Results for "J. Laverock"

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The electronic structure of {\em R}NiC$_2$ intermetallic compoundsMar 10 2009Aug 18 2009First-principles calculations of the electronic structure of members of the $R$NiC$_2$ series are presented, and their Fermi surfaces investigated for nesting propensities which might be linked to the charge-density waves exhibited by certain members ... More
Vacancy defect positron lifetimes in strontium titanateOct 23 2008The results of positron annihilation lifetime spectroscopy measurements on undoped, electron irradiated, and Nb doped SrTiO3 single crystals are reported. Perfect lattice and vacancy defect positron lifetimes were calculated using two different first-principles ... More
Maximum entropy deconvolution of resonant inelastic x-ray scattering spectraJul 20 2011Feb 10 2012Resonant inelastic x-ray scattering (RIXS) has become a powerful tool in the study of the electronic structure of condensed matter. Although the linewidths of many RIXS features are narrow, the experimental broadening can often hamper the identification ... More
Experimental determination of the state-dependent enhancement of the electron-positron momentum density in solidsMay 26 2010Oct 13 2010The state-dependence of the enhancement of the electron-positron momentum density is investigated for some transition and simple metals (Cr, V, Ag and Al). Quantitative comparison with linearized muffin-tin orbital calculations of the corresponding quantity ... More
Fermi surface of an important nano-sized metastable phase: Al$_3$LiSep 12 2010Nanoscale particles embedded in a metallic matrix are of considerable interest as a route towards identifying and tailoring material properties. We present a detailed investigation of the electronic structure, and in particular the Fermi surface, of a ... More
Enhanced electron correlations at the SrxCa1-xVO3 surfaceApr 20 2015We report hard x-ray photoemission spectroscopy measurements of the electronic structure of the prototypical correlated oxide SrxCa1-xVO3. By comparing spectra recorded at different excitation energies, we show that 2.2 keV photoelectrons contain a substantial ... More
Nano-engineering of electron correlation in oxide superlatticesMar 14 2019Oxide heterostructures and superlattices have attracted a great deal of attention in recent years owing to the rich exotic properties encountered at their interfaces. We focus on the potential of tunable correlated oxides by investigating the spectral ... More
De Haas-van Alphen oscillations in the charge-density wave compound lanthanum tritelluride (LaTe_3)May 06 2008De Haas-van Alphen oscillations were measured in lanthanum tritelluride (LaTe_3) to probe the partially gapped Fermi surface resulting from charge density wave (CDW) formation. Three distinct frequencies were observed, one of which can be correlated with ... More
Fermi surface nesting and charge-density wave formation in rare-earth tritelluridesJan 05 2005The Fermi surface of rare-earth tri-tellurides ({\it R}Te$_{3}$) is investigated in terms of the nesting driven charge-density wave formation using positron annihilation and first-principles LMTO calculations. Fermi surface nesting is revealed as a strong ... More
Charge density wave formation in $R_{2}$Te$_{5}$ ($R$=Nd, Sm and Gd)Dec 13 2007The rare earth ($R$) tellurides $R_2$Te$_5$ have a crystal structure intermediate between that of $R$Te$_2$ and $R$Te$_3$, consisting of alternating single and double Te planes sandwiched between $R$Te block layers. We have successfully grown single crystals ... More
Bulk Spin Polarization of Co$_{(1-x)}$Fe$_x$S$_2$Nov 27 2009We report on a new method to determine the degree of bulk spin polarization in single crystal Co$_{(1-x)}$Fe$_x$S$_2$ by modeling magnetic Compton scattering with {\it ab initio} calculations. Spin-dependent Compton profiles were measured for CoS$_2$ ... More
Electronic structure of the kagome staircase compounds Ni3V2O8 and Co3V2O8May 01 2013The electronic structure of the kagome staircase compounds, Ni3V2O8 and Co3V2O8, has been investigated using soft x-ray absorption, soft x-ray emission, and resonant inelastic x-ray scattering (RIXS). Comparison between the two compounds, and with first ... More
Resonant soft x-ray emission as a bulk probe of correlated electron behavior in metallic Sr$_x$Ca$_{1-x}$VO$_3$Jul 24 2013The evolution of electron correlation in Sr$_{x}$Ca$_{1-x}$VO$_3$ has been studied using a combination of bulk-sensitive resonant soft x-ray emission spectroscopy (RXES), surface-sensitive photoemission spectroscopy (PES), and ab initio band structure ... More
k-resolved susceptibility function of 2H-TaSe2 from angle-resolved photoemissionJul 19 2013The connection between the Fermi surface and charge-density wave (CDW) order is revisited in 2H-TaSe2. Using angle-resolved photoemission spectroscopy, ab initio band structure calculations, and an accurate tight-binding model, we develop the empirical ... More
