Searching Arxiv, refresh for possibly better results.

Results for "F. M. Addesa"

total 241967took 0.18s
Commissioning and operation of the Cherenkov detector for proton Flux Measurement of the UA9 ExperimentApr 12 2019The UA9 Experiment at CERN-SPS investigates channeling processes in bent silicon crystals with the aim to manipulate hadron beams. Monitoring and characterization of channeled beams in the high energy accelerators environment ideally requires in-vacuum ... More
The relativistic nuclear dynamics for the SU(3) Goldstone bosons of chiral QCDDec 04 2002In this habilitation theses the chiral SU(3) Lagrangian is applied to antikaon and hyperon propagation in cold nuclear matter. The self consistent many-body dynamics relies on a detailed analysis of the pion, kaon and antikaon-nucleon scattering data ... More
Migdal's short range correlations in a covariant modelOct 26 2002Aug 13 2003We construct a covariant model for short range correlations of a pion emerged in nuclear matter. Once the delta-hole contribution is considered an additional and so far neglected channel opens that leads to significant modifications in the vicinity of ... More
Correlation effects in two-dimensional topological insulatorsNov 08 2012Mar 07 2013Topological insulators have become one of the most active research areas in condensed matter physics. This article reviews progress on the topic of electronic correlations effects in the two-dimensional case, with a focus on systems with intrinsic spin-orbit ... More
Luttinger Liquid Physics and Spin-Flip Scattering on Helical EdgesOct 14 2011Feb 22 2012We investigate electronic correlation effects on edge states of quantum spin-Hall insulators within the Kane-Mele-Hubbard model by means of quantum Monte Carlo simulations. Given the U(1) spin symmetry and time-reversal invariance, the low-energy theory ... More
Efficient calculation of imaginary time displaced correlation functions in the projector auxiliary field quantum Monte-Carlo algorithmSep 28 2000The calculation of imaginary time displaced correlation functions with the auxiliary field projector quantum Monte-Carlo algorithm provides valuable insight (such as spin and charge gaps) in the model under consideration. One of the authors and M. Imada ... More
Oscillation of a rigid rod in the special relativityDec 27 2011In the special relativity, a rigid rod slides upon itself, with one extremity oscillating harmonically. We discovered restrictions in the amplitude of the motion and in the length of the rod, essential to eliminate unphysical solutions. ------- Cxe la ... More
Dynamics of kaons in nuclear matterFeb 11 1998May 27 1998We consider $K^-$ nucleon elastic and inelastic scattering in isospin symmetric nuclear matter. It is found that the proper description of the $\Lambda(1405)$ resonance structure in nuclear matter requires a self-consistent approach. Then the $\Lambda ... More
Bichromatic State-Insensitive Trapping of Cold 133Cs-87Rb Atomic MixturesOct 14 2015We investigate simultaneous state-insensitive trapping of a mixture of two different atomic species, Caesium and Rubidium. The magic wavelengths of the Caesium and Rubidium atoms are different, $935.6$ nm and $789.9$ nm respectively, thus single-frequency ... More
Hole Dynamics in Two-Dimensional Antiferromagnetic Mott InsulatorsNov 27 1998The dispersion relation of a doped hole in the half-filled 2D Hubbard model is shown to follow a k^4 law around the (0,pi) and (pi,0) points in the Brillouin zone. Upon addition of pair-hopping processes this dispersion relation is unstable towards a ... More
Insulator-Metal Transition in the One and Two-Dimensional Hubbard ModelsOct 16 1995We use Quantum Monte Carlo methods to determine $T=0$ Green functions, $G(\vec{r}, \omega)$, on lattices up to $16 \times 16$ for the 2D Hubbard model at $U/t =4$. For chemical potentials, $\mu$, within the Hubbard gap, $ |\mu | < \mu_c$, and at {\it ... More
On the measurement of B(E2, 0+ -> 2+) using intermediate-energy Coulomb excitationAug 22 2007Coulomb excitation is a standard method used to extract quadrupole excitation strengths of even-even nuclei. In typical analyses the reaction is assumed to be one-step, Coulomb only, and is treated within a semi-classical model. In this work, fully-quantal ... More
Stable Quantum Monte Carlo Algorithm for $T=0$ Calculation of Imaginary Time Green FunctionsAug 25 1995We present a numerically stable Quantum Monte Carlo algorithm to calculate zero-temperature imaginary-time Green functions $ G(\vec{r}, \tau) $ for Hubbard type models. We illustrate the efficiency of the algorithm by calculating the on-site Green function ... More
