Results for "S. J. v. Gool"

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Sheaves and DualityApr 11 2019It has long been known in universal algebra that any distributive sublattice of congruences of an algebra which consists entirely of commuting congruences yields a sheaf representation of the algebra. In this paper we provide a generalisation of this ... More
Uniform Interpolation and Compact CongruencesApr 12 2019Uniform interpolation properties are defined for equational consequence in a variety of algebras and related to properties of compact congruences on first the free and then the finitely presented algebras of the variety. It is also shown, following related ... More
Merge decompositions, two-sided Krohn-Rhodes, and aperiodic pointlikesAug 27 2017This paper provides short proofs of two fundamental theorems of finite semigroup theory whose previous proofs were significantly longer, namely the two-sided Krohn-Rhodes decomposition theorem and Henckell's aperiodic pointlike theorem, using a new algebraic ... More
Pro-aperiodic monoids via saturated modelsSep 25 2016We apply Stone duality and model theory to study the structure theory of free pro-aperiodic monoids. Stone duality implies that elements of the free pro-aperiodic monoid may be viewed as elementary equivalence classes of pseudofinite words. Model theory ... More
Pointlike sets for varieties determined by groupsJan 15 2018For a variety of finite groups $\mathbf H$, let $\overline{\mathbf H}$ denote the variety of finite semigroups all of whose subgroups lie in $\mathbf H$. We give a characterization of the subsets of a finite semigroup that are pointlike with respect to ... More
Pro-aperiodic monoids via saturated modelsSep 25 2016Aug 28 2017We apply Stone duality and model theory to study the structure theory of free pro-aperiodic monoids. Stone duality implies that elements of the free pro-aperiodic monoid may be viewed as elementary equivalence classes of pseudofinite words. Model theory ... More
An open mapping theorem for finitely copresented Esakia spacesOct 04 2017Mar 12 2018We prove an open mapping theorem for the topological spaces dual to finitely presented Heyting algebras. This yields in particular a short, self-contained semantic proof of the uniform interpolation theorem for intuitionistic propositional logic, first ... More
Monadic second order logic as the model companion of temporal logicMay 03 2016The main focus of this paper is on bisimulation-invariant MSO, and more particularly on giving a novel model-theoretic approach to it. In model theory, a model companion of a theory is a first-order description of the class of models in which all potentially ... More
A model-theoretic characterization of monadic second order logic on infinite wordsMar 31 2015Apr 29 2016Monadic second order logic and linear temporal logic are two logical formalisms that can be used to describe classes of infinite words, i.e., first-order models based on the natural numbers with order, successor, and finitely many unary predicate symbols. ... More
Sheaf representations of MV-algebras and lattice-ordered abelian groups via dualityJun 12 2013Jun 10 2014We study representations of MV-algebras -- equivalently, unital lattice-ordered abelian groups -- through the lens of Stone-Priestley duality, using canonical extensions as an essential tool. Specifically, the theory of canonical extensions implies that ... More
Classification Driven Dynamic Image EnhancementOct 20 2017Mar 28 2018Convolutional neural networks rely on image texture and structure to serve as discriminative features to classify the image content. Image enhancement techniques can be used as preprocessing steps to help improve the overall image quality and in turn ... More
Duality and universal models for the meet-implication fragment of IPCMar 04 2014Nov 22 2014In this paper we investigate the fragment of intuitionistic logic which only uses conjunction (meet) and implication, using finite duality for distributive lattices and universal models. We give a description of the finitely generated universal models ... More
Duality and canonical extensions for stably compact spacesSep 17 2010Oct 08 2011We construct a canonical extension for strong proximity lattices in order to give an algebraic, point-free description of a finitary duality for stably compact spaces. In this setting not only morphisms, but also objects may have distinct pi- and sigma-extensions. ... More
The performance of an idealized large-area array of moderate-sized IACTsAug 20 2007We present simulations of a large array of imaging atmospheric Cherenkov telescopes (IACTs), for which the size of the array footprint is much larger than the size of the Cherenkov lightpool. To evaluate limitations of the imaging atmospheric Cherenkov ... More
