Results for "J. Derouillat"

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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
Stability of spherical stellar systems I : Analytical resultsNov 22 1995The so-called ``symplectic method'' is used for studying the linear stability of a self-gravitating collisionless stellar system, in which the particles are also submitted to an external potential. The system is steady and spherically symmetric, and its ... More
Center Disorder in the 3D Georgi-Glashow ModelApr 15 1998We present a number of arguments relating magnetic disorder to center disorder, in pure Yang-Mills theory in D=3 and D=4 dimensions. In the case of the D=3 Georgi-Glashow model, we point out that the abelian field distribution is not adequatedly represented, ... More
The Impact of Galaxy Formation on the Diffuse Background RadiationOct 23 2000The far infrared background is a sink for the hidden aspects of galaxy formation. At optical wavelengths, ellipticals and spheroids are old, even at $z \sim 1.$ Neither the luminous formation phase nor their early evolution is seen in the visible. We ... More
Recoil Polarization for Delta Excitation in Pion ElectroproductionMay 23 2005We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W=1.23 GeV at Q^2=1.0 (GeV/c)^2, obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed ... More
Spinons and helimagnons in the frustrated Heisenberg chainFeb 23 2012We investigate the dynamical spin structure factor S(q,w) for the Heisenberg chain with ferromagnetic nearest (J1<0) and antiferromagnetic next-nearest (J2>0) neighbor exchange using bosonization and a time-dependent density-matrix renormalization group ... More
Non-adiabatic primordial fluctuationsNov 10 2009Apr 19 2010We consider general mixtures of isocurvature and adiabatic cosmological perturbations. With a minimal assumption set consisting of the linearized Einstein equations and a primordial perfect fluid we derive the second-order action and its curvature variables. ... More
Nuclear time-reversal violation and the Schiff moment of 225RaMar 22 2005May 12 2005We present a comprehensive mean-field calculation of the Schiff moment of the nucleus 225Ra, the quantity which determines the static electric dipole moment of the corresponding atom if time-reversal (T) invariance is violated in the nucleus. The calculation ... More
Solution of the Skyrme-Hartree-Fock equations in the Cartesian deformed harmonic-oscillator basis. (III) HFODD (v1.75r): a new version of the programMar 01 2000We describe the new version (v1.75r) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock problem by using the Cartesian deformed harmonic-oscillator basis. Three minor errors that went undetected in the previous version have been corrected. ... More
On Zero-Mass Ground States in Super-Membrane Matrix ModelsJan 23 1997We recall a formulation of super-membrane theory in terms of certain matrix models. These models are known to have a mass spectrum given by the positive half-axis. We show that, for the simplest such matrix model, a normalizable zero-mass ground state ... More
Measurement of CP violation at a Neutrino FactoryMay 29 2001The prospects of measuring CP violation in the leptonic sector using the intense neutrino beams arising from muon decay in the straight sections of a muon accumulator ring (the so-called neutrino factory) are discussed.
Thermalization of Quantum Fields from Time-Reversal Invariant Evolution EquationsJun 14 2000We study the time evolution of correlation functions in closed quantum systems for nonequilibrium ensembles of initial conditions. For a scalar quantum field theory we show that generic time-reversal invariant evolutions approach equilibrium at large ... More
Permutation Group Symmetry and CorrelationsJun 11 2013Correlation factors are constructed that are consistent with the permutation symmetry group of N Fermions at given value of the filling factor.