Doping induced metal-insulator transition in two-dimensional Hubbard, $t-U$, and extended Hubbard, $t-U-W$, modelsNov 18 1997We show numerically that the nature of the doping induced metal-insulator transition in the two-dimensional Hubbard model is radically altered by the inclusion of a term, $W$, which depends upon a square of a single-particle nearest-neighbor hopping. ... More
Classical statistical mechanics of a few-body interacting spin modelNov 12 1999We study the emergence of Boltzmann's law for the "single particle energy distribution" in a closed system of interacting classical spins. It is shown that for a large number of particles Boltzmann's law may occur, even if the interaction is very strong. ... More
Real payoffs and virtual trading in agent based market modelsNov 12 2003Apr 03 2004The \$-Game was recently introduced as an extension of the Minority Game. In this paper we compare this model with the well know Minority Game and the Majority Game models. Due to the inter-temporal nature of the market payoff, we introduce a two step ... More
Reversing type II migration: resonance trapping of a lighter giant protoplanetMar 28 2000Jan 18 2001We present a mechanism related to the migration of giant protoplanets embedded in a protoplanetary disc whereby a giant protoplanet is caught up, before having migrated all the way to the central star, by a lighter outer giant protoplanet. This outer ... More
New Benchmark of X-ray Line Emission Models of Fe XVIIMay 05 2009We review the accuracy of existing \ion{Fe}{17} X-ray line emission models by comparing them with an extensive analysis of \textit{Chandra} high energy transmission grating (HETG) observations of stellar coronae. We find significant discrepancies between ... More
OPE of the pseudoscalar gluonium correlator in massless QCD to three-loop orderApr 08 2013Jul 05 2013In this paper analytical results are presented for higher order corrections to coefficient functions of the operator product expansion (OPE) for the correlator of two pseudoscalar gluonium operators \tilde{O}_1=G^{\mu \nu}\tilde{G}_{\mu \nu}. The Wilson ... More
Four-loop QCD $β$-function with different fermion representations of the gauge groupAug 31 2016Oct 17 2016We present analytical results at four-loop level for the $\beta$-function of the coupling of a generic gauge group and any number of different quark representations. From this we can directly derive the gluino contribution to the strong coupling $\beta$-function ... More
Fiber-Optic-Gyroscope Measurements Close to Rotating Liquid HeliumNov 05 2009We previously reported anomalous fiber-optic gyroscope signals observed above rotating rings at temperatures close to liquid helium. Our results suggested that the liquid helium itself may be the source of our observed phenomenon. We constructed a new ... More
Vacuum Nodes in QCD at $θ=π$: Exact ResultsNov 13 1997We show that the vacuum functional of 3+1 dimensional non-abelian gauge theories vanishes for some classical field configurations $\psi_0(A)=0$ when the coefficient of the CP violating $\theta$--term becomes $\theta=\pi$ (mod. $2\pi$). Some of these classical ... More
Higgs- and Goldstone bosons-mediated long range forcesOct 30 1998In certain mild extensions of the Standard Model, spin-independent long range forces can arise by exchange of two very light pseudoscalar spin--0 bosons. In particular, we have in mind models in which these bosons do not have direct tree level couplings ... More
Electromagnetic field quantization in an anisotropic magnetodielectric medium with spatial-temporal dispersionDec 15 2008By modeling a linear, anisotropic and inhomogeneous magnetodielectric medium with two independent set of harmonic oscillators, electromagnetic field is quantized in such a medium. The electric and magnetic polarizations of the medium are expressed as ... More
Quantum electromdynamics in a linear absorbing dielectric mediumAug 15 2005The eletromagnetic field in a linear absorptive dielectric medium, is quantized in the framework of the damped polarization model. A Hamiltonian containing a reservoir with continuous degrees of freedom, is proposed. The reservoir minimally interacts ... More
The Effective String of 3D Gauge Systems at the Deconfining TransitionOct 01 1991It is argued that the effective string of whatever 3D gauge system at the deconfining transition is universally described by the minimal $N=2$ extended superconformal theory at $c=1$. A universal value of the critical temperature is predicted.