Energy range of hadronic calorimeter towers and cells for high-pT jets at a 100 TeV colliderNov 04 2015Dec 28 2015This paper discusses a study of tower and cell energy ranges of a hadronic calorimeter for a 100 TeV pp collider. The dynamic energy ranges were estimated using Standard Model jets with transverse momenta above 20 TeV. The simulations were performed using ... More
Conductivity close to antiferromagnetic criticalityJul 14 2012Jan 02 2013We study the conductivity of a 3D disordered metal close to the antiferromagnetic instability within the framework of the spin-fermion model using the diagrammatic technique. We calculate the interaction correction $\delta\sigma(\omega,T)$ to the conductivity, ... More
Violations of fundamental symmetries in atoms and tests of unification theories of elementary particlesSep 12 2003High-precision measurements of violations of fundamental symmetries in atoms are a very effective means of testing the standard model of elementary particles and searching for new physics beyond it. Such studies complement measurements at high energies. ... More
The nuclear Schiff moment and time invariance violation in atomsAug 03 2001Mar 13 2002Parity and time invariance violating (P,T-odd) nuclear forces produce P,T-odd nuclear moments. In turn, these moments can induce electric dipole moments (EDMs) in atoms through the mixing of electron wavefunctions of opposite parity. The nuclear EDM is ... More
Renormalization group method for weakly coupled quantum chains: comparison with exact diagonalizationFeb 20 2004We show that numerical quasi-one-dimensional renormalization group allows accurate study of weakly coupled chains with modest computational effort. We perform a systematic comparison with exact diagonalization results in two and three-leg spin ladders ... More
Laser Excitation of Polarization Waves in a Frozen GasAug 16 1999Apr 18 2000Laser experiments with optically excited frozen gases entail the excitation of polarization waves. In a continuum approximation the waves are dispersionless, but their frequency depends on the direction of the propagation vector. An outline is given of ... More
Resonant Processes and Exciton Propagation in a Frozen GasAug 30 2000Sep 12 2000We present numerical simulations of a theory of resonant processes in a frozen gas of excited atoms interacting via dipole-dipole potentials that vary as $r^{-3}$, where $r$ is the interatomic separation. The simulations calculate time-dependent averages ... More
Isospin breaking corrections to nucleon form factors in the constituent quark modelApr 27 1995We examine isospin breaking in the nucleon wave functions due to the $u - d$ quark mass difference and the Coulomb interaction among the quarks, and their consequences on the nucleon electroweak form factors in a nonrelativistic constituent quark model. ... More
Forward Modeling of Synthetic EUV/SXR Emission from Solar Coronal Active Regions: Case of AR 11117Sep 12 2014Recent progress in obtaining high spatial resolution images of the solar corona in the extreme-ultraviolet (EUV) with Hinode, TRACE, SDO and recent Hi-C missions and soft X-ray (SXR) bands opened a new avenue in understanding the solar coronal heating, ... More
Completely reducible hypersurfaces in a pencilJan 10 2007Apr 09 2007We study completely reducible fibers of pencils of hypersurfaces on $\mathbb P^n$ and associated codimension one foliations of $\mathbb P^n$. Using methods from theory of foliations we obtain certain upper bounds for the number of these fibers as functions ... More
A Riemannian Network for SPD Matrix LearningAug 15 2016Symmetric Positive Definite (SPD) matrix learning methods have become popular in many image and video processing tasks, thanks to their ability to learn appropriate statistical representations while respecting the Riemannian geometry of the underlying ... More
Unsupervised High-level Feature Learning by Ensemble Projection for Semi-supervised Image Classification and Image ClusteringFeb 02 2016Feb 04 2016This paper investigates the problem of image classification with limited or no annotations, but abundant unlabeled data. The setting exists in many tasks such as semi-supervised image classification, image clustering, and image retrieval. Unlike previous ... More
The radiative potential method for calculations of QED radiative corrections to energy levels and electromagnetic amplitudes in many-electron atomsJul 08 2005We derive an approximate expression for a "radiative potential" which can be used to calculate QED strong Coulomb field radiative corrections to energies and electric dipole (E1) transition amplitudes in many-electron atoms with an accuracy of a few percent. ... More
Molecular Bose-Einstein condensate as an amplifier of weak interactionsJul 26 2002Collisions and chemical reactions of molecules in Bose-Einstein condensates (BECs) are extremely sensitive to weak fields. This sensitivity arises due to the high density of compound resonances and a macroscopic number of molecules with kinetic energy ... More
