Results for "F. Amiranoff"

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From quantum to classical modelling of radiation reaction: a focus on the radiation spectrumFeb 08 2018Soon available multi petawatt ultra-high-intensity (UHI) lasers will allow us to probe high-amplitude electromagnetic fields interacting with either ultra-relativistic electron beams or hot plasmas in the so-called moderately quantum regime. The correct ... More
Search for Stimulated Photon-Photon Scattering in VacuumJul 01 2010We have searched for stimulated photon scattering in vacuum at a center of mass photon energy of 0.8 eV. The QED contribution to this process is equivalent to four wave mixing in vacuum. No evidence for gamma-gamma scattering was observed. The corresponding ... More
Joule-level high effiency energy transfer to sub-picosecond laser pulses by a plasma-based amplifierDec 21 2018Laser plasma amplification of sub-picosecond pulses above the Joule level is demonstrated, a major milestone for this scheme to become a solution for the next-generation of ultra-high intensity lasers. By exploring over 6 orders of magnitude the influence ... More
A summary of the beatwave experiments at Ecole PolytechniqueSep 12 2007We present a summary of the beatwave particle acceleration program developed at Ecole Polytechnique. In dedicated experiments, plasma formation, plasma wave generation and saturation, and particle acceleration were successively studied and understood ... More
Radiation Pressure Driven Ion Weibel Instability and Collisionless ShocksMay 15 2017Aug 11 2017The Weibel instability from counterstreaming plasma flows is a basic process highly relevant for collisionless shock formation in astrophysics. In this Letter we investigate, via two- and three- dimensional simulations, suitable configurations for laboratory ... More
No light shining through a wall : new results from a photoregeneration experimentJul 09 2007Oct 22 2007Recently, axion-like particle search has received renewed interest. In particular, several groups have started ``light shining through a wall'' experiments based on magnetic field and laser both continuous, which is very demanding in terms of detector ... More
Search for photon oscillations into massive particlesAug 20 2008In this paper, we present the final results of our experiment on photon-axion oscillations in the presence of a magnetic field, which took place at LULI (Laboratoire pour l'Utilisation des Lasers Intenses, Palaiseau, France). Our null measurement allowed ... More
Model pseudofermionic systems: connections with exceptional pointsFeb 25 2014We discuss the role of pseudo-fermions in the analysis of some two-dimensional models, recently introduced in connection with non self-adjoint hamiltonians. Among other aspects, we discuss the appearance of exceptional points in connection with the validity ... More
The acoustic spectrum of alpha Cen AJun 04 2002This paper presents the analysis of Doppler p-mode observations of the G2V star $\alpha$ Cen A obtained with the spectrograph CORALIE in May 2001. Thirteen nights of observations have made it possible to collect 1850 radial velocity measurements with ... More
PINGSoft: an IDL visualisation and manipulation tool for Integral Field Spectroscopic dataJun 04 2010In this article we introduce PINGSoft, a set of IDL routines designed to visualise and manipulate, in an interactive and friendly way, Integral Field Spectroscopic data. The package is optimised for large databases and a fast visualisation rendering. ... More
Spin, charge and single-particle spectral functions of the one-dimensional quarter filled Holstein modelJul 15 2008Sep 30 2008We use a recently developed extension of the weak coupling diagrammatic determinantal quantum Monte Carlo method to investigate the spin, charge and single particle spectral functions of the one-dimensional quarter-filled Holstein model with phonon frequency ... More
Upper and lower limits for the number of S-wave bound states in an attractive potentialOct 25 2002New upper and lower limits are given for the number of S-wave bound states yielded by an attractive (monotonic) potential in the context of the Schrodinger or Klein-Gordon equation.