Energy dependence of current noise in superconducting/normal metal junctionsOct 17 2003Interference of electronic waves undergoing Andreev reflection in diffusive conductors determines the energy profile of the conductance on the scale of the Thouless energy. A similar dependence exists in the current noise, but its behavior is known only ... More
PELCR: Parallel Environment for Optimal Lambda-Calculus ReductionJul 22 2004Jul 23 2004In this article we present the implementation of an environment supporting L\'evy's \emph{optimal reduction} for the $\lambda$-calculus \cite{Lev78} on parallel (or distributed) computing systems. In a similar approach to Lamping's one in \cite{Lamping90}, ... More
Adiabatic solution of Dirac equation of "graphinos" in an intense electromagnetic field and emission of high order harmonics near the Dirac pointsFeb 08 2011Mar 01 2011We obtain a class of adiabatic solutions of Dirac equation for the charged massless relativistic quasi-particles that arise from the low-energy excitations \cite{foot-1} in a 2D graphene sheet, interacting with an electromagnetic field. The analytic solutions ... More
A 4-Component Dirac Theory of Ionization of Hydrogen Molecular Ion in a Super-Intense Laser FieldJul 10 2009Jul 11 2009In this paper a 4-component Dirac theory of ionization of hydrogen molecular ion in a super-intense laser field is developed. Simple analytic expressions for the spin specific as well as the total ionization currents emitted from the ground state of the ... More
Photometric study of eclipsing binary RV TriFeb 21 2002We present new photometric observations of RV Tri. A complete light curve was obtained in the R and V filters. These light curves were processed by the Wilson-Devinney (WD) code and the FOTEL to get solution of this eclipsing binary system. We discuss ... More
Wilson Renormalization Group for Supersymmetric Gauge Theories and Gauge AnomaliesFeb 27 1998We extend the Wilson renormalization group (RG) to supersymmetric theories. As this regularization scheme preserves supersymmetry, we exploit the superspace technique. To set up the formalism we first derive the RG flow for the massless Wess-Zumino model ... More
Radio Images of 3C 58: Expansion and Motion of its WispMar 08 2006New 1.4 GHz VLA observations of the pulsar-powered supernova remnant 3C 58 have resulted in the highest-quality radio images of this object to date. The images show filamentary structure over the body of the nebula. The present observations were combined ... More
Statistical properties of an ensemble of vortices interacting with a turbulent fieldJun 10 2005Sep 22 2005We develop an analytical formalism to determine the statistical properties of a system consisting of an ensemble of vortices with random position in plane interacting with a turbulent field. We calculate the generating functional by path-integral methods. ... More
Describing two-dimensional vortical flows : the typhoon caseMar 18 2005Mar 31 2005We present results of a numerical study of the differential equation governing the stationary states of the two-dimensional planetary atmosphere and magnetized plasma (within the Charney Hasegawa Mima model). The most strinking result is that the equation ... More
Soliton self-modulation of the turbulence amplitude and plasma rotationApr 17 2002May 29 2002The space-uniform amplitude envelope of the Ion Temperature Gradient driven turbulence is unstable to small perturbations and evolves to nonuniform, soliton-like modulated profiles. The induced poloidal asymmetry of the transport fluxes can generate spontaneous ... More
An analogy between optical turbulence and activator-inhibitor dynamicsJul 18 2016The propagation of laser beams through madia with cubic nonlinear polarization is part of a wide range of practical applications. The processes that are involved are at the limit of extreme (cuasi-singular) concentration of intensity and the transversal ... More
Damage spreading in the mode-coupling equations for glassesNov 27 1997We examine the problem of damage spreading in the off-equilibrium mode coupling equations. The study is done for the spherical $p$-spin model introduced by Crisanti, Horner and Sommers. For $p>2$ we show the existence of a temperature transition $T_0$ ... More