Resonance reactions and enhancement of weak interactions in collisions of cold moleculesMar 24 2006Aug 24 2006With the creation of ultracold atoms and molecules, a new type of chemistry - "resonance" chemistry - emerges: chemical reactions can occur when the energy of colliding atoms and molecules matches a bound state of the combined molecule (Feshbach resonance). ... More
Schwarzschild-Couder two-mirror telescope for ground-based gamma-ray astronomyAug 21 2007Schwarzschild-type aplanatic telescopes with two aspheric mirrors, configured to correct spherical and coma aberrations, are considered for application in gamma-ray astronomy utilizing the ground-based atmospheric Cherenkov technique. We use analytical ... More
Distributive envelopes and topological duality for lattices via canonical extensionsSep 12 2013We establish a topological duality for bounded lattices. The two main features of our duality are that it generalizes Stone duality for bounded distributive lattices, and that the morphisms on either side are not the standard ones. A positive consequence ... More
Does V-NIR based Image Enhancement Come with Better Features?Aug 23 2016Aug 24 2016Image enhancement using the visible (V) and near-infrared (NIR) usually enhances useful image details. The enhanced images are evaluated by observers perception, instead of quantitative feature evaluation. Thus, can we say that these enhanced images using ... More
Structure, classifcation, and conformal symmetry, of elementary particles over non-archimedean space-timeMay 08 2009It is known that no length or time measurements are possible in sub-Planckian regions of spacetime. The Volovich hypothesis postulates that the micro-geometry of spacetime may therefore be assumed to be non-archimedean. In this letter, the consequences ... More
Disordered and Ordered States in a Frustrated Anisotropic Heisenberg HamiltonianMar 15 2004We use a recently proposed perturbative numerical renormalization group algorithm to investigate ground-state properties of a frustrated three dimensional Heisenberg model on an anisotropic lattice. We analyze the ground state energy, the finite size ... More
General soliton matrices in the Riemann-Hilbert problem for integrable nonlinear equationsJun 16 2003We derive the soliton matrices corresponding to an arbitrary number of higher-order normal zeros for the matrix Riemann-Hilbert problem of arbitrary matrix dimension, thus giving the complete solution to the problem of higher-order solitons. Our soliton ... More
Duality of metric entropyJul 14 2004For two convex bodies K and T in $R^n$, the covering number of K by T, denoted N(K,T), is defined as the minimal number of translates of T needed to cover K. Let us denote by $K^o$ the polar body of K and by D the euclidean unit ball in $R^n$. We prove ... More
Dark Model Adaptation: Semantic Image Segmentation from Daytime to NighttimeOct 05 2018This work addresses the problem of semantic image segmentation of nighttime scenes. Although considerable progress has been made in semantic image segmentation, it is mainly related to daytime scenarios. This paper proposes a novel method to progressive ... More
Calculation of parity nonconservation in cesium and possible deviation from the Standard ModelNov 02 2001We have calculated the 6s-7s parity nonconserving E1 transition amplitude (E_{PNC}) in cesium. This calculation has been performed with higher numerical accuracy than our 1989 calculation [V.A. Dzuba, V.V. Flambaum, and O.P. Sushkov, Phys. Lett. A {\bf ... More
A 3% Determination of $H_0$ at Intermediate RedshiftsJun 02 2012Dec 10 2013Recent determinations of the Hubble constant, H_0, at extremely low and very high redshifts based on the cosmic distance ladder (grounded with trigonometric parallaxes) and a cosmological model (applied to Planck 2013 data) respectively, are revealing ... More
Transition Redshift: New Kinematic Constraints from SupernovaeMay 09 2008Jul 02 2008The transition redshift (deceleration/acceleration) is discussed by expanding the deceleration parameter to first order around its present value. A detailed study is carried out by considering two different parameterizations: $q=q_0 + q_1z$ and $q=q_0 ... More
Atomic electric dipole moments of He and Yb induced by nuclear Schiff momentsMay 28 2007We have calculated the atomic electric dipole moments (EDMs) d of ^3He and ^{171}Yb induced by their respective nuclear Schiff moments S. Our results are d(He)= 8.3x10^{-5} and d(Yb)= -1.9 in units 10^{-17}S/(e{fm}^3)e cm. By considering the nuclear Schiff ... More