Velocity-Space Diffusion in a Perpendicularly Propagating Electrostatic WaveJan 07 2005The motion of ions in the fields B = B_0 zhat and E = E_0 yhat cos(k_perp y - omega t) is considered. When omega >> Omega_i and v_perp > omega/k_perp, the equations of motion may be reduced to a set of difference equations. These equations exhibit stochastic ... More
Minimal Length Uncertainty Relation and gravitational quantum wellMay 18 2006The dynamics of a particle in a gravitational quantum well is studied in the context of nonrelativistic quantum mechanics with a particular deformation of a two-dimensional Heisenberg algebra. This deformation yields a new short-distance structure characterized ... More
Existence of mesons after deconfinementJun 27 2007Oct 24 2007We investigate the possibility for a quark-antiquark pair to form a bound state at temperatures higher than the critical one ($T>T_c$), thus after deconfinement. Our main goal is to find analytical criteria constraining the existence of such mesons. Our ... More
On the premelting features in sodium clustersDec 08 2003Melting in Na_n clusters described with an empirical embedded-atom potential has been reexamined in the size range 55<=n<=147 with a special attention at sizes close to 130. Contrary to previous findings, premelting effects are also present at such medium ... More
Interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs in Brans-Dicke cosmologyAug 29 2015Sep 29 2016In the framework of Brans-Dicke cosmology, we have studied the interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs. The Brans-Dicke parameter is investigated versus the conditions for the acceleration ... More
Distances in plane membranesNov 13 2001Dec 27 2001A flat membrane with given shape is displayed; two points in the membrane are randomly selected; the probability that the separation between the points have a specified value is sought. A simple method to evaluate the probability density is developed, ... More
Cosmic crystallography: the hyperbolic isometriesOct 29 2000All orientation preserving isometries of the hyperbolic three-space are studied, and the probability density of conjugate pair separations for each isometry is presented. The study is relevant for the cosmic crystallography, and is the theoretical counterpart ... More
The ideal relativistic spinning gas: polarization and spectraOct 30 2007Feb 22 2008We study the physics of the ideal relativistic rotating gas at thermodynamical equilibrium and provide analytical expressions of the momentum spectra and polarization vector for the case of massive particles with spin 1/2 and 1. We show that the finite ... More
Reply to "Comment on 'Quantum massive conformal gravity' by F. F. Faria"Aug 03 2016Recently in Eur. Phys. J. C 76, 341 (2016) [arXiv:1604.08706] Myung has suggested that the problem with unphysical states in massive conformal gravity, which was pointed in Eur. Phys. J. C 76, 188 (2016), is solved if we quantize the dilaton field in ... More
Quantum massive conformal gravityMar 14 2015Apr 07 2016We first find the linear approximation of the second plus fourth order derivative massive conformal gravity action. Then we reduce the linearized action to separated second order derivative terms, which allows us to quantize the theory by using the standard ... More
Massive conformal gravityDec 19 2013Dec 15 2014In this article we construct a massive theory of gravity that is invariant under conformal transformations. The massive action of the theory depend on the metric tensor and a scalar field, which are considered as the only field variables. We find the ... More
Solar system tests for linear massive conformal gravityApr 08 2016We first find the linearized gravitational field of a static spherically symmetric mass distribution in massive conformal gravity. Then we test this field with two solar system experiments: deflection of light by the sun and radar echo delay. The result ... More
Funciones de Green para Ecuaciones Diferenciales con InvolucionesNov 20 2014In this work we revise the most recent developments concerning the study of first order problems regarding differential equations with involutions. We take into account two cases: the case of initial conditions and constant coefficients and the case of ... More
Conformal theory of everythingMar 09 2019By using conformal symmetry we unify the standard model of particle physics with gravity in a consistent quantum field theory which describes all the fundamental particles and forces of nature.
