Moreschi

We present a definition of angular momentum for radiative spacetimes which does not suffer from any ambiguity of supertranslations. We succeed in providing an appropriate notion of {\it intrinsic} angular momentum; and at the same time a definition of center of mass frame at future null infinity. We use the center of mass frame to present the asymptotic stru

L. R. Abramo, L. Brenig, E. Gunzig, A. Saa

We show that the action of Einstein&#39;s gravity with a scalar field coupled in a generic way to spacetime curvature is invariant under a particular set of conformal transformations. These transformations relate dual theories for which the effective couplings of the theory are scaled uniformly. In the simplest case, this class of dualities reduce to the S-d

L. R. Abramo, L. Brenig, E. Gunzig, Alberto Saa

We investigate the dynamics of Einstein equations in the vicinity of the two recently described types of singularity of anisotropic and homogeneous cosmological models described by the action $$ S=\int d^4x \sqrt{-g}{F(ϕ)R - \partial_aϕ\partial^aϕ-2V(ϕ)}, $$ with general $F(ϕ)$ and $V(ϕ)$. The dynamical nature of each singularity is elucidated, and we show t

Monaldo Mastrolilli, Marcus Hutter

We address the classical knapsack problem and a variant in which an upper bound is imposed on the number of items that can be selected. We show that appropriate combinations of rounding techniques yield novel and powerful ways of rounding. As an application of these techniques, we present a linear-storage Polynomial Time Approximation Scheme (PTAS) and a Ful

Florian R. Krajewski, Martin H. Müser

Discrete sine-Gordon (SG) chains are studied with path-integral molecular dynamics. Chains commensurate with the substrate show the transition from collective quantum creep to pinning at bead masses slightly larger than those predicted from the continuous SG model. Within the creep regime, a field-driven transition from creep to complete depinning is identif

T. Wojtowicz, W. L. Lim, X. Liu, M. Dobrowolska

The effect of modulation doping by Be on the ferromagnetic properties of Ga(1-x)Mn(x)As is investigated in Ga(1-x)Mn(x)As/Ga(1-y)Al(y)As heterojunctions and quantum wells. Introducing Be acceptors into the Ga(1-y)Al(y)As barriers leads to an increase of the Curie temperature T_C of Ga(1-x)Mn(x)As, from 70 K in undoped structures to over 100 K with the modula

A. V. Sermyagin

Experimental data on signal and noise characteristics of high--$T_c$ RF SQUIDs with large inductance of quantization loop are presented. The SQUIDs were produced by a thick--film HTS--technique of painting on the Y$_2$BaCuO$_5$ substrate. For the first time, a steady quantum interference was observed in RF SQUID with the inductance as large as $L_S=6.6$ nH,

Sigmund Kohler, Fernando Sols

When subject to an external time periodic perturbation of frequency $f$, a Josephson-coupled two-state Bose-Einstein condensate responds with a constant chemical potential difference $Δμ=khf$, where $h$ is Planck&#39;s constant and $k$ is an integer. We propose an experimental procedure to produce ac-driven atomic Josephson devices that may be used to define

Andrea Montanari, Federico Ricci-Tersenghi

We investigate numerically the dynamics of three different spin models in the aging regime. Each of these models is meant to be representative of a distinct class of aging behavior: coarsening systems, discontinuous spin glasses, and continuous spin glasses. In order to study dynamic heterogeneities induced by quenched disorder, we consider single-spin obser