Calculation of parity and time invariance violation in the radium atomDec 14 1999Parity (P) and time (T) invariance violating effects in the Ra atom are strongly enhanced due to close states of opposite parity, the large nuclear charge Z and the collective nature of P,T-odd nuclear moments. We have performed calculations of the atomic ... More
Deflationary cosmology: constraints from angular size and ages of globular clustersFeb 13 2002Jul 02 2002Observational constraints to a large class of decaying vacuum cosmologies are derived using the angular size data of compact radio sources and the latest age estimates of globular clusters. For this class of deflationary $\Lambda(t)$ models, the present ... More
Constraining the dark energy with galaxy clusters X-ray dataMar 17 2003The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest measurements of the ... More
Oscillatory exchange bias and training effects in nanocrystalline Pr0.5Ca0.5MnO3Apr 04 2012We report on exchange bias effects in 10 nm particles of Pr0.5Ca0.5MnO3 which appear as a result of competing interactions between the ferromagnetic (FM)/anti-ferromagnetic (AFM) phases. The fascinating new observation is the demonstration of the temperature ... More
The atomic electric dipole moment induced by the nuclear electric dipole moment; the magnetic moment effectDec 03 2010Mar 02 2011We have considered a mechanism for inducing a time-reversal violating electric dipole moment (EDM) in atoms through the interaction of a nuclear EDM (d_N) with the hyperfine interaction, the "magnetic moment effect". We have derived the operator for this ... More
Image-level Classification in Hyperspectral Images using Feature Descriptors, with Application to Face RecognitionMay 11 2016In this paper, we proposed a novel pipeline for image-level classification in the hyperspectral images. By doing this, we show that the discriminative spectral information at image-level features lead to significantly improved performance in a face recognition ... More
Martensite-like transition and spin-glass behavior in nanocrystalline Pr0.5Ca0.5MnO3Apr 04 2012We report on isothermal pulsed (20 ms) field magnetization, temperature dependent AC - susceptibility, and the static low magnetic field measurements carried out on 10 nm sized Pr0.5Ca0.5MnO3 nanoparticles (PCMO10). The saturation field for the magnetization ... More
Simplified Quartessence CosmologyOct 31 2006Jan 14 2009We propose a new class of accelerating world models unifying the cosmological dark sector (dark matter and dark energy). All the models are described by a simplified version of the Chaplygin gas Quartessence cosmology. It is found that even for $\Omega_k ... More
Cosmological constraints on Chaplygin gas dark energy from galaxy clusters X-ray and supernova dataJun 16 2003Feb 02 2004The recent observational evidences for the present accelerated stage of the Universe have stimulated renewed interest for alternative cosmologies. In general, such models contain an unknown negative-pressure dark component that explains the supernova ... More
A simplified approach for Chaplygin-type cosmologiesAug 22 2006A new class of accelerating cosmological models driven by a one-parameter version of the general Chaplygin-type equation of state is proposed. The simplified version is naturally obtained from causality considerations with basis on the adiabatic sound ... More
Cosmological implications of APM 08279+5255, an old quasar at z = 3.91Jan 13 2003Mar 04 2003The existence of old high-redshift objects provides an important tool for constraining the expanding age of the Universe and the formation epoch of the first objects. In a recent paper, Hasinger {\it et al.} (2002) reported the discovery of the quasar ... More
Calculations of parity nonconserving s-d transitions in Cs, Fr, Ba II, and Ra IIJan 08 2001We have performed ab initio mixed-states and sum-over-states calculations of parity nonconserving (PNC) electric dipole (E1) transition amplitudes between s-d electron states of Cs, Fr, Ba II, and Ra II. For the lower states of these atoms we have also ... More
Precise calculation of parity nonconservation in cesium and test of the standard modelApr 12 2002We have calculated the 6s-7s parity nonconserving (PNC) E1 transition amplitude, E_{PNC}, in cesium. We have used an improved all-order technique in the calculation of the correlations and have included all significant contributions to E_{PNC}. Our final ... More
Deformed Distance Duality Relations and Supernovae DimmingOct 23 2011The basic cosmological distances are linked by the Etherington cosmic distance duality relation, $\eta (z) = D_{L}(z)(1+z)^{-2}/D_{A}(z) \equiv 1$, where $D_{L}$ and $D_{A}$ are, respectively, the luminosity and angular diameter distances. In order to ... More
Magnetocaloric effect and nature of magnetic transition in nanoscale Pr0.5Ca0.5MnO3Sep 27 2012Systematic measurements pertinent to the magnetocaloric effect and nature of magnetic transition around the transition temperature are performed in the 10 nm Pr0.5Ca0.5MnO3 nanoparticles (PCMO10) . Maxwell relation is employed to estimate the change in ... More
