Results for "Mendeli H. Vainstein"

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Mixing, ergodicity and slow relaxation phenomenaOct 10 2006Oct 20 2006Investigations on diffusion in systems with memory [I.V.L. Costa, R. Morgado, M.V.B.T. Lima, F.A. Oliveira, Europhys. Lett. 63 (2003) 173] have established a hierarchical connection between mixing, ergodicity, and the fluctuation-dissipation theorem (FDT). ... More
Anomalous diffusion: A basic mechanism for the evolution of inhomogeneous systemsFeb 08 2019In this article we review classical and recent results in anomalous diffusion and provide mechanisms useful for the study of the fundamentals of certain processes, mainly in condensed matter physics, chemistry and biology. Emphasis will be given to some ... More
Disordered Environments in Spatial GamesJul 27 2001The Prisoner's dilemma is the main game theoretical framework in which the onset and maintainance of cooperation in biological populations is studied. In the spatial version of the model, we study the robustness of cooperation in heterogeneous ecosystems ... More
Spatial social dilemmas: dilution, mobility and grouping effects with imitation dynamicsNov 24 2015We present an extensive, systematic study of the Prisoner's Dilemma and Snowdrift games on a square lattice under a synchronous, noiseless imitation dynamics. We show that for both the occupancy of the network and the (random) mobility of the agents there ... More
Percolation and cooperation with mobile agents: Geometric and strategy clustersAug 26 2014We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius rP, which accounts for the population viscosity, and ... More
On the Modeling of Droplet Evaporation on Superhydrophobic SurfacesOct 14 2015When a drop of water is placed on a rough surface, there are two possible extreme regimes of wetting: the one called Cassie-Baxter (CB) with air pockets trapped underneath the droplet and the one characterized by the homogeneous wetting of the surface, ... More
Anomalous DiffusionMay 02 2008May 03 2008Recent investigations call attention to the dynamics of anomalous diffusion and its connection with basic principles of statistical mechanics. We present here a short review of those ideas and their implications.
Spatio-temporal conjecture for diffusionFeb 01 2005We present here a conjecture about the equivalence between the noise density of states of a system governed by a generalized Langevin equation and the fluctuation in the energy density of states in a Hamiltonian system. We present evidence of this for ... More
Does mobility decrease cooperation?Aug 04 2006Sep 12 2006We explore the minimal conditions for sustainable cooperation on a spatially distributed population of memoryless, unconditional strategies (cooperators and defectors) in presence of unbiased, non contingent mobility in the context of the Prisoner's Dilemma ... More
Heterogeneities in systems with quenched disorderApr 10 2003We study the strong role played by structural (quenched) heterogeneities on static and dynamic properties of the Frustrated Ising Lattice Gas in two dimensions, already in the liquid phase. Differently from the dynamical heterogeneities observed in other ... More
Random mobility and spatial structure often enhance cooperationSep 09 2008The effects of an unconditional move rule in the spatial Prisoner's Dilemma, Snowdrift and Stag Hunt games are studied. Spatial structure by itself is known to modify the outcome of many games when compared with a randomly mixed population, sometimes ... More
Khinchin theorem and anomalous diffusionOct 31 2008Dec 10 2008A recent paper [M. H. Lee, Phys. Rev. Lett. 98, 190601 (2007)] has called attention to the fact that irreversibility is a broader concept than ergodicity, and that therefore the Khinchin theorem [A. I. Khinchin, Mathematical Foundations of Statistical ... More
Non-exponential relaxation for anomalous diffusionJan 21 2005May 04 2006We study the relaxation process in normal and anomalous diffusion regimes for systems described by a generalized Langevin equation (GLE). We demonstrate the existence of a very general correlation function which describes the relaxation phenomena. Such ... More
A Simple Non-Markovian Computational Model of the Statistics of Soccer Leagues: Emergence and Scaling effectsJul 08 2012We propose a novel algorithm that outputs the final standings of a soccer league, based on a simple dynamics that mimics a soccer tournament. In our model, a team is created with a defined potential(ability) which is updated during the tournament according ... More