Comment on "Astrophysical gravitational waves in conformal gravity"Feb 15 2019Recently, in Phys. Rev. D 98, 084002 (2018), an investigation was carried out on the gravitational radiation from binary systems in conformal gravity and massive conformal gravity. According to the authors of the paper, these two theories differ only ... More
Depleted Kondo LatticesApr 07 2001Nov 17 2001We consider a two dimensional Kondo lattice model with exchange J and hopping t in which three out of four impurity spins are removed in a regular way. At the particle-hole symmetric point the model may be studied with auxiliary field quantum Monte Carlo ... More
The interplay between d-wave superconductivity and antiferromagnetic fluctuations: a quantum Monte Carlo studyJun 25 1998We consider the repulsive Hubbard model on a square lattice with an additional term, W, which depends upon the square of a single-particle nearest-neighbor hopping. At half-band filling, constant W, we show that enhancing U/t drives the system from a ... More
Superconductors as ideal spin sources for spintronicsNov 05 2007Apr 03 2008Spin-polarized transport is investigated in normal metal-superconductor (NS) junctions as a function of interface transmissivity as well as temperature when the density of states of a superconductor is Zeeman-split in response to an exchange field (h_exc). ... More
Ultra-High-Energy Cosmic Rays from the Radio Lobes of AGNsSep 22 2008In the past year, the HiRes and Auger collaborations have reported the discovery of a high-energy cutoff in the ultra-high energy cosmic-ray (UHECR) spectrum, and an apparent clustering of the highest energy events towards nearby active galactic nuclei ... More
Sampling exactly from the normal distributionMar 25 2013Jun 10 2014An algorithm for sampling exactly from the normal distribution is given. The algorithm reads some number of uniformly distributed random digits in a given base and generates an initial portion of the representation of a normal deviate in the same base. ... More
Transverse Mercator with an accuracy of a few nanometersFeb 08 2010Feb 03 2011Implementations of two algorithms for the transverse Mercator projection are described; these achieve accuracies close to machine precision. One is based on the exact equations of Thompson and Lee and the other uses an extension of Krueger's series for ... More
Quaternions in molecular modelingJun 23 2005Apr 04 2006Quaternions are an important tool to describe the orientation of a molecule. This paper considers the use of quaternions in matching two conformations of a molecule, in interpolating rotations, in performing statistics on orientational data, in the random ... More
Long-Time Correlations in Stochastic SystemsJan 11 2005In recent years, there has been considerable interest in understanding the motion in Hamiltonian systems when phase space is divided into stochastic and integrable regions. This paper studies one aspect of this problem, namely, the motion of trajectories ... More
Contraction Elimination in Sequent Based Ground Equational CalculusDec 30 2015In "Cut Elimination for Gentzen's Sequent Calculus with Equality and Logic of Partial Terms" LNCS 7750,161-172(2013), we have shown that the cut rule is eliminable in two ground equational sequent calculi, to be denoted by EQ_M and EQ'. In this note we ... More
Exchange Monte Carlo for Molecular Simulations with Monoelectronic HamiltoniansMar 04 2002We introduce a general Monte Carlo scheme for achieving atomistic simulations with monoelectronic Hamiltonians including the thermalization of both nuclear and electronic degrees of freedom. The kinetic Monte Carlo algorithm is used to obtain the exact ... More
PINGSoft 2: an IDL Integral Field Spectroscopy Software, ready for the CALIFA survey dataNov 01 2012PINGSoft, is a set of IDL routines designed to visualise, manipulate, and analyse integral field spectroscopy (IFS) data regardless of the original instrument and spaxel shape. PINGSoft 2 is a relatively major upgrade with respect to the first version: ... More
Computation of Green's functions through algebraic decomposition of operatorsJul 04 2017In this article we use linear algebra to improve the computational time for the obtaining of Green's functions of linear differential equations with reflection (DER). This is achieved by decomposing both the `reduced' equation (the ODE associated to a ... More