Rare Supersymmetric Top Quark DecaysAug 28 1993Sep 07 1993{Two supersymmetric decays of the top quark, $\thb$ and $\tstopneu$, are discussed within the framework of the Minimal Supersymmetric Standard Model with radiatively induced breaking of $SU(2)\times U(1)$. The present possibility of detecting these decays, ... More
Jordan product commuting maps with $λ$-Aluthge transformJun 20 2016Jul 22 2016Let H and K be two complex Hilbert spaces and B(H) be the algebra of bounded linear operators from H into itself. The main purpose in this paper is to obtain a characterization of bijective maps $\Phi$ : B(H) $\rightarrow$ B(K) satisfying the following ... More
A New Model for the Width of the Broad Emission Lines in AGN: The Role of the Accretion RateMay 08 2000We present a model which relates the Broad Emission Line Regions of AGN to the accretion mechanism. Based on the Keplerian assumption for the high velocity clouds of the gas responsible for the production of the Broad Emission Lines, we identify that ... More
Effective Lagrangians for Orientifold TheoriesSep 28 2003We construct effective Lagrangians of the Veneziano-Yankielowicz (VY) type for two non-supersymmetric theories which are orientifold daughters of supersymmetric gluodynamics (containing one Dirac fermion in the two-index antisymmetric or symmetric representation ... More
General relativity and the growth of a sub-discipline "gravitation" in the German speaking physics communityJul 12 2016We will follow the growth of gravitational theory in Germany from 1915 to the 1990s, i.e., relativistic theories of gravitation, mainly Einstein's, as a branch of physics in the sense of social, more precisely institutional history. As criteria for a ... More
On the Constancy of the Pontryagin Hamiltonian for Autonomous ProblemsAug 18 2003We provide a new, simpler, and more direct proof of the well known fact that for autonomous optimal control problems the Pontryagin extremals evolve on a level surface of the respective Pontryagin Hamiltonian.
Caratheodory-Equivalence, Noether Theorems, and Tonelli Full-Regularity in the Calculus of Variations and Optimal ControlJun 21 2002We study, in a unified way, the following questions related to the properties of Pontryagin extremals for optimal control problems with unrestricted controls: i) How the transformations, which define the equivalence of two problems, transform the extremals? ... More
Initial Conditions for Idealised Clusters Mergers, simulating El GordoNov 27 2013Simulations of isolated binary mergers of galaxy clusters are a useful tool to study the evolution of these objects. For exceptionally massive systems they even represent the only viable way of simulation, because these are rare in typical cosmological ... More
Low voltage conductance of small tunnel junctionsJul 06 1992A discrete charge transfer in a small tunnel junction where Coulomb interactions are important can excite electron-hole pairs near the Fermi level. We use a simple model to study the associated nonequilibrium properties and found two novel effects: (i) ... More
Emptiness and Depletion Formation Probability in spin models with inverse square interactionAug 19 2009Nov 15 2009We calculate the Emptiness Formation Probability (EFP) in the spin-Calogero Model (sCM) and Haldane-Shastry Model (HSM) using their hydrodynamic description. The EFP is the probability that a region of space is completely void of particles in the ground ... More
Quantum Chaos and Thermalization for Interacting ParticlesNov 19 1999In this review the problem of statistical description of isolated quantum systems of interacting particles is discussed. Main attention is paid to a recently developed approach which is based on chaotic properties of compound states in the basis of non-interacting ... More
The Outbursts of Classical and Recurrent NovaeNov 27 2009Nov 22 2011In this review, I present our current state of knowledge regarding both Classical Nova and Recurrent Nova systems. Two particular objects (V1974 Cyg and RS Oph) are chosen to illustrate the range of phenomena that may be associated with their outbursts. ... More