Mixing, Ergodicity and the Fluctuation-Dissipation Theorem in complex systemsJan 19 2005Complex systems such as glasses, gels, granular materials, and systems far from equilibrium exhibit violation of the ergodic hypothesis (EH) and of the fluctuation-dissipation theorem (FDT). Recent investigations in systems with memory have established ... More
Protein motors induced enhanced diffusion in intracellular transportFeb 04 2009Diffusion of transported particles in the intracellular medium is described by means of a generalized diffusion equation containing forces due to the cytoskeleton network and to the protein motors. We find that the enhanced diffusion observed in experiments ... More
Entropic Stochastic ResonanceJul 16 2008We present a novel scheme for the appearance of Stochastic Resonance when the dynamics of a Brownian particle takes place in a confined medium. The presence of uneven boundaries, giving rise to an entropic contribution to the potential, may upon application ... More
Entropy, non-ergodicity and non-Gaussian behaviour in ballistic transportJan 30 2007Ballistic transportation introduces new challenges in the thermodynamic properties of a gas of particles. For example, violation of mixing, ergodicity and of the fluctuation-dissipation theorem may occur, since all these processes are connected. In this ... More
Stochastic description of the dynamics of the random-exchange Heisenberg chainAug 26 2003May 05 2006We study the diffusion process in a Heisenberg chain with correlated spatial disorder, with a power spectrum in the momentum space behaving as $k^{-\beta}$, using a stochastic description. It establishes a direct connection between the fluctuation in ... More
Theory of the Hall Coefficient and the Resistivity on the Layered Organic Superconductors κ-(BEDT-TTF)Nov 20 2000Feb 22 2001In the organic superconducting \kappa-(BEDT-TTF) compounds, various transport phenomena exhibit striking non-Fermi liquid behaviors, which should be the important clues to understanding the electronic state of this system. Especially, the Hall coefficient ... More
Thermodynamical description of modified generalized Chaplygin gas model of dark energyApr 10 2015May 17 2016We consider a universe filled by a modified generalized Chaplygin gas together with a pressureless dark matter component. We get a thermodynamical interpretation for the modified generalized Chaplygin gas confined to the apparent horizon of FRW universe, ... More
Asymptotic function for multi-growth surfaces using power-law noiseNov 06 2002Numerical simulations are used to investigate the multiaffine exponent $\alpha_q$ and multi-growth exponent $\beta_q$ of ballistic deposition growth for noise obeying a power-law distribution. The simulated values of $\beta_q$ are compared with the asymptotic ... More
Study of $Λ$ hypernuclei in the quark mean field modelApr 24 2001Jul 11 2001We extend the quark mean field model to the study of $\Lambda$ hypernuclei. Without adjusting parameters, the properties of $\Lambda$ hypernuclei can be described reasonably well. The small spin-orbit splittings for $\Lambda$ in hypernuclei are achieved, ... More
Comment on `Mathematical structure of the three-dimensional (3D) Ising model'Jul 06 2013The review paper by Zhang Zhi-Dong contains many errors and is based on several earlier works that are equally wrong.
Scalings between Physical and their Observationally related Quantities of Merger RemnantsSep 07 2005We present scaling relations between the virial velocity (V) and the one-dimensional central velocity dispersion (Sig0); the gravitational radius (Rv) and the effective radius (Re); and the total mass (M) and the luminous mass (ML) found in N-body simulations ... More
Rhythmic cluster generation in strongly driven colloidal dispersionsJun 28 2006We study the response of a nematic colloidal dispersion of rods to a driven probe particle which is dragged with high speed through the dispersion perpendicular to the nematic director. In front of the dragged particle, clusters of rods are generated ... More
Emergent states in dense systems of active rods: from swarming to turbulenceApr 02 2012Dense suspensions of self-propelled rod-like particles exhibit a fascinating variety of non-equilibrium phenomena. By means of computer simulations of a minimal model for rigid self-propelled colloidal rods with variable shape we explore the generic diagram ... More
Aggregation of self-propelled colloidal rods near confining wallsSep 03 2008Non-equilibrium collective behavior of self-propelled colloidal rods in a confining channel is studied using Brownian dynamics simulations and dynamical density functional theory. We observe an aggregation process in which rods self-organize into transiently ... More