Spontaneous currents and half-integer Shapiro steps in Superconductor-Ferromagnet-Superconductor 0-pi Josephson junctionsMay 31 2005We study Superconductor-Ferromagnet-Superconductor (Nb-Cu0.47 Ni0.53-Nb) Josephson junctions with spatial variations in the barrier thickness. Critical current vs. magnetic flux diffraction patterns indicate that the critical current density changes sign ... More
Eclipsing binaries in the Magellanic Clouds. uvby CCD light curves and photometric analyses for HV982 (LMC), HV12578 (LMC), HV1433 (SMC), and HV11284 (SMC)Feb 28 2003We present new accurate CCD uvby light curves for the LMC eclipsing binaries HV982 and HV12578, and for the SMC systems HV1433 and HV11284 obtained at the Danish 1.5m telescope at ESO, La Silla. The light curves were derived from DoPHOT photometry, and ... More
Reddenings and metallicities in the LMC and SMC from Stroemgren CCD photometryDec 01 2000The individual reddenings for B stars in two fields in the Small Magellanic Cloud (SMC) and two fields in the Large Magellanic Cloud (LMC) are determined by means of Stroemgren uvby CCD photometry. In both LMC fields we find a foreground reddening of ... More
Study of Glass and Bakelite properties as electrodes in RPCsApr 14 2016May 11 2016India-based Neutrino Observatory (INO) collaboration is planning to build a magnetized Iron-CALorimeter detector (ICAL) for the study of atmospheric neutrinos. ICAL detector will be a stack of 151 layers of magnetized iron plates interleaved with Resistive ... More
Sunspot Observations during the Maunder Minimum from the Correspondence of John FlamsteedJan 12 2016We compile and analyze the sunspot observations made by John Flamsteed for the period 1672-1703, corresponding to the second part of the Maunder Minimum, which appear in the correspondence of this famous astronomer. We include in an appendix the original ... More
Modeling Hybrid StarsOct 16 2012We study the so called hybrid stars, which are hadronic stars that contain a core of deconfined quarks. For this purpose, we make use of an extended version of the SU(3) chiral model. Within this approach, the degrees of freedom change naturally from ... More
Stripe Liquid, Crystal, and Glass Phases of Doped AntiferromagnetsSep 03 1998A largely descriptive survey is given of the ordered phases of doped antiferromagnets, and of the long wavelength properties that can be derived from an order-parameter theory. In particular, we show that the competition between the long-range Coulomb ... More
Topological Doping of Correlated InsulatorsMar 02 1996A material which is an insulator entirely because of interaction effects is called a correlated insulator. Examples are trans-polyacetylene and the cuprate high temperature superconductors. Whereas doping of a band insulator results in a shift of the ... More
IceCube PeV Cascade Events Initiated by Electron-Antineutrinos at Glashow ResonanceJul 19 2012Feb 03 2013We propose an interpretation of the two neutrino initiated cascade events with PeV energies observed by IceCube: Ultra-high energy cosmic ray protons (or Fe nuclei) scatter on CMB photons through the Delta-resonance (the Berezinsky-Zatsepin process) yielding ... More
Calculations of energy levels and lifetimes of low-lying states of barium and radiumNov 23 2005We use the configuration interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the ... More
Waves and Solitons in the Calogero Model - RevisitedNov 15 2008Feb 13 2010The Calogero model bears, in the continuum limit, collective excitations in the form of density waves and solitary modulations of the density of particles. This sector of the spectrum of the model was investigated, mostly within the framework of collective ... More
Collective Field Formulation of the Multispecies Calogero Model and its Duality SymmetriesNov 14 2006Dec 02 2006We study the collective field formulation of a restricted form of the multispecies Calogero model, in which the three-body interactions are set to zero. We show that the resulting collective field theory is invariant under certain duality transformations, ... More
Generation of Magnetohydrodynamic Waves in Low Solar Atmospheric Flux Tubes by Photospheric MotionsMay 31 2013Nov 07 2014Recent ground- and space-based observations reveal the presence of small-scale motions between convection cells in the solar photosphere. In these regions small-scale magnetic flux tubes are generated due to the interaction of granulation motion and background ... More
Comment on "Generalized black diholes"Oct 01 2014Nov 05 2015We show that a recent solution published by Cabrera-Munguia et al. is physically inconsistent since the quantity $\sigma$ it involves does not have a correct limit $R\to\infty$.