Observation of weakened V-V dimers in the monoclinic metallic phase of strained VO2Mar 13 2019Emergent order at mesoscopic length scales in condensed matter can provide fundamental insight into the underlying competing interactions and their relationship with the order parameter. Using spectromicroscopy, we show that mesoscopic stripe order near ... More
Observation of a strongly nested Fermi surface in the shape-memory alloy Ni[0.62]Al[0.38]Feb 01 2006The Fermi surface topology of the shape-memory alloy Ni[0.62]Al[0.38] has been determined using Compton scattering. A large area of this Fermi surface can be made to nest with other areas by translation through a vector of ~ 0.18 [1,1,0] (2pi/a), which ... More
Direct Observation of Decoupled Structural and Electronic Transitions and an Ambient Pressure Monoclinic-Like Metallic Phase of VO$_2$Nov 17 2014We report the simultaneous measurement of the structural and electronic components of the metal-insulator transition of VO$_2$ using electron and photoelectron spectroscopies and microscopies. We show that these evolve over different temperature scales, ... More
Effect of Chemical Pressure on the Charge Density Wave Transition in Rare-earth Tritellurides RTe_3Oct 11 2006Oct 09 2007The charge density wave transition is investigated in the bi-layer family of rare earth tritelluride RTe_3 compounds (R = Sm, Gd, Tb, Dy, Ho, Er, Tm) via high resolution x-ray diffraction and electrical resistivity. The transition temperature increases ... More
Photoemission evidence for crossover from Peierls-like to Mott-like transition in highly strained VO$_2$Nov 16 2012We present a spectroscopic study that reveals that the metal-insulator transition of strained VO$_2$ thin films may be driven towards a purely electronic transition, which does not rely on the Peierls dimerization, by the application of mechanical strain. ... More
Strain dependence of bonding and hybridization across the metal-insulator transition of VO2Feb 10 2012Soft x-ray spectroscopy is used to investigate the strain dependence of the metal-insulator transition of VO2. Changes in the strength of the V 3d - O 2p hybridization are observed across the transition, and are linked to the structural distortion. Furthermore, ... More
Bulk electronic structure of optimally doped Ba(Fe$_{1-x}$Co$_{x}$)$_2$As$_2$Sep 17 2009Feb 24 2010We report high-resolution, bulk Compton scattering measurements unveiling the Fermi surface of an optimally-doped iron-arsenide superconductor, Ba(Fe$_{0.93}$Co$_{0.07}$)$_2$As$_2$. Our measurements are in agreement with first-principles calculations ... More
Elliptical hole pockets in the Fermi surfaces of unhydrated and hydrated sodium cobalt oxidesAug 23 2007The surprise discovery of superconductivity below 5K in sodium cobalt oxides when hydrated with water has caught the attention of experimentalists and theorists alike. Most explanations for its occurence have focused heavily on the properties of some ... More
Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulatorAug 16 2015Feb 18 2016The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn$_{1-x}$In$_{x}$Te), and for low indium contents ($x=0.04$) it is known that the topological surface states are preserved. Here we present ... More
Low-energy V t2g orbital excitations in NdVO3Nov 17 2014The electronic structure of NdVO3, YVO3 has been investigated as a function of sample temperature using resonant inelastic soft x-ray scattering at the V L3-edge. Most of the observed spectral features are in good agreement with an atomic crystal-field ... More
ARPES Study of the Evolution of Band Structure and Charge Density Wave Properties in RTe3 for R = Y, La, Ce, Sm, Gd, Tb and DyJan 17 2008We present a detailed ARPES investigation of the RTe3 family, which sets this system as an ideal "textbook" example for the formation of a nesting driven Charge Density Wave (CDW). This family indeed exhibits the full range of phenomena that can be associated ... More
Transport behavior and electronic structure of phase pure VO2 thin films grown on c-plane sapphire under different O2 partial pressureJul 22 2013We grew highly textured phase pure VO2 thin films on c-plane Al2O3 substrates with different oxygen partial pressure. X-ray absorption and photoemission spectroscopy confirm the identical valence state of vanadium ions despite the different oxygen pressure ... 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.
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
Virtual photon structure from jet productionJul 08 1997Some aspects of extracting the information on the structure of virtual photons from jet production in ep and e^+e^- collisions are discussed.
Virtual Photon Structure from Jet Production at HERANov 21 1996The feasibility of measuring parton distribution functions of of virtual photons via the jet production at HERA is investigated.