How to capture active particlesFeb 01 2012For many applications, it is important to catch collections of autonomously navigating microbes and man-made microswimmers in a controlled way. Here we propose an efficient trap to collectively capture self-propelled colloidal rods. By means of computer ... More
Cooperative single-photon subradiant states in a three-dimensional atomic arrayJun 21 2016We propose a complete superradiant and subradiant states that can be manipulated and prepared in a three-dimensional atomic array. These subradiant states can be realized by absorbing a single photon and imprinting the spatially-dependent phases on the ... More
Effects of Spin Fluctuations in Quasi-One-Dimensional Organic SuperconductorsMay 05 1999We study the electronic states of quasi-one-dimensional organic conductors using the single band Hubbard model at half-filling. We treat the effects of the on-site Coulomb interaction by the fluctuation-exchange (FLEX) method, and calculate the phase ... More
Application of the Limit Cycle Model to Star Formation Histories in Spiral Galaxies: Variation among Morphological TypesMay 04 2000We propose a limit-cycle scenario of star formation history for any morphological type of spiral galaxies. It is known observationally that the early-type spiral sample has a wider range of the present star formation rate (SFR) than the late-type sample. ... More
On the extrapolation of perturbation seriesDec 21 2002We discuss certain special cases of algebraic approximants that are given as zeroes of so-called "effective characteristic polynomials" and their generalization to a multiseries setting. These approximants are useful for the convergence acceleration or ... More
The size-extensitivity of correlation energy estimators based on effective characteristic polynomialsApr 08 1997Estimators $\Pi n$ for the correlation energy can be computed as roots of effective characteristic polynomials of degree $n$. The coefficients of these polynomials are derived from the terms of the perturbation series of the energy. From a fourth-order ... More
Integrability and Canonical Structure of d=2, N=16 SupergravityApr 23 1998Jul 01 1998The canonical formulation of d=2, N=16 supergravity is presented. We work out the supersymmetry generators (including all higher order spinor terms) and the N=16 superconformal constraint algebra. We then describe the construction of the conserved non-local ... More
A focusable, convergent fast-electron beam from ultra-high-intensity laser-solid interactionsJan 29 2015A novel scheme for the creation of a convergent, or focussing, fast-electron beam generated from ultra-high-intensity laser-solid interactions is described. Self-consistent particle-in-cell simulations are used to demonstrate the efficacy of this scheme ... More
Quark mean field model for nuclear matter and finite nucleiNov 15 1999We study nuclear matter and finite nuclei in terms of the quark mean field (QMF) model, in which we describe the nucleon using the constituent quark model. The meson mean fields, in particular the sigma meson, created by other nucleons act on quarks inside ... More
The relativistic two-body potentials of constraint theory from summation of Feynman diagramsFeb 07 1996The relativistic two-body potentials of constraint theory for systems composed of two spin-0 or two spin-1/2 particles are calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates them to the scattering amplitude. ... More
Superradiant cascade emissions in an atomic ensemble via four-wave mixingJan 21 2015May 04 2015We investigate superradiant cascade emissions from an atomic ensemble driven by two-color classical fields. The correlated pair of photons (signal and idler) is generated by adiabatically driving the system with large-detuned light fields via four-wave ... More
Spectral analysis for cascade-emission-based quantum communication in atomic ensemblesMar 11 2014The ladder configuration of atomic levels provides a source for telecom photons (signal) from the upper atomic transition. \ For rubidium and cesium atoms, the signal field has the range around 1.3-1.5 $\mu$m that can be coupled to an optical fiber and ... More
Positive-P phase space method simulation in superradiant emission from a cascade atomic ensembleJan 12 2012The superradiant emission properties from an atomic ensemble with cascade level configuration is numerically simulated. The correlated spontaneous emissions (signal then idler fields) are purely stochastic processes which are initiated by quantum fluctuations. ... More
AdS/CFT correspondence in the Euclidean contextNov 02 2006May 23 2007We study two possible prescriptions for AdS/CFT correspondence by means of functional integrals. The considerations are non-perturbative and reveal certain divergencies which turn out to be harmless, in the sense that reflection-positivity and conformal ... More