Horizontal symmetry in the algebraic approach of genetic codeFeb 14 2013Using concepts of physics of elementary particles concerning the breaking of symmetry and grannd unified theory we propose to study with the algebraic approximation the degeneracy finded in the genetic code with the incorporation of a horizontal symmetry ... More
The winds of the hot massive first starsSep 07 2005We study dynamical aspects of circumstellar environment around massive zero-metallicity first stars. For this purpose we apply our NLTE wind models. We show that the hydrogen-helium stellar wind from stationary massive first generation (Population III) ... More
Inverted crossover resonance aiding laser cooling of $^{171}$YbMar 03 2016Apr 19 2016We observe an inverted crossover resonance in $\pi$-driven four-level systems, where $F'-F=0,+1$. The signal is observed through saturated absorption spectroscopy of the $(6s^{2})$ $^{1}S_{0}$ $-$ $(6s6p)$ $^{3}P_{1}$ transition in $^{171}$Yb, where the ... More
Hartree shift in unitary Fermi gasesMar 24 2011The Hartree energy shift is calculated for a unitary Fermi gas. By including the momentum dependence of the scattering amplitude explicitly, the Hartree energy shift remains finite even at unitarity. Extending the theory also for spin-imbalanced systems ... More
Coulomb blockade in electron transport through a C$_{60}$ molecule from first principlesMay 23 2005We present results of spin-unrestricted first-principles quantum transport for a gated C$_{60}$ molecule weakly contacted to Al electrodes, making emphasis on the role played by the electronic localization and the spin degree of freedom. As expected, ... More
Nuclear suppression of dileptons at forward rapiditiesDec 14 2010Data from E772 and E866 experiments on the Drell-Yan process exhibit a significant nuclear suppression at large Feynman xF. We show that a corresponding kinematic region does not allow to interpret this as a manifestation of coherence or a Color Glass ... More
Asymmetric Wolf-Rayet winds: implications for GRB afterglowsJan 25 2007Recent observations of Wolf-Rayet (WR) binaries WR151 and WR155 infer that their stellar winds are asymmetric. We show that such asymmetries can alter the stellar-wind bubble structure, bringing the wind-termination shock closer to the WR star. If the ... More
Unbiased estimators in Quantum Monte Carlo methods: application to liquid $^4$HeJan 18 1995A Monte Carlo algorithm for computing quantum mechanical expectation values of coordinate operators in many body problems is presented. The algorithm, that relies on the forward walking method, fits naturally in a Green's Function Monte Carlo calculation, ... More
Asymptotic cones and Assouad-Nagata dimensionOct 10 2006Oct 20 2006We prove the dimension of any asymptotic cone over a metric space X does not exceed the asymptotic Assouad-Nagata dimension of X. This improves a result of Dranishnikov and Smith who showed that dim(Y) does not exceed asymptotic Assouad-Nagata dimension ... More
A Plasma Instability Theory of Gamma-Ray Burst EmissionApr 02 1999A new theory for gamma-ray burst radiation is presented. In this theory, magnetic fields and relativistic electrons are created through plasma processes arising as a relativistic shell passes through the interstellar medium. The gamma-rays are produced ... More
Pi^0_1 ordinal analysis beyond first order arithmeticDec 11 2012In this paper we give an overview of an essential part of a Pi^0_1 ordinal analysis of Peano Arithmetic (PA) as presented by Beklemishev. This analysis is mainly performed within the polymodal provability logic GLP. We reflect on ways of extending this ... More
Fazendo 3D com uma camera soDec 14 2010Jan 29 2012A simple system to make stereo photography or videos based in just two mirrors was made in 1989 and recently adapted to a digital camera setup.
Enlarging Holograms Under White Light, a Way to Save Holographic MaterialMay 08 2009We developed techniques for employing holographic screens under white light, first exhibited to the public in 1989 (3) (4) which demonstrated the possibility of enlarging holograms already in 1990 (5). Fig. 1 shows how we encode views in a first step. ... More
White Light Colour Photography for Rendering Holoimages in a Diffractive ScreenApr 16 2009The capability of color encoding the continuous sequence of views from a scene was demonstrated previously by the author (1990). In the present work, the scheme for this process is shown where white light from a black and white object is diffracted at ... More
On the quality of the Olmec mirrors and its utilizationJan 29 2007Archaeological mirrors from the Olmec civilization were analyzed in the context of bibliography produced in the last two decades. Photographs of its images are showed as a proof of its good quality. Some suggestions are made on its probable utilization. ... More
Lagrangian and Hamiltonian for the Bondi-Sachs metricsMar 31 2004Feb 03 2015We calculate the Hilbert action for the Bondi-Sachs metrics. It yields the Einstein vacuum equations in a closed form. Following the Dirac approach to constrained systems we investigate the related Hamiltonian formulation.