High Spatial Resolution Optical and Radio Imagery of the Circumbinary EnvironmentJan 22 2004Jan 24 2004In this review, I concentrate on describing observations of spatially resolved emission in symbiotic stars at sub-arcsecond scales. In some of the closer objects, the highest resolutions discussed here correspond to linear dimensions similar to the supposed ... More
Semiclassical matrix elements for a chaotic propagator in the Scar functions basisJun 17 2013A semiclassical approximation for the matrix elements of a quantum chaotic propagator in the scar function basis has been derived. The obtained expression is solely expressed in terms of canonical invariant objects. For our purpose, we have used, the ... More
Pareto's Law of Income Distribution: Evidence for Germany, the United Kingdom, and the United StatesApr 29 2005Mar 08 2006We analyze three sets of income data: the US Panel Study of Income Dynamics PSID), the British Household Panel Survey (BHPS), and the German Socio-Economic Panel (GSOEP). It is shown that the empirical income distribution is consistent with a two-parameter ... More
Monte Carlo simulations of interfaces in polymer blendsMar 10 1998We review recent simulation studies of interfaces between immiscible homopolymer phases. Special emphasis is given to the presentation of efficient simulation techniques and powerful methods of data analysis, such as the analysis of capillary wave spectra. ... More
The Three-Wave Resonant Interaction: Deformation of the Plane-Wave Solutions and Darboux TransformationsJan 11 1996The plane wave solutions of the three-wave resonant interaction in the plane are considered. It is shown that rank-one constraints over the right derivatives of invertible operators on an arbitrary linear space gives solutions of the three-wave resonant ... More
Presentations from DIS2002 in KrakowMay 17 2002Both of my talks at DIS2002, on Generalised Parton Distributions and Nuclear Shadowing are presented. In an appendix I summarise some of the discussions which followed the talks.
More discoveries of compact radio cores in Seyfert galaxies with the EVNDec 13 2010Following the high detection rate achieved by EVN observations of the central regions of local Seyfert galaxies (Giroletti & Panessa 2009, ApJL 706, 260), we have targeted a few additional sources from a complete sample. We have detected three more sources ... More
A version of Hörmander's theorem for the fractional Brownian motionMay 25 2006It is shown that the law of an SDE driven by fractional Brownian motion with Hurst parameter greater than 1/2 has a smooth density with respect to Lebesgue measure, provided that the driving vector fields satisfy H\"ormander's condition. The main new ... More
A shortcut for evaluating some log integrals from products and limitsSep 03 2009Aug 25 2012In this short paper, I introduce an elementary method for exactly evaluating the definite integrals $\, \int_0^{\pi}{\ln{(\sin{\theta})}\,d\theta}$, $\int_0^{\pi/2}{\ln{(\sin{\theta})}\,d\theta}$, $\int_0^{\pi/2}{\ln{(\cos{\theta})}\,d\theta}$, and $\int_0^{\pi/2}{\ln{(\tan{\theta})}\,d\theta} ... More
Rare cosmological events recorded in muscovite micaJan 23 2019A study of fossil tracks of charged particles recorded in crystals of muscovite has revealed evidence of rare events of cosmological origin. The events are not compatible with known particle interactions with matter. They were recorded during a period ... More
The Variational Calculus on Time ScalesJun 18 2011The discrete, the quantum, and the continuous calculus of variations, have been recently unified and extended by using the theory of time scales. Such unification and extension is, however, not unique, and two approaches are followed in the literature: ... More
Integrals of Motion for Discrete-Time Optimal Control ProblemsJan 24 2003We obtain a discrete time analog of E. Noether's theorem in Optimal Control, asserting that integrals of motion associated to the discrete time Pontryagin Maximum Principle can be computed from the quasi-invariance properties of the discrete time Lagrangian ... More
Can Complex Collective Behaviour Be Generated Through Randomness, Memory and a Pinch of Luck?Nov 29 2017Machine Learning techniques have been used to teach computer programs how to play games as complicated as Chess and Go. These were achieved using powerful tools such as Neural Networks and Parallel Computing on Supercomputers. In this paper, we define ... More