Two- and three- dimensional few-body systems in the universal regimeNov 11 2014Macro properties of cold atomic gases are driven by few-body correlations, even if the gas has thousands of particles. Quantum systems composed of two and three particles with attractive zero\=/range pairwise interactions are considered for general masses ... More
SU(2)-spin Invariant Auxiliary Field Quantum Monte Carlo Algorithm for Hubbard modelsJun 25 1998Auxiliary field quantum Monte Carlo methods for Hubbard models are generally based on a Hubbard-Stratonovitch transformation where the field couples to the z-component of the spin. This transformation breaks SU(2) spin invariance. The symmetry is restored ... More
Adiabatic Magnetization of Superconductors as a High-Performance Cooling MechanismNov 25 2008The adiabatic magnetization of a superconductor is a cooling principle proposed in the 30s, which has never been exploited up to now. Here we present a detailed dynamic description of the effect, computing the achievable final temperatures as well as ... More
Hybrid superconducting quantum magnetometerMar 18 2011Dec 03 2011A superconducting quantum magnetometer based on magnetic flux-driven modulation of the density of states of a proximized metallic nanowire is theoretically analyzed. With optimized geometrical and material parameters transfer functions up to a few mV/Phi_0 ... More
Long-Time Correlations in the Stochastic RegimeJan 11 2005The phase space for Hamiltonians of two degrees of freedom is usually divided into stochastic and integrable components. Even when well into the stochastic regime, integrable orbits may surround small stable regions or islands. The effect of these islands ... More
Temporal Evolution of Lower Hybrid Waves in the Presence of Ponderomotive Density FluctuationsJan 10 2005The propagation of lower hybrid waves in the presence of ponderomotive density fluctuations is considered. The problem is treated in two dimensions and, in order to be able to correctly impose the boundary conditions, the waves are allowed to evolve in ... More
Algorithms for geodesicsSep 21 2011Mar 28 2012Algorithms for the computation of geodesics on an ellipsoid of revolution are given. These provide accurate, robust, and fast solutions to the direct and inverse geodesic problems and they allow differential and integral properties of geodesics to be ... More
Stochastic Optimal Control with Delay in the Control I: solving the HJB equation through partial smoothingJul 21 2016Stochastic optimal control problems governed by delay equations with delay in the control are usually more difficult to study than the the ones when the delay appears only in the state. This is particularly true when we look at the associated Hamilton-Jacobi-Bellman ... More
Experimentally obtaining metrics in general relativityMay 10 2005It seems to be not well known that the metrics of general relativity (GR) can be obtained without integrating Einstein equations. To that, we need only define a unit for GR-interval $\Delta s$, and observe 10 geodesics (out of which at least one must ... More
Right-Left Asymmetry of Radiation from FissionOct 09 2007The effect of the right-left asymmetry is considered in the predicted earlier electric dipole radiation from fission fragments arising due to the Strutinski-Denisov induced polarisation mechanism. The magnitude of the asymmetry parameter is on the level ... More
Gas accretion on spiral galaxies: bar formation and renewalJun 17 2002The effects of gas accretion on spiral disk dynamics and stability are studied through N-body simulations, including star formation and gas/stars mass exchange. The detailed processes of bar formation, bar destruction and bar re-formation are followed, ... More
Formation of polar ring galaxiesJan 20 2003Feb 04 2003Polar ring galaxies are peculiar systems in which a gas rich, nearly polar ring surrounds an early-type or elliptical host galaxy. Two formation scenarios for these objects have been proposed: they are thought to form either in major galaxy mergers or ... More
A new geometrical approach to metric-affine gravityJul 16 2013Here we consider a metric-affine theory of gravity in which the gravitational Lagrangian is the scalar curvature. The matter action is allowed to depend also on the torsion and the nonmetricity, which are considered as the field variables together with ... More
Cosmology in massive conformal gravityOct 19 2014Sep 25 2015In this article we find the cosmological solutions of the massive conformal gravity field equations in the presence of matter fields. In particular, we show that the solution of negative spatial curvature is in good agreement with our universe.