Correlation Energy Estimators based on Møller-Plesset Perturbation TheoryMar 05 1996Some methods for the convergence acceleration of the M{\o}ller-Plesset perturbation series for the correlation energy are discussed. The order-by-order summation is less effective than the Feenberg series. The latter is obtained by renormalizing the unperturbed ... More
N=8 matter coupled AdS_3 supergravitiesJun 18 2001Following the recent construction of maximal (N=16) gauged supergravity in three dimensions, we derive gauged D=3, N=8 supergravities in three dimensions as deformations of the corresponding ungauged theories with scalar manifolds SO(8,n)/(SO(8)x SO(n)). ... More
Maximal gauged supergravity in three dimensionsOct 11 2000Jan 07 2001We construct maximally supersymmetric gauged N=16 supergravity in three dimensions, thereby obtaining an entirely new class of AdS supergravities. These models are not derivable from any known higher-dimensional theory, indicating the existence of a new ... More
Whitham Prepotential and SuperpotentialDec 30 2003Jan 24 2004N=2 supersymmetric U(N) Yang-Mills theory softly broken to N=1 by the superpotential of the adjoint scalar fields is discussed from the viewpoint of the Whitham deformation theory for prepotential. With proper identification of the superpotential we derive ... More
Surface anisotropy in nanomagnets: transverse or Néel ?Jul 17 2003Mar 31 2004Through the hysteresis loop and magnetization spatial distribution we study and compare two models for surface anisotropy in nanomagnets: a model with transverse anisotropy axes and N\'eel's model. While surface anisotropy in the transverse model induces ... More
String-Scale BaryogenesisMar 25 1997Mar 26 1997Baryogenesis scenarios at the string scale are considered. The observed baryon to entropy ratio, $n_B /s \sim 10^{-10}$, can be explained in these scenarios.
Thermodynamic of universe with a varying dark energy componentMay 04 2015Aug 03 2015We consider a FRW universe filled by a dark energy candidate together with other possible sources which may include the baryonic and non-baryonic matters. Thereinafter, we consider a situation in which the cosmos sectors do not interact with each other. ... More
Analysis of the thermal cross section of the capture reaction 13C(n,gamma)14COct 02 1997We investigate the thermal cross section of the reaction 13C(n,gamma)14}C which takes place in the helium burning zones of red giant star as well as in the nucleosynthesis of Inhomogeneous Big Bang models. We find that we can reproduce the experimentally ... More
The two-fermion vector potential of constraint theory from Feynman diagramsOct 16 1995The relativistic fermion-antifermion bound state vector potential of constraint theory is calculated, in perturbation theory, by means of the Lippmann-Schwinger type equation that relates it to the scattering amplitude. Leading contributions of n-photon ... More
Energy and decay width of the pi-K atomMay 24 2006The energy and decay width of the pi-K atom are evaluated in the framework of the quasipotential-constraint theory approach. The main electromagnetic and isospin symmetry breaking corrections to the lowest-order formulas for the energy shift from the ... More
Molecular dynamics simulation of aging in amorphous silicaDec 06 1999By means of molecular dynamics simulations we examine the aging process of a strong glass former, a silica melt modeled by the BKS potential. The system is quenched from a temperature above to one below the critical temperature, and the potential energy ... More
An indefinite metric model for interacting quantum fields with non-stationary background gravitationAug 25 2004We consider a relativistic Ansatz for the vacuum expectation values (VEVs) of a quantum field on a globally hyperbolic space-time which is motivated by certain Euclidean field theories. The Yang-Feldman asymptotic condition w.r.t. a "in"-field in a quasi-free ... More
Series Prediction based on Algebraic ApproximantsJul 12 2011It is described how the Hermite-Pad\'e polynomials corresponding to an algebraic approximant for a power series may be used to predict coefficients of the power series that have not been used to compute the Hermite-Pad\'e polynomials. A recursive algorithm ... More
Boundary blow-up solutions of elliptic equations involving regional fractional LaplacianFeb 09 2016In this paper, we study existence of boundary blow-up solutions for elliptic equations involving regional fractional Laplacian. We also discuss the optimality of our results.