Regularity of transition semigroups associated to a 3D stochastic Navier-Stokes equationSep 11 2006A 3D stochastic Navier-Stokes equation with a suitable non degenerate additive noise is considered. The regularity in the initial conditions of every Markov transition kernel associated to the equation is studied by a simple direct approach. A by-product ... More
Markov selections for the 3D stochastic Navier-Stokes equationsFeb 27 2006Feb 05 2007We investigate the Markov property and the continuity with respect to the initial conditions (strong Feller property) for the solutions to the Navier-Stokes equations forced by an additive noise. First, we prove, by means of an abstract selection principle, ... More
Electroencephalography source connectivity: toward high time/space resolution brain networksJan 08 2018The human brain is a large-scale network which function depends on dynamic interactions between spatially-distributed regions. In the rapidly-evolving field of network neuroscience, two yet unresolved challenges are potential breakthroughs. First, functional ... More
Asymptotic stability and periodic solutions of vector Liénard equationsAug 18 2010We prove the asymptotic stability of the equilibrium solution of a class of vector Li\'enard equations by means of LaSalle invariance principle. The key hypothesis consists in assuming that the intersections of the manifolds in $\{\dot V = 0\}$ be isolated. ... More
Luminescence and absorption in short period superlatticesApr 04 2018This paper applies analytical approximations for the luminescence of short period semiconductor superlattices and analyses the low density regime, demonstrating that the theory clearly connects with low density absorption with ratios of oscillator strengths ... More
A Table of Derivatives on Arbitrary Time ScalesNov 26 2016This paper presents a collection of useful formulas of dynamic derivatives on time scales, systematically collected for reference purposes. As an application, we define trigonometric and hyperbolic functions on time scales in such a way the most essential ... More
Beukers-like proofs of irrationality for $ζ{(2)}$ and $ζ{(3)}$Aug 12 2013May 13 2016In this note, I develop step-by-step proofs of irrationality for $\,\zeta{(2)}\,$ and $\,\zeta{(3)}$. Though the proofs follow closely those based upon unit square integrals proposed originally by Beukers, I introduce some modifications which certainly ... More
New definite integrals and a two-term dilogarithm identityMar 10 2010Aug 29 2011Among the several proofs known for $\sum_{n=1}^\infty{1/n^2} = {\pi^2/6}$, the one by Beukers, Calabi, and Kolk involves the evaluation of $\,\int_0^1 {\int_0^1{1/(1-x^2 y^2) \, dx} \, dy}$. It starts by showing that this double integral is equivalent ... More
Using known zeta-series to derive the Dancs-He series for $\,\ln{2}\,$ and $\,ζ{(2\,n+1)}$Sep 28 2009Aug 25 2012In a recent work, Dancs and He found new `Euler-type' formulas for $\,\ln{2}\,$ and $\,\zeta{(2\,n+1)}$, $\,n\,$ being a positive integer, each containing a series that apparently can not be evaluated in closed form, distinctly from $\,\zeta{(2\,n)}$, ... More
Relativeca Dopplera efiko inter du akcelataj korpoj - IJan 15 2008Feb 27 2008We describe the Doppler effect between equally accelerated light source and observer under the special relativity. The proper accelerations are constant and parallel. An English version is available by request. - - - - - - - - - - - Ni priskribas luman ... More
Metamagnetism and Lifshitz Transitions in Models for Heavy FermionsMay 25 2012Aug 07 2012We investigate metamagnetic transitions in models for heavy fermions by considering the doped Kondo lattice model in two dimensions. Results are obtained within the framework of dynamical mean field and dynamical cluster approximations. Universal magnetization ... More
Tempa voja^go kaj geodezioj en ^generala relativeco / Time travel and geodesics in general relativityApr 12 2011In the homogeneous metric of Som-Raychaudhuri, in general relativity, we study the three types of geodesics: timelike, null, and spacelike; in particular, the little known geodesics of simultaneities. We also study the non-geodetic circular motion with ... More