Quartz Tuning Forks and Acoustic Phenomena - Application to Superfluid HeliumApr 09 2013Jan 30 2016Immersed mechanical resonators are well suited for probing the properties of fluids, since the surrounding environment influences the resonant characteristics of such oscillators in several ways. Quartz tuning forks have gained much popularity in recent ... More
Infrared dynamic polarizability of HD+ rovibrational statesJun 07 2011A calculation of dynamic polarizabilities of rovibrational states with vibrational quantum number $v=0-7$ and rotational quantum number $J=0,1$ in the 1s$\sigma_g$ ground-state potential of HD$^+$ is presented. Polarizability contributions by transitions ... More
Curvettes and clusters of infinitely near pointsMar 30 2009Jul 03 2011The aim of this paper is to revise the theory of clusters of infinitely near points for arbitrary fields. We describe in particular the intersection matrix of such a cluster, we introduce the notion of curvette over an arbitrary field and we relate it ... More
Phase transitions in systems of magnetic dipoles on a square lattice with quenched disorderSep 14 2008We study by Monte Carlo simulations the effect of quenched orientational disorder in systems of interacting classical dipoles on a square lattice. Each dipole can lie along any of two perpendicular axes that form an angle psi with the principal axes of ... More
Effective realization of random magnetic fields in compounds with large single-ion anisotropyJun 20 2016We show that spin $S=1$ system with large and random single-ion anisotropy can be at low energies mapped to a $S=1/2$ system with random magnetic fields. This is for example realized in Ni(Cl$_{1-x}$Br$_{x}$)$_2$-4SC(NH$_2$)$_2$ compound (DTNX) and therefore ... More
Building a linguistic corpus from bee dance dataJun 28 2004This paper discusses the problems and possibility of collecting bee dance data in a linguistic \textit{corpus} and use linguistic instruments such as Zipf's law and entropy statistics to decide on the question whether the dance carries information of ... More
Application of Jitter Radiation: Gamma-ray Burst Prompt PolarizationSep 20 2013A high-degree of polarization of gamma-ray burst (GRB) prompt emission has been confirmed in recent years. In this paper, we apply jitter radiation to study the polarization feature of GRB prompt emission. In our framework, relativistic electrons are ... More
An addendum to `A rigidity property for the set of all characters induced by valuations'May 28 2013This corrects and amplifies some comments made in a paper by Robert Bieri and the author with the above title.
Equivalence between the Morita categories of etale Lie groupoids and of locally grouplike Hopf algebroidsMar 13 2007Any etale Lie groupoid G is completely determined by its associated convolution algebra C_c(G) equipped with the natural Hopf algebroid structure. We extend this result to the generalized morphisms between etale Lie groupoids: we show that any principal ... More
Superlogarithmic estimates on pseudoconvex domains and CR manifoldsOct 15 2004This paper is concerned with proving superlogarithmic estimates for the operator $\Box_b$ on pseudoconvex CR manifolds and using them to establish hypoellipticity of $\Box_b$ and of the $\bar{\partial}$-Neumann problem. These estimates are established ... More
A characterization of Sobolev spaces on the sphere and an extension of Stolarsky's invariance principle to arbitrary smoothnessMar 23 2012In this paper we study reproducing kernel Hilbert spaces of arbitrary smoothness on the sphere $\mathbb{S}^d \subset \mathbb{R}^{d+1}$. The reproducing kernel is given by an integral representation using the truncated power function $(\boldsymbol{x} \cdot ... More
Chaplygin's sphereSep 01 2004Chaplygin proved the integrability by quadratures of a round sphere, rolling without slipping on a horizontal plane, with center of mass at the center of the sphere, but with arbitrary moments of inertia. Although the system is integrable in every sense ... More
A remark on the structure of the Busemann representative of a polyconvex functionSep 23 2008Let W be a polyconvex function defined on the 2 x 2 real matrices. The Busemann representative f, say, of W is the largest possible convex representative of W. Writing L for the set of affine functions on R^{5} such that a(A, det A) is less than or equal ... More
A note on Positivity of the CM line bundleMay 11 2006Aug 09 2006We show that positivity of the CM line associated to a family of polarised varieties is intimately related to the stability of its members. We prove that the CM line is nef on any curve which meets the stable locus, and that it is pseudoeffective (i.e. ... More