A 5D noncompact Kaluza -Klein cosmology in the presence of Null perfect fluidMay 18 2010Jun 08 2011For the description of the early inflation, and acceleration expansion of the Universe, compatible with observational data, the 5D noncompact Kaluza--Klein cosmology is investigated. It is proposed that the 5D space is filled with a null perfect fluid, ... More
Schwinger-Dyson and Large $N_{c}$ Loop Equation for Supersymmetric Yang-Mills TheoryApr 04 1996We derive an infinite sequence of Schwinger-Dyson equations for $N=1$ supersymmetric Yang-Mills theory. The fundamental and the only variable employed is the Wilson-loop geometrically represented in $N=1$ superspace: it organizes an infinite number of ... More
On pseudo B-Weyl operators and generalized Drazin invertibility for operator matricesMar 23 2015We introduce a new class which generalizes the class of B-Weyl operators. We say that $T\in L(X)$ is pseudo B-Weyl if $T=T_1\oplus T_2$ where $T_1$ is a Weyl operator and $T_2$ is a quasi-nilpotent operator. We show that the corresponding pseudo B-Weyl ... More
The infinite mass limit of the two-particle Green's function in QEDApr 07 1997The behavior of the two-particle Green's function in QED is analyzed in the limit when one of the particles becomes infinitely massive. It is found that the dependences of the Green's function on the relative times of the ingoing and outgoing particles ... More
Incorporation of anomalous magnetic moments in the two-body relativistic wave equations of constraint theoryJun 19 1996Using a Dirac-matrix substitution rule, applied to the electric charge, the anomalous magnetic moments of fermions are incorporated in local form in the two-body relativistic wave equations of constraint theory. The structure of the resulting potential ... More
The Early History of the Integrable Chiral Potts Model and the Odd-Even ProblemNov 26 2015Jan 18 2016In the first part of this paper I shall discuss the round-about way of how the integrable chiral Potts model was discovered about 30 years ago. As there should be more higher-genus models to be discovered, this might be of interest. In the second part ... More
The nature of the line profile variability in the spectrum of the massive binary HD 152219May 08 2009Jun 10 2009HD 152219 is a massive binary system with O9.5 III + B1-2 V/III components and a short orbital period of 4.2 d. Its primary component further displays clear line profile variability (LPV). The primary component being located within the pulsational instability ... More
Exploring the cooperative regimes in a model of agents without memory or "tags": indirect reciprocity vs. selfish incentivesNov 15 2002The self-organization in cooperative regimes in a simple mean-field version of a model based on "selfish" agents which play the Prisoner's Dilemma (PD) game is studied. The agents have no memory and use strategies not based on direct reciprocity nor 'tags'. ... More
Lagrangian Description, Symplectic Structure, and Invariants of 3D Fluid FlowMar 24 1997Three dimensional unsteady flow of fluids in the Lagrangian description is considered as an autonomous dynamical system in four dimensions. The condition for the existence of a symplectic structure on the extended space is the frozen field equations of ... More
Stiff quantum polymersOct 19 2009At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the second and fourth moments of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.
Stiff Quantum PolymersJan 02 2007May 01 2007At ultralow temperatures, polymers exhibit quantum behavior, which is calculated here for the moments <R^2> and <R^4> of the end-to-end distribution in the large-stiffness regime. The result should be measurable for polymers in wide optical traps.
Experimental Test for Absence of R-Term in Schroedinger Equation in Curved SpaceOct 29 2000Nov 12 2000We point out that the presence of a term proportional to the scalar curvature in the Schroedinger equation in curved space can easily be detected in atomic spectra with Russel-Saunders coupling by a violation of the Lande interval rule for adjacent levels ... More
Pressure of Membrane between WallsNov 21 1998May 04 1999For a single membrane of stiffness kappa fluctuating between two planar walls of distance d, we calculate analytically the proportionality constant in the pressure law p proportional to T^2/kappa^2 d^3, in very good agreement with results from Monte Carlo ... More
Universality Principle for Orbital Angular Momentum and Spin in Gravity with TorsionJul 09 1998Jul 11 1998We argue that compatibility with elementary particle physics requires gravitational theories with torsion to be unable to distinguish between orbital angular momentum and spin. An important consequence of this principle is that spinless particles must ... More
Classical and Fluctuating Paths in Spaces with Curvature and TorsionJun 03 1996Aug 08 1996This conference talk elaborates on a recently discovered mapping procedure by which classical orbits and path integrals for the motion of a point particle in flat space can be transformed correctly into those in curved space. This procedure evolved from ... More
New Gauge Symmetry in Gravity and the Evanescent Role of TorsionMay 10 2010Jun 08 2010If the Einstein-Hilbert action ${\cal L}_{\rm EH}\propto R$ is re-expressed in Riemann-Cartan spacetime using the gauge fields of translations, the vierbein field $h^\alpha{}_\mu$, and the gauge field of local Lorentz transformations, the spin connection ... More
Recent Physics At COSY--A ReviewMay 04 2005The COSY accelerator in J\"{u}lich is presented together with its internal and external detectors. The physics program performed recently is discussed with emphasis on strangeness physics and precision experiments.