Dopplera efiko de luma ebeno vidata per akcelata observantoOct 15 2008A plane lights on monochromatically and immediately after lights off, while an observer starts moving out from the plane, perpendicularly to it, with constant proper acceleration. Special relativity predicts that the observer will see a light circle always ... More
Relativeca Dopplera efekto ĉe unuforme akcelata movo - IJan 08 2007An observer, in rectilinear motion under constant proper acceleration, passes near a source of monochromatic radiation at rest. In the context of special relativity, we describe the observed Doppler effect. We describe also the interesting discontinuous ... More
Doppleraj efikoj ĉe SchwarzschildDec 07 2009Motion of bodies and light rays are studied in the gravitational field of Schwarzschild. Several Doppler effects are described. ----- Movado de korpoj kaj lumo estas studitaj en gravita kampo de Schwarzschild. Pluraj Doppleraj efikoj estas priskribitaj. ... More
Relativistic Doppler effect in a uniformly accelerated motion - IIIAug 01 2008In the context of special relativity, we describe with detail the Doppler effect between a light source at rest and an observer in linear motion and constant proper acceleration. To have an Englis version of this article, ask the authors. ----- ^Ce special-relativeco ... More
Relativeca Dopplera efekto ĉe unuforme akcelata movo -- IIApr 09 2007Extending physics/0701092, a light source of monochromatic radiation, in rectilinear motion under constant proper acceleration, passes near an observer at rest. In the context of special relativity, we describe the observed Doppler effect. We describe ... More
Geodesics of simultaneity in SchwarzschildJun 23 2010Geodesic of simultaneity is a spacelike geodesic in which every pair of neighbour events are simultaneous ($g_{0\mu}\dd x^\mu=0$). These geodesics are studied in the exterior region of \Sch's metric.
La relativeca tempo - I / The relativistic time - IMar 07 2006Jan 04 2012The relativistic time is different from the Newtonian one. We revisit some of these differences in Doppler effect, twin paradox, rotation, rigid rod, and constant proper acceleration. ------- La relativeca tempo estas malsama ol la Newtona. Ni revidos ... More
Algorithm for structure constantsAug 22 2011In a $n$-dimensional Lie algebra, random numerical values are assigned by computer to $n(n-1)$ especially selected structure constants. An algorithm is then created, which calculates without ambiguity the remaining constants, obeying the Jacobi conditions. ... More
La relativeca tempo -- II / The relativistic time -- IIJul 07 2011The theory of relativity showed that several Newtonian ideas about spacetime are imperfect. We present here some relativistic concepts related to these ideas: simultaneity of events and synchronization of clocks (both along a line in the space frame), ... More
Topological Invariant and Quantum Spin Models from Magnetic π Fluxes in Correlated Topological InsulatorsApr 20 2012Feb 28 2013The adiabatic insertion of a \pi flux into a quantum spin Hall insulator gives rise to localized spin and charge fluxon states. We demonstrate that \pi fluxes can be used in exact quantum Monte Carlo simulations to identify a correlated Z_2 topological ... More
Spin observables in pion photoproduction from a unitary and causal effective field theoryDec 29 2010Jan 04 2011Pion photoproduction is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge ... More
Enhanced Cosmic Ray Flux and Ionization for Star Formation in Molecular Clouds Interacting with Supernova RemnantsNov 01 2006Molecular clouds interacting with supernova remnants may be subject to a greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broad-band observations have provided ... More
Diffuse $γ$-ray emission from misaligned active galactic nucleiMay 17 2013We calculate the diffuse $\gamma$-ray emission due to the population of misaligned AGN (MAGN) unresolved by the Large Area Telescope (LAT) on the {\it Fermi} Gamma-ray Space Telescope ({\it Fermi}). A correlation between the $\gamma$-ray luminosity and ... More