Social Balance and the Bernoulli EquationJan 14 2017Dec 13 2017Since the 1940's there has been an interest in the question why social networks often give rise to two antagonistic factions. Recently a dynamical model of how and why such a balance might occur was developed. This note provides an introduction to the ... More
Origin of the quasi-universality of the graphene minimal conductivityApr 15 2010Sep 16 2010It is a fact that the minimal conductivity $\sigma_0$ of most graphene samples is larger than the well-established universal value for ideal graphene $4e^2/\pi h$; in particular, larger by a factor $\gtrsim\pi$. Despite intense theoretical activity, this ... More
Vortex matter in superconducting mesoscopic disks: Structure, magnetization, and phase transitionsJun 04 1998The dense vortex matter structure and associated magnetization are calculated for type-II superconducting mesoscopic disks. The magnetization exhibits generically first-order phase transitions as the number of vortices changes by one and presents two ... More
The Cosmological Signatures and Flux Distribution of Gamma-Ray Bursts with a Broad Luminosity DistributionJul 10 1997Aug 16 1997The cosmological expansion cannot produce the reported correlations of the gamma-ray burst timescale and spectral energy with peak flux if the burst model reproduces the BATSE 3B peak-flux distribution for a non-evolving burst source density. Power law ... More
A Quantum Monte Carlo Study of Static Properties of One 3He Atom in Superfluid 4HeJul 20 1998The local environment and the energetic properties of one $^3$He atom solved in bulk superfluid $^4$He are studied by means of the diffusion Monte Carlo method. The chemical potential of the $^3$He impurity is calculated with a generalized reweighting ... More
Nuclear Suppression of Dileptons at Large xFSep 23 2009Oct 09 2009We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, ... More
A New Method for Finding Clusters of Galaxies at z>1Aug 16 1994At large redshifts, a cluster or group may be too distant for the galaxies within the cluster to be detected individually. However, the light from these ``undetected'' galaxies still modulates the surface brightness of the background sky. Clusters can ... More
Hadronization of Expanding QGPNov 04 2005We discuss how the dynamics of an exploding hot fireball of quark--gluon matter impacts the actual phase transition conditions between the deconfined and confined state of matter. We survey the chemical conditions prevailing at hadronization.
QCD Equations of State and the QGP Liquid ModelJan 15 2003Recent advances in the study of equations of state of thermal lattice Quantum Chromodynamics obtained at non-zero baryon density allow validation of the quark-gluon plasma (QGP) liquid model equations of state (EoS). We study here the properties of the ... More
Lensless Slide Projection: A Demonstrative ExperienceJun 27 2006A 2D transparency may be projected on a diffractive screen by just illuminating it with a filament lamp of the same height. Sharpness of the filament width is naturally related to sharpness on the image, but some peculiar properties makes this experience ... More
Holoprojection of Images by a Double Diffraction ProcessAug 17 2005Three dimensional images having continuous horizontal parallax were developed by wavelength enconding of view followed by a natural decoding process of projection onto a diffractive screen. It allows for the direct criation of "holoimages" by using projected ... More
Effective bounds for Faltings's delta functionDec 09 2013We obtain bounds for the Faltings's delta function for any Riemann surface of genus greater than one. The bounds are in terms of the genus of the surface and two basic quantities coming from hyperbolic geometry: The length of the shortest closed geodesic, ... More
Parametric resonance in quantum field theoryAug 07 2002Jul 09 2003We present the first study of parametric resonance in quantum field theory from a complete next-to-leading order calculation in a 1/N-expansion of the 2PI effective action, which includes scattering and memory effects. We present a complete numerical ... More
Transport Simulations with Pi and Delta In-Medium PropertiesJul 23 1998Transport simulations including in-medium properties derived in a microscopic pi + nucleon-hole + delta-hole model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial delta decay widths, pion absorption cross sections ... More
Treatment of Pionic Modes at the Nuclear Surface for Transport DescriptionsAug 22 1995Dispersion relations and amplitudes of collective pionic modes are derived in a pi + nucleon-hole + delta-hole model for use in transport descriptions by means of a local density approximation. It is discussed how pionic modes can be converted to real ... More