The importance of nuclear masses in the astrophysical rp-processJul 27 2006The importance of mass measurements for astrophysical capture processes in general, and for the rp-process in X-ray bursts in particular is discussed. A review of the current uncertainties in the effective lifetimes of the major waiting points 64Ge, 68Se, ... More
Super--Lax Operator Embedded in Self--Dual Supersymmetric Yang--Mills TheoryNov 01 1993We show that the super-Lax operator for $~N=1$~ supersymmetric Kadomtsev-Petviashvili equation of Manin and Radul in three-dimensions can be embedded into recently developed self-dual supersymmetric Yang-Mills theory in $~2+2\-$dimensions, based on general ... More
Supersymmetric KP Systems Embedded in Supersymmetric Self-Dual Yang-Mills TheoryMar 15 1993We show that $~N=1$~ {\it supersymmetric} Kadomtsev-Petviashvili (SKP) equations can be embedded into recently formulated $~N=1$~ self-dual {\it supersymmetric} Yang-Mills theories after appropriate dimensional reduction and truncation, which yield three-dimensional ... More
Finite-size effects in the spherical model of finite thicknessMay 06 2008Aug 12 2008A detailed analysis of the finite-size effects on the bulk critical behaviour of the $d$-dimensional mean spherical model confined to a film geometry with finite thickness $L$ is reported. Along the finite direction different kinds of boundary conditions ... More
Hawking Radiation of Warped Anti de Sitter and Rotating Hairy Black Holes with Scalar HairDec 11 2015This thesis mainly focuses on the Hawking radiation (HR) evacuating from the surface of the objects that have earned a reputation as the most extraordinary objects existing so far; the black holes (BHs). Throughout this study, quantum tunneling (QT) process ... More
The Cluster Mass Function from Weak Gravitational LensingAug 23 2006We present the first measurement of the mass function of galaxy clusters based directly on cluster masses derived from observations of weak gravitational lensing. To investigate the degree of sample incompleteness resulting from the X-ray based selection ... More
Weighing 40 X-ray Luminous Clusters of Galaxies with Weak Gravitational LensingSep 25 2000Deep two-color imaging of 40 clusters of galaxies with the NOT and the University of Hawaii 2.24-m telescope is used to measure the weak gravitational shear acting on faint background galaxies. From this, maps of the projected cluster mass distribution ... More
A compilation of weak gravitational lensing studies of clusters of galaxiesJan 21 2007We present a list of clusters that have had their dark matter content measured using weak gravitational lensing. The list consists of 139 clusters, with weak lensing measurements reported in 64 different publications. Details are provided about the selection ... More
Frustrated Systems: Ground State Properties via Combinatorial OptimizationMay 01 1997An introduction to the application of combinatorial optimization methods to ground state calculations of frustrated, disordered systems is given. We discuss the interface problem in the random bond Ising ferromagnet, the random field Ising model, the ... More
Nonabelian gauge field dynamics on matrix D-branesDec 11 1996May 14 1997We construct a calculational scheme for handling the matrix ordering problems connected with the appearance of D-brane positions taking values in the same Lie algebra as the nonabelian gauge field living on the D-brane. The formalism is based on the use ... More
On scheme dependence of gravitational dressing of renormalization group functionsDec 05 1995It is shown that for 2D field theories only the first order coefficient of the gravitationally dressed RG $\beta$-function is scheme independent. This is valid even for matter theories with one dimensionless coupling, where the first two coefficients ... More
The Search for the QGP: A Critical AppraisalSep 08 2000Over the past 15 years, an extensive program of high energy nuclear collisions at BNL and CERN has been devoted to the experimental search for the quark-gluon plasma predicted by QCD. The start of RHIC this year will increase the highest available collision ... More
Phase Transitions in QCDJul 19 2000At high temperatures or densities, hadronic matter shows different forms of critical behaviour: colour deconfinement, chiral symmetry restoration, and diquark condensation. I first discuss the conceptual basis of these phenomena and then consider the ... More