Exact results and new insights for models defined over small world networks. First and second order phase transitions. II: ApplicationsJan 23 2008Apr 07 2008We apply a novel method (presented in part I) to solve several small-world models for which the method can be applied analytically: the Viana-Bray model (which can be seen as a 0 or infinite dimensional small-world model), the one-dimensional chain small-world ... More
Detection of Extended Molecular Gas in the Disk of the LSB Galaxy Malin~2Jun 10 2010Our goal is to see if there is molecular gas extending throughout the optical low surface brightness disk of the galaxy Malin 2. We used the heterodyne receiver array (HERA) mounted on the IRAM 30m telecope to make deep observations at the frequency of ... More
Proceedings of the first Congress on North-South collaboration in Physics researchNov 06 2007The first Congress on North-South collaboration in Physics research was held in Oujda Morocco, between April 9th and 13th, 2007. The congress was based on talks giving an overview of relevant subjects both from experiments and theory in all fields of ... More
Particle acceleration close to the supermassive black hole horizon: the case of M87May 27 2008The radio galaxy M87 has recently been found to be a rapidly variable TeV emitting source. We analyze the implications of the observed TeV characteristics and show that it proves challenging to account for them within conventional acceleration and emission ... More
Bethe ansatz solution of discrete time stochastic processes with fully parallel updateNov 22 2004Mar 30 2006We present the Bethe ansatz solution for the discrete time zero range and asymmetric exclusion processes with fully parallel dynamics. The model depends on two parameters: $p$, the probability of single particle hopping, and $q$, the deformation parameter, ... More
Theoretical study of finite temperature spectroscopy in van der Waals clusters. I. Probing phase changes in CaAr_nDec 17 2002The photoabsorption spectra of calcium-doped argon clusters CaAr_n are investigated at thermal equilibrium using a variety of theoretical and numerical tools. The influence of temperature on the absorption spectra is estimated using the quantum superposition ... More
A GPU-Based Genetic Algorithm for the P-Median ProblemOct 31 2016The p-median problem is a well-known NP-hard problem. Many heuristics have been proposed in the literature for this problem. In this paper, we exploit a GPGPU parallel computing platform to present a new genetic algorithm implemented in Cuda and based ... More
The incommensurate charge-density-wave instability in the extended three-band Hubbard modelJul 10 1997The infinite-U three-band Hubbard model is considered in order to describe the CuO_2 planes of the high temperature superconducting cuprates. The charge instabilities are investigated when the model is extended with a nearest-neighbor repulsion between ... More
Thermodynamics of a subensemble of a canonical ensembleJul 07 2009Two approaches to describe the thermodynamics of a subsystem that interacts with a thermal bath are considered. Within the first approach, the mean system energy $E_{S}$ is identified with the expectation value of the system Hamiltonian, which is evaluated ... More
Implications from analyticity constraints used in a Landshoff-Donnachie fitMay 19 2006Landshoff and Donnachie[hep-ph/0509240, (2005)] parametrize the energy behavior of pp and p\bar p scattering cross sections with five parameters, using: \sigma^+=56.08 s^{-0.4525}+21.70s^{0.0808} for pp, \sigma^-=98.39 s^{-0.4525}+21.70s^{0.0808} for ... More
Analyticity as a Robust Constraint on the LHC Cross SectionOct 18 2005Mar 16 2006It is well known that high energy data alone do not discriminate between asymptotic $\ln s$ and $\ln^2s$ behavior of $pp$ and $\bar pp$ cross sections. By exploiting high quality low energy data, analyticity resolves this ambiguity in favor of cross sections ... More
New evidence for the saturation of the Froissart boundJun 03 2005Jun 06 2005Fits to high energy data alone cannot cleanly discriminate between asymptotic $\ln s$ and $\ln^2s$ behavior of total hadronic cross sections. We demonstrate that this is no longer true when we require that these amplitudes also describe, on average, low ... More