The Spectrum of the MSSM with Non-Standard Supersymmetry BreakingAug 24 2001Aug 29 2001The Minimal Supersymmetric Standard Model (MSSM) can include two soft breaking terms which are often neglected: a non-analytic scalar trilinear coupling and a Higgsino bilinear term. A set of high-scale boundary conditions consistent with the reparameterisation ... More
Tables of the partition functions for iron, Fe I -- Fe XApr 23 2002We present extensive tables of the Atomic Partition Function for iron ions, Fe I -- Fe X, and discuss details of the computational method. Partition functions are given in wide range of temperatures, 10^3 K < T < 10^6 K, and lowering of ionization energy ... More
Antibaryon-nucleus bound statesNov 27 2014We calculated antibaryon ($\bar{B}$ = $\bar{p}$, $\bar{\Lambda}$, $\bar{\Sigma}$, $\bar{\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{B}$-meson coupling constants were scaled to yield ... More
On Electro-weak mixing derived from radiative corrections and the necessity of the Higgs mechanismJun 12 1996Jun 20 1996Starting from the unmixed Lagrangian, the electro-weak radiative corrections are recomputed using symmetrical generalised functions. All gauge bosons acquire an indeterminate mass. Electro-weak mixing is obtained by diagonalization of the mass matrix. ... More
Quantum-Electrodynamics without renormalization V. Bosonic contributions to the photon massMay 11 1994The bosonic contributions to the photon mass are shown to be of the same form as the fermionic contributions, but of opposite sign. A mass sum rule for bosons and fermions follows from gauge invariance. Assuming completeness of the standard model the ... More
Horizons in de-Sitter SupergravityJan 14 2010Nov 26 2010We classify all pseudo-supersymmetric extremal near-horizon geometries in minimal five-dimensional de-Sitter supergravity. It is shown that the only such near-horizon geometry is the near-horizon geometry of the de-Sitter BMPV solution, and hence there ... More
A logic-based approach to data integrationOct 16 2001An important aspect of data integration involves answering queries using various resources rather than by accessing database relations. The process of transforming a query from the database relations to the resources is often referred to as query folding ... More
Graphene wormholes: A condensed matter illustration of Dirac fermions in curved spaceSep 16 2009We study the properties of graphene wormholes in which a short nanotube acts as a bridge between two graphene sheets, where the honeycomb carbon lattice is curved from the presence of 12 heptagonal defects. By taking the nanotube bridge with very small ... More
Subdirect products of finitely presented metabelian groupsJun 13 2011Jul 15 2011There has been substantial investigation in recent years of subdirect products of limit groups and their finite presentability and homological finiteness properties. To contrast the results obtained for limit groups, Baumslag, Bridson, Holt and Miller ... More
XMM-Newton Data Processing for Faint Diffuse Emission: Proton Flares, Exposure Maps and Report on EPIC MOS1 Bright CCDs ContaminationAug 04 2005We present a study of the in-flight performance of the XMM-Newton EPIC MOS and pn detectors, with focus on the influence of proton flares and vignetting on the data. The very wide range in the conditions of our sample of observations, in terms of exposure ... More
Second order Contact of Minimal SurfacesJan 18 2002The minimal surface equation $Q$ in the second order contact bundle of $R^3$, modulo translations, is provided with a complex structure and a canonical vector-valued holomorphic differential form $Omega$ on $Q\0$. The minimal surfaces $M$ in $R^3$ correspond ... More
On a Question of Glasby, Praeger, and Xia in Characteristic $2$Mar 14 2014Recently, Glasby, Praeger, and Xia asked for necessary and sufficient conditions for the `Jordan partition' $\lambda(m,n,p)$ to be standard. Previously we gave such conditions when $p$ is any odd prime. Here we give such conditions when $p=2$. Our main ... More
Generators for Decompositions of Tensor Products of Modules associated with standard Jordan partitionsAug 07 2015If $K$ is a field of finite characteristic $p$, $G$ is a cyclic group of order $q=p^\alpha$, $U$ and $W$ are indecomposable $KG$-modules with $\dim U=m$ and $\dim W=n$, and $\lambda(m,n,p)$ is a standard Jordan partition of $ m n$, we describe how to ... More
On Reasonable and Forced Goal Orderings and their Use in an Agenda-Driven Planning AlgorithmJun 01 2011The paper addresses the problem of computing goal orderings, which is one of the longstanding issues in AI planning. It makes two new contributions. First, it formally defines and discusses two different goal orderings, which are called the reasonable ... More