Numeration-automatic sequencesMay 17 2006We present a base class of automata that induce a numeration system and we give an algorithm to give the n-th word in the language of the automaton when the expansion of n in the induced numeration system is feeded to the automaton. Furthermore we give ... More
Generating conjecture and Einstein-Maxwell field of plane symmetryApr 10 2000For the plane symmetry we have found the electro-vacuum exact solutions of the Einstein-Maxwell equations and we have shown that one of them is equivalent to the McVittie solution of a charged infinite thin plane. The analytical extension has been accomplished ... More
Interaction of antiproton with nucleiFeb 19 2015We performed fully self-consistent calculations of $\bar{p}$-nuclear bound states within the relativistic mean-field (RMF) model. The G-parity motivated $\bar{p}$-meson coupling constants were adjusted to yield potentials consistent with $\bar{p}$-atom ... More
2 and 3-point functions in the ENJL-modelSep 06 1994We discuss the extended Nambu-Jona-Lasinio model as a low energy expansion, all two-point functions and an example of a three-point function to all orders in momenta and quark masses. The model is treated at leading level in $1/N_c$ but otherwise exact. ... More
Quantum Space-time and Classical GravityJul 24 1996A method has been recently proposed for defining an arbitrary number of differential calculi over a given noncommutative associative algebra. As an example a version of quantized space-time is considered here. It is found that there is a natural differential ... More
Spin diffusion of the t-J modelDec 12 1994Dec 13 1994The spin-diffusion constant of the 2D $t-J$ model is calculated for the first time using an analytical approach at high temperatures and a recently-developed numerical method based on the Lanczos technique combined with random sampling in the intermediate ... More
Computational Ergodicity of $s^4$Nov 07 1994It is known that there are four-manifolds which are not algorithmically recognizable. This implies that there exist triangulations of these manifolds which are separated by large barriers from the point of view of the computer algorithm. We have not observed ... More
On the exponential bound in four dimensional simplicial gravityMay 11 1994Simplicial quantum gravity has been proposed as a regularization for four dimensional quantum gravity. The partition function is constructed by performing a weighted sum over all triangulations of the 4-sphere. The model is well-defined only if the number ... More
Distance growth of quantum states due to initial system--environment correlationsMay 03 2010Intriguing features of the distance between two arbitrary states of an open quantum system are identified that are induced by initial system-environment correlations. As an example, we analyze a qubit dephasingly coupled to a bosonic environment. Within ... More
Effective fermion kinematics from a modified quantum gravityJun 11 2015Sep 05 2016We consider a classical fermion and a classical scalar, propagating on two different kinds of 4-dimensional diffeomorphism breaking gravity backgrounds, and we derive the one-loop effective dispersion relation for matter, after integrating out gravitons. ... More
Negative Screenings in Conformal Field Theory and 2D Gravity: The Braiding MatrixApr 20 1999We consider an extension of the Coulomb gas picture which is motivated by Liouville theory and contains negative powers of screening operators on the same footing as positive ones. The braiding problem for chiral vertex operators in this extended framework ... More
High-Order Coupled Cluster Method (CCM) Formalism 2 -- "Generalised" Expectation Values: Spin-Spin Correlation Functions for Frustrated and Unfrustrated 2D AntiferromagnetsNov 27 2009Recent 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. In this article, we describe how "generalised" expectation values for a wide range of one- and two-body ... More
Solution of the Skyrme-Hartree-Fock equations in the Cartesian deformed harmonic oscillator basis. (I) The methodNov 17 1996We describe a method of solving the nuclear Skyrme-Hartree-Fock problem by using a deformed Cartesian harmonic oscillator basis. The complete list of expressions required to calculate local densities, total energy, and self-consistent fields is presented, ... More
A term-rewriting system for computer quantum algebraSep 25 2008Existing computer algebra packages do not fully support quantum mechanics calculations in Dirac's notation. I present the foundation for building such support: a mathematical system for the symbolic manipulation of expressions used in the invariant formalism ... More
Impact of LISA's low frequency sensitivity on observations of massive black hole mergersNov 22 2004LISA will be able to detect gravitational waves from inspiralling massive black hole (MBH) binaries out to redshifts z > 10. If the binary masses and luminosity distances can be extracted from the LISA data stream, this information can be used to reveal ... More
Jitter Self-Compton Process: GeV Emission of GRB 100728AMar 02 2012Jitter radiation, the emission of relativistic electrons in a random and small-scale magnetic field, has been applied to explain the gamma-ray burst (GRB) prompt emission. The seed photons produced from jitter radiation can be scattered by thermal/nonthermal ... More
Symmetry and Stability of Homogenuous Flocks. A Position PaperOct 24 2018The study of the movement of flocks, whether biological or technological is motivated by the desire to understand the capability of coherent motion of a large number of agents that only receive very limited information. In a biological flock a large group ... More
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
Transport properties of electrons and holes in a CuO2 layer doped by field effectMar 06 2002Apr 17 2002We propose a model for explaining the recent results obtained by J. Schon et al (1,2) on transport properties of electrons and holes in one plane of CuO2 in a layered cuprate (CaCuO2) where the carriers are created using a field effect transistor (FET). ... More