Insights and puzzles in particle physicsOct 15 2014I briefly review the conceptual developments that led to the Standard Model and discuss some of its remarkable qualitative features. On the way, I draw attention to several puzzling aspects that are beyond the reach of our present understanding of the ... More
The mass of the two lightest quarksMay 29 2013The problems encountered in the determination of m_u and m_d are discussed. While their sum is known quite well, the difference m_d-m_u, which measures the breaking of isospin symmetry in the QCD Lagrangian, is still subject to significant uncertainties. ... More
pi-pi scattering: theory is ahead of experimentDec 20 2002I draw attention to a recent breakthrough in the field of low energy pion physics: the consequences of the hidden symmetry of the QCD Hamiltonian have successfully been incorporated in the general dispersive framework for the pi-pi scattering amplitude, ... More
Phonons as Goldstone BosonsSep 25 1996The implications of the hidden, spontaneously broken symmetry for the properties of the sound waves of a solid are analyzed. Although the discussion does not go beyond standard wisdom, it presents some of the known results from a different perspective. ... More
The Masses of the Light QuarksFeb 08 1996Talk given at the Conference on Fundamental Interactions of Elementary Particles, ITEP, Moscow, Oct. 1995. The paper reviews the current status of knowledge concerning m_u, m_d and m_s. Qualitative aspects of the resulting picture for the breaking of ... More
Theoretical aspects of Chiral DynamicsOct 26 2015Nov 03 2015Many of the quantities of interest at the precision frontier in particle physics require a good understanding of the strong interaction at low energies. The present talk reviews the theoretical framework used in this context. In particular, I draw attention ... More
Strong Interactions at Low EnergyDec 20 2002The lectures review some of the basic concepts relevant for an understanding of the low energy properties of the strong interactions: chiral symmetry, spontaneous symmetry breakdown, Goldstone bosons, quark condensate. The effective field theory used ... More
Dust-to-Gas Ratio and Metallicity in Dwarf GalaxiesMar 22 1999We examine the dust-to-gas ratio as a function of metallicity for dwarf galaxies [dwarf irregular galaxies (dIrrs) and blue compact dwarf galaxies (BCDGs)]. Using a one-zone model and adopting the instantaneous recycling approximation, we prepare a set ... More
Canonical Quantization of (2+1)-Dimensional GravityJan 20 1994We consider the quantum dynamics of both open and closed two- dimensional universes with ``wormholes'' and particles. The wave function is given as a sum of freely propagating amplitudes, emitted from a network of mapping class images of the initial state. ... More
AdS/CFT without holography: A hidden dimension on the CFT side and implications for black-hole entropyJul 02 2015We propose a new non-holographic formulation of AdS/CFT correspondence, according to which quantum gravity on AdS and its dual non-gravitational field theory both live in the same number D of dimensions. The field theory, however, appears (D-1)-dimensional ... More
Gravitational crystal inside the black holeMay 15 2015Sep 08 2015Crystals, as quantum objects typically much larger than their lattice spacing, are a counterexample to a frequent prejudice that quantum effects should not be pronounced at macroscopic distances. We propose that the Einstein theory of gravity only describes ... More
The trivial solution of the gravitational energy-momentum tensor problemJul 30 2014Aug 07 2014In the literature one often finds the claim that there is no such thing as an energy-momentum tensor for the gravitational field, and consequently, that the total energy-momentum conservation can only be defined in terms of a gravitational energy-momentum ... More
EPR before EPR: a 1930 Einstein-Bohr thought experiment revisitedMar 06 2012May 28 2012In 1930 Einstein argued against consistency of the time-energy uncertainty relation by discussing a thought experiment involving a measurement of mass of the box which emitted a photon. Bohr seemingly triumphed over Einstein by arguing that the Einstein's ... More
Solipsistic hidden variablesDec 09 2011Jan 07 2013We argue that it is logically possible to have a sort of both reality and locality in quantum mechanics. To demonstrate this, we construct a new quantitative model of hidden variables (HV's), dubbed solipsistic HV's, that interpolates between the orthodox ... More