Multiplicative noise and charge density wave dynamics in Rb0.30MoO3Jul 17 2012We have investigated the combined effects of a multiplicative noise and nonlinear conductivity on the charge density wave (CDW) dynamics of the quasi-one dimensional conductor Rb0.30MoO3. When the amplitude of a bipolar rectangular voltage pulse excitation ... More
Broad band noise and stochastic resonance in the CDW conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002)May 09 2012We have investigated nonlinear characteristics and broad band noise in the quasi-one dimensional charge-density-wave conductors K0.30MoO3 and K0.30Mo(1-x)WxO3 (x=0.001 and x=0.002) When the amplitude of a bipolar rectangular voltage pulse excitation is ... More
Primordial fluctuations without scalar fieldsJul 10 2009Jan 29 2010We revisit the question of whether fluctuations in hydrodynamical, adiabatical matter could explain the observed structures in our Universe. We consider matter with variable equation of state $w=p_0/\ep_0$ and a concomitant (under the adiabatic assumption) ... More
Efficiency of the SQUID Ratchet Driven by External CurrentFeb 19 2015We study theoretically the efficiency of an asymmetric superconducting quantum interference device (SQUID) which is constructed as a loop with three capacitively and resistively shunted Josephson junctions. Two junctions are placed in series in one arm ... More
Solution of the Skyrme-Hartree-Fock equations in the Cartesian deformed harmonic oscillator basis. (II) The program HFODDNov 17 1996We describe the code HFODD which solves the nuclear Skyrme-Hartree-Fock problem by using the deformed Cartesian harmonic oscillator basis. The user has a possibility of choosing among various symmetries of the nuclear HF problem for rotating or non-rotating ... More
High-Order Coupled Cluster Method (CCM) Formalism 3: Finite-Size CCMFeb 23 2010Recent developments of high-order CCM have been to extend existing formalism and codes to $s \ge \frac 12$ for both the ground and excited states, and independently to "generalised" expectation values for a wide range of one- and two-body spin operators. ... More
High-Order Coupled Cluster Method (CCM) Formalism 1: Ground- and Excited-State Properties of Lattice Quantum Spin Systems with $s >= 1/2$Sep 07 2009Sep 11 2009The coupled cluster method (CCM) is a powerful and widely applied technique of modern-day quantum many-body theory. It has been used with great success in order to understand the properties of quantum magnets at zero temperature. This is due largely to ... More
An inequality between multipoint Seshadri constantsApr 10 2008Let X be a projective variety of dimension n and L be a nef divisor on X. Denote by e_d(r;X,L) the d-dimensional Seshadri constant of r very general points in X. We prove that e_d(rs;X,L) >= e_d(r;X,L)e_d(s;P^n,O_{P^n}(1)).
Outcome Modeling Using Clinical DVH DataAug 19 2015Aug 26 2015Purpose: To quantify the ability of correlation and regression analysis to extract the normal lung dose-response function from dose volume histogram (DVH) data. Methods: A local injury model is adopted, in which radiation-induced damage (functional loss) ... More
The Vapnik-Chervonenkis dimension of cubes in $\mathbb{R}^d$Dec 20 2014Nov 26 2017The Vapnik-Chervonenkis (VC) dimension of a collection of subsets of a set is an important combinatorial concept in settings such as discrete geometry and machine learning. In this paper we prove that the VC dimension of the family of $d$-dimensional ... More
Radon transformation on reductive symmetric spaces: support theoremsNov 26 2010Apr 03 2013We introduce a class of Radon transforms for reductive symmetric spaces, including the horospherical transforms, and study some of their properties. In particular we obtain a support theorem that generalizes Helgason's support theorem for the horospherical ... More
Neon Insights from Old Solar X-rays: a Plasma Temperature Dependence of the Coronal Neon ContentSep 16 2011An analysis using modern atomic data of fluxes culled from the literature for O VIII and Ne IX lines observed in solar active regions by the P78 and Solar Maximum Mission satellites confirms that the coronal Ne/O abundance ratio varies by a factor of ... More
Poissonian noise assisted transport in periodic systemsJun 11 2014We revisit the problem of transport of a harmonically driven inertial particle moving in a {\it symmetric} periodic potential, subjected to {\it unbiased} non-equilibrium generalized white Poissonian noise and coupled to thermal bath. Statistical asymmetry ... More