FCNC production of same sign Top quark pairs at the LHCNov 05 2003Nov 06 2003We study the possibility of same sign top quark pair production at the LHC (and the VLHC) as a direct probe of FCNC processes. Besides the SM neutral Z boson, two other neutral bosons are considered, a top-Higgs type scalar and a Z' boson that appear ... More
Quantum Monte Carlo simulations of the half-filled two-dimensional Kondo lattice modelApr 13 1999The 2D half-filled Kondo lattice model with exchange J and nearest neighbor hopping t is considered. It is shown that this model belongs to a class of Hamiltonians for which zero-temperature auxiliary field Monte Carlo methods may be efficiently applied. ... More
A Self-Organizing Neural Scheme for Door Detection in Different EnvironmentsJan 03 2013Doors are important landmarks for indoor mobile robot navigation and also assist blind people to independently access unfamiliar buildings. Most existing algorithms of door detection are limited to work for familiar environments because of restricted ... More
Geodesics on an ellipsoid of revolutionFeb 07 2011Algorithms for the computation of the forward and inverse geodesic problems for an ellipsoid of revolution are derived. These are accurate to better than 15 nm when applied to the terrestrial ellipsoids. The solutions of other problems involving geodesics ... More
Stochastic Ion Heating by a Lower Hybrid Wave: IIJan 07 2005The motion of an ion in a coherent lower hybrid wave (characterized by |k_parallel| << |k_perp| and omega >> Omega_i) in a tokamak plasma is studied. For ions satisfying v_perp > omega/k_perp, the Lorentz force law for the ions is reduced to a set of ... More
Right-left asymmetry of radiation from fission induced by polarised neutronsFeb 09 2009The effect of the right-left asymmetry is considered in the angular distribution of gamma quanta from fission of U-235 by polarised thermal neutrons, which depends on the polarisation of the neutrons with respect to the gamma-fission plane. Electric dipole ... More
Angula distanco en kalotoDec 02 2003A cap in a 2-D sphere is considered, smaller than an hemisphere. Two points are randomly chosen in the cap. The probability density that the angular separation between the points have a given value is obtained. The knowledge of this function is important ... More
Movoj sub newtona logaritma potencialoOct 16 2003A linear density of mass is assumed uniformly distributed along an infinitely long straight line. All possible motions of a test particle are described, under the newtonian logarithmic gravitational potential alone. Those most interesting occur in planes ... More
On the mixing time of the 2D stochastic Ising model with "plus" boundary conditions at low temperatureMay 19 2009Sep 15 2009We consider the Glauber dynamics for the 2D Ising model in a box of side L, at inverse temperature $\beta$ and random boundary conditions $\tau$ whose distribution P either stochastically dominates the extremal plus phase (hence the quotation marks in ... More
The index of isolated umbilics on surfaces of non-positive curvatureApr 09 2014It is shown that if a $C^2$ surface $M\subset\mathbb R^3$ has negative curvature on the complement of a point $q\in M$, then the $\mathbb Z/2$-valued Poincar\'e-Hopf index at $q$ of either distribution of principal directions on $M-\{q\}$ is non-positive. ... More
The Study of Nebular Emission on Nearby Spiral Galaxies in the IFU EraNov 14 2013A new generation of wide-field emission-line surveys based on integral field units (IFU) is allowing us to obtain spatially resolved information of the gas-phase emission in nearby late-type galaxies, based on large samples of HII regions and full two-dimensional ... More
A hyperbolic version of the phasor addition formulaNov 20 2014In this article we review the basics of the phasor formalism in a rigorous way, highlighting the physical motivation behind it and presenting a hyperbolic counterpart of the phasor addition formula.
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
Surface induced disorder in body-centered cubic alloysFeb 10 2000We present Monte Carlo simulations of surface induced disordering in a model of a binary alloy on a bcc lattice which undergoes a first order bulk transition from the ordered DO3 phase to the disordered A2 phase. The data are analyzed in terms of an effective ... More
Instance Space of the Number Partitioning ProblemNov 01 1999Within the replica framework we study analytically the instance space of the number partitioning problem. This classic integer programming problem consists of partitioning a sequence of N positive real numbers $\{a_1, a_2,..., a_N}$ (the instance) into ... More
Fokker-Planck and Quasilinear CodesJan 13 2005The interaction of radio-frequency waves with a plasma is described by a Fokker-Planck equation with an added quasilinear term. Methods for solving this equation on a computer are discussed.
Numerical Techniques for the Study of Long-Time CorrelationsJan 26 2004In the study of long-time correlations extremely long orbits must be calculated. This may be accomplished much more reliably using fixed-point arithmetic. Use of this arithmetic on the Cray-1 computer is illustrated.