From constructive field theory to fractional stochastic calculus. (I) The Lévy area of fractional Brownian motion with Hurst index $α\in (1/8,1/4)$Jun 07 2010Let $B=(B_1(t),\ldots,B_d(t))$ be a $d$-dimensional fractional Brownian motion with Hurst index $\alpha<1/4$. Defining properly iterated integrals of $B$ is a difficult task because of the low H\"older regularity index of its paths. Yet rough path theory ... More
Density Matrix Renormalisation Group Calculations for Two-Dimensional Lattices: An Application to the Spin-Half and Spin-One Square-Lattice Heisenberg ModelsSep 02 2003A new density matrix renormalisation group (DMRG) approach is presented for quantum systems of two spatial dimensions. In particular, it is shown that it is possible to create a multi-chain-type 2D DMRG approach which utilises previously determined system ... More
Unstable attractors in manifoldsMay 12 2008Let $M$ be a locally compact metric space endowed with a continuous flow $\phi : M \times \mathbb{R} \longrightarrow M$. Frequently an attractor $K$ for $\phi$ exists which is of interest, not only in itself but also the dynamics in its basin of attraction ... More
Metastability and paramagnetism in superconducting mesoscopic disksAug 24 1999Dec 22 1999A projected order parameter is used to calculate, not only local minima of the Ginzburg-Landau energy functional, but also saddle points or energy barriers responsible for the metastabilities observed in superconducting mesoscopic disks (Geim et al. Nature ... More
Absence of pairing in atomic Fermi gasesMay 11 2010May 18 2010Some thoughts regarding pairing in atomic Fermi gases were considered, meant for starting discussion on the topic.
Applications harmoniques et hyperbolicité des domaines tubesOct 26 2006An application of the Zalcman renormalization theorem to harmonic functions shows that the limit functions are nonconstant affine. Extensions of this method are given for maps with values in a torus or in a complex Lie groups. As an application, we give ... More
Massive stars in their death-throesSep 07 2008Sep 11 2008The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently there are 8 detected ... More
Testing Skyrme energy-density functionals with the QRPA in low-lying vibrational states of rare-earth nucleiMay 19 2011Although nuclear energy density functionals are determined primarily by fitting to ground state properties, they are often applied in nuclear astrophysics to excited states, usually through the quasiparticle random phase approximation (QRPA). Here we ... More
Self-consistent description of multipole strength: systematic calculationsMar 26 2006We use the quasiparticle random phase approximation with a few Skyrme density functionals to calculate strength functions in the Jpi = 0+, 1-, and 2+ channels for even Ca, Ni, and Sn isotopes, from the proton drip line to the neutron drip line. We show ... More
A Plasma Instability Theory of Gamma-Ray Burst EmissionApr 02 1999A plasma instability theory is presented for the prompt radiation from gamma-ray bursts. In the theory, a highly relativistic shell interacts with the interstellar medium through the filamentation and the two-stream instabilities to convert bulk kinetic ... More
Optical linewidth of a low density Fermi-Dirac gasFeb 11 1999We study propagation of light in a Fermi-Dirac gas at zero temperature. We analytically obtain the leading density correction to the optical linewidth. This correction is a direct consequence of the quantum statistical correlations of atomic positions ... More
Three-dimensional photography by holographyMar 22 2007Color encoding of depth is shown to occur naturally in holograms that are reconstructed under white light illumination. It can be registered in a common color photograph, allowing a simple method of visual decoding by means of ordinary colored 3-D spectacles. ... More
Asymptotic step profiles from a nonlinear growth equation for vicinal surfacesMay 23 2000Aug 28 2000We study a recently proposed nonlinear evolution equation describing the collective step meander on a vicinal surface subject to the Bales-Zangwill growth instability [O. Pierre-Louis et al., Phys. Rev. Lett. (80), 4221 (1998)]. A careful numerical analysis ... More
Asymmetric particle systems on RSep 02 1999Dec 22 1999We study interacting particle systems on the real line which generalize the Hammersley process [D. Aldous and P. Diaconis, Prob. Theory Relat. Fields 103, 199-213 (1995)]. Particles jump to the right to a randomly chosen point between their previous position ... More
Improved description of charged Higgs boson production at hadron collidersSep 08 2004Jan 13 2005We present a new method for matching the two twin-processes gb->H+/-t and gg->H+/-tb in Monte Carlo event generators. The matching is done by defining a double-counting term, which is used to generate events that are subtracted from the sum of these two ... More