Phase diagram of the half-filled two-dimensional SU(N) Hubbard-Heisenberg model: a quantum Monte Carlo studyJun 03 2004We investigate the phase diagram of the half-filled SU(N) Hubbard-Heisenberg model with hopping t, exchange J and Hubbard U, on a square lattice. In the large-N limit, and as a function of decreasing values of t/J, the model shows a transition from a ... More
Coherence scale of the two-dimensional Kondo Lattice modelJan 07 2004A doped hole in the two-dimensional half-filled Kondo lattice model with exchange J and hopping t has momentum (pi,pi) irrespective of the coupling J/t. The quasiparticle residue of the doped hole, Z_{(\pi, \pi)}, tracks the Kondo scale, T_K, of the corresponding ... More
UHECRs from the Radio Lobes of AGNsSep 23 2008Oct 07 2008We report a stochastic mechanism of particle acceleration from first principles in an environment having properties like those of Radio Lobes in AGNs. We show that energies $\sim 10^{20}$ eV are reached in $\sim 10^6$ years for protons. Our results reopen ... More
Taub, Rindler, and the static plateFeb 03 2005An infinite 3D plate of homogeneous incompressible fluid is considered, with finite thickness, together with a 2D infinite homogeneous mass in its centre. Einstein equations are exactly solved, in the interior of the 3D mass. The solution is joined to ... More
Separations inside a cubeDec 28 2001Two points are randomly selected inside a three-dimensional euclidian cube. The value l of their separation lies somewhere between zero and the length of a diagonal of the cube. The probability density P(l) of the separation is obtained analytically. ... More
Cosmic crystallography in a circleMay 15 2000Oct 05 2000In a circle (an S^1) with circumference 1 assume m objects distributed pseudo-randomly. In the universal covering R^1 assume the objects replicated accordingly, and take an interval L>1. In this interval, make the normalized histogram of the pair separations ... More
Synchronization of non-chaotic dynamical systemsAug 09 1999Dec 14 2000A synchronization mechanism driven by annealed noise is studied for two replicas of a coupled-map lattice which exhibits stable chaos (SC), i.e. irregular behavior despite a negative Lyapunov spectrum. We show that the observed synchronization transition, ... More
tbW vertex in the Littlest Higgs Model with T-parityOct 27 2008Feb 12 2009A study of the effective tbW vertex is done in the littlest Higgs model with T parity that includes the one loop induced weak dipole coefficient f_{2R}. The top's width, the W-boson helicity in the t-> bW^+ decay as well as the t-channel and the s-channel ... More
Non-Statistical gamma Rays from FragmentsOct 09 2007Polarization mechanism by Strutinsky-Denisov gives rise to the electric dipole radiation from fragments. Its probability calculated within the LDM turns out to be ~3.5x10-2 per fission. The radiation occurs during thermolization of the post-rupture deformation ... More
Stochastic Optimal Control with Delay in the Control II: Verification Theorem and Optimal FeedbacksJul 21 2016We consider a stochastic optimal control problem governed by a stochastic differential equation with delay in the control. Using a result of existence and uniqueness of a sufficiently regular mild solution of the associated Hamilton-Jacobi-Bellman (HJB) ... More
Measurement of wave-particle interaction and metastable lifetime using laser-induced fluorescenceFeb 27 2019Extensive information, such as ion temperature and wave-particle interactions, can be obtained by direct measurement of ion distribution functions using laser-induced fluorescence (LIF). This nonintrusive plasma diagnostic provides an important window ... More
Notes on the Third Law of Thermodynamics.IOct 08 2002We analyze some aspects of the third law of thermodynamics. We first review both the entropic version (N) and the unattainability version (U) and the relation occurring between them. Then, we heuristically interpret (N) as a continuity boundary condition ... More
Notes on Quasi-Homogeneous Functions in ThermodynamicsOct 07 2002A special kind of quasi-homogeneity occurring in thermodynamic potentials of standard thermodynamics is pointed out. Some formal consequences are also discussed.
nuMSM--Predictions for Neutrinoless Double Beta DecayMay 30 2005We give the prediction on the effective Majorana mass for neutrinoless double $\beta$ decay in a simple extension of the Standard Model (nuMSM). The model adds three right-handed neutrinos with masses smaller than the electroweak scale, and explains dark ... More
Use of singular classical solutions for calculation of multiparticle cross sections in field theoryJan 11 1999A method of reducing the problem of the calculation of tree multiparticle cross sections in $\phi^4$ theory to the solution of a singular classical Euclidean boundary value problem is introduced. The solutions are obtained numerically in terms of the ... More
The Static Potential in the SU(2) Higgs ModelOct 28 1999The static potential in the confinement ``phase'' of the SU(2) Higgs model is studied. In particular, the observation of the screening (called string breaking) of the static quarks by the dynamical light quarks leading to the formation of two static-light ... More
String breaking and lines of constant physics in the SU(2) Higgs modelSep 29 1999We present results for the ground state and first excited state static potentials in the confinement "phase" of the SU(2) Higgs model. String breaking and the crossing of the energy levels are clearly visible. We address the question of the cut-off effects ... More
Electroweak phase transition: recent resultsOct 15 1999Recent results of four-dimensional (4d) lattice simulations on the finite temperature electroweak phase transition (EWPT) are discussed. The phase transition is of first order in the SU(2)-Higgs model below the end point Higgs mass 66.5$\pm$1.4 GeV. For ... More
Three dimensional large N monopole gasOct 17 1996Mar 28 1997We study the large N limit in the presence of magnetic monopoles in the Yang-Mills/Higgs model in three dimensions. The physics in the limit depends strongly on the distribution of eigenvalues of the Higgs field in the vacuum, and we propose a particular, ... More
Fermion Masses at intermediate Tan(beta): Unification of Yukawa DeterminantsOct 24 2006In the context of the Grand Unified MSSM, we investigate the fermion mass matrices at GUT scale. We note that from the experimental mass pattern the determinants of the Yukawa matrices at this scale can be unified with good precision. Taking the unification ... More
On decaying rate of a quantum stateJul 20 2005Decaying rate of a quantum system investigated using the Fubini-Study definition of distance between states.
The quest for low-energy supersymmetry and the role of high-energy $e^+e^-$ collidersMar 09 1992The motivations for low-energy supersymmetry and the main features of the minimal supersymmetric extension of the Standard Model are reviewed. Possible non-minimal models and the issue of gauge coupling unification are also discussed. Theoretical results ... More
Theory and Data Analysis for the High Momentum End of $^4$He spectrumDec 15 1998The hybridization of the single-excitation branch with the two-excitation continuum is reconsidered from the theoretical point of view by including the effect of the interference term between one and two excitations. The phenomenological theory presented ... More
The Effective Fine Structure Constant at TESLA EnergiesMay 27 2001We present a new estimate of the hadronic contribution to the shift in the fine structure constant at LEP and TESLA energies and calculate the effective fine structure constant. Substantial progress in a precise determination of this important parameter ... More
The running fine structure constant alpha(E) via the Adler functionJul 26 2008We present an up-to-date analysis for a precise determination of the effective fine structure constant and discuss the prospects for future improvements. We advocate to use a determination monitored by the Adler function which allows us to exploit perturbative ... More
Hadronic Contributions to the Photon Vacuum Polarization and their Role in Precision PhysicsApr 30 2001Dec 09 2002I review recent evaluations of the hadronic contribution to the shift in the fine structure constant and to the anomalous magnetic moment of the muon. Substantial progress in a precise determination of these important observables is a consequence of substantially ... More
Facts of life with gamma(5)May 26 2000The increasing precision of many experiments in elementary particle physics leads to continuing interest in perturbative higher order calculations in the electroweak Standard Model or extensions of it. Such calculations are of increasing complexity because ... More
Hadronic effects in (g-2)_mu and alpha_QED (M_Z): Status and perspectivesJan 22 1999I review recent evaluations of the hadronic contributions to the muon anomalous magnetic moment (g-2)_mu and to the effective fine structure constant alpha (M_Z). A new estimate for the hadronic shift delta_alpha hadronic = 0.027782 +/- 0.000254 is presented ... More
A simple model of energy expenditure in human locomotionSep 06 2006A simple harmonic oscillator model is proposed to describe the mechanical power involved in human locomotion. In this framework, by taking into account the anthropometric parameters of a standard individual, we are able to calculate the speed-power curves ... More
Generalised relativistic Ohm's laws, extended gauge transformations and magnetic linkingNov 06 2015Generalisations of the relativistic ideal Ohm's law are presented that include specific dynamical features of the current carrying particles in a plasma. Cases of interest for space and laboratory plasmas are identified where these generalisations allow ... More