Charging of spinning insulating ob jects by plasma and photoemissionFeb 12 2009The charging of spinning insulating objects by plasma and photoemission is studied with the particle-in-cell method. Unidirectional photon flux, different angular velocities of the object, and different plasma flow speeds are considered. Photoemission ... More
Charge and potential distributions for particles approaching substrates with regular structuresFeb 12 2009The charge and potential distributions for insulating particles approaching a substrate with regular insulating structures are studied by particle-in-cell numerical simulations. An elongated particle and substrate with elongated structures are considered ... More
Limits of control for quantum systems: kinematical bounds on the optimization of observables and the question of dynamical realizabilityOct 07 2000In this paper we investigate the limits of control for mixed-state quantum systems. The constraint of unitary evolution for non-dissipative quantum systems imposes kinematical bounds on the optimization of arbitrary observables. We summarize our previous ... More
Lévy walksOct 19 2014Jan 23 2015Random walk is a fundamental concept with applications ranging from quantum physics to econometrics. Remarkably, one specific model of random walks appears to be ubiquitous across many fields as a tool to analyze transport phenomena in which the dispersal ... More
Scatttering of Weakly Interacting Massive Particles from Ge73Aug 05 1994We use a "hybrid" method, mixing variationally-determined triaxial nuclear Slater determinants, to calculate the response of Ge73 to hypothetical dark-matter particles such as neutralinos. The method is a hybrid in that rotational invariance is approximately ... More
Maximum Elliptical Dichroism in Atomic Two-Photon IonizationAug 06 2018Elliptical dichroism is known in atomic photoionization as the difference in the photoelectron angular distributions produced in nonlinear ionization of atoms by left- and right-handed elliptically polarized light. We theoretically demonstrate that the ... More
Can Old Galaxies at High Redshifts and Baryon Acoustic Oscillations Constrain H_0?Sep 14 2007Sep 15 2007A new age-redshift test is proposed in order to constrain $H_0$ with basis on the existence of old high redshift galaxies (OHRG). As should be expected, the estimates of $H_0$ based on the OHRG are heavily dependent on the cosmological description. In ... More
Infinitely-fast diffusion in Single-File SystemsOct 29 2002We have used Dynamic Monte Carlo (DMC) methods and analytical techniques to analyze Single-File Systems for which diffusion is infinitely-fast. We have simplified the Master Equation removing the fast reactions and we have introduced a DMC algorithm for ... More
Relaxation of Bose-Einstein Condensates of Magnons in Magneto-Textural Traps in Superfluid $^3$He-BJul 25 2013Nov 05 2013In superfluid $^3$He-B externally pumped quantized spin-wave excitations or magnons spontaneously form a Bose-Einstein condensate in a 3-dimensional trap created with the order-parameter texture and a shallow minimum in the polarizing field. The condensation ... More
The Density Matrix Renormalization Group Method for Realistic Large-Scale Nuclear Shell-Model CalculationsJul 11 2002The Density Matrix Renormalization Group (DMRG) method is developed for application to realistic nuclear systems. Test results are reported for 24Mg.
The Density Matrix Renormalization Group Method and Large-Scale Nuclear Shell-Model CalculationsFeb 15 2002The particle-hole Density Matrix Renormalization Group (p-h DMRG) method is discussed as a possible new approach to large-scale nuclear shell-model calculations. Following a general description of the method, we apply it to a class of problems involving ... More
Magnetovolume Effects in Heusler Compounds via First-Principles CalculationsDec 29 2016Heusler alloys are promising for several applications, including magnetic refrigeration, due to high magnetocaloric and magnetovolume effects. One way to optimize this potential is by increasing the magnetovolume effect. Using density functional theory ... More
Pre-main sequence accretion in the low metallicity Galactic star-forming region Sh 2-284Dec 05 2014We present optical spectra of pre-main sequence (PMS) candidates around the H$\alpha$ region taken with the Southern African Large Telescope, SALT, in the low metallicity ($Z$) Galactic region Sh 2-284, which includes the open cluster Dolidze 25 with ... More
Measurements of Protein-Protein Interactions by Size Exclusion ChromatographyJun 12 2003A method is presented for determining second virial coefficients B_2 of protein solutions from retention time measurements in size exclusion chromatography (SEC). We determine B_2 by analyzing the concentration dependance of the chromatographic partition ... More
A Review: Expert System for Diagnosis of Myocardial InfarctionJan 01 2014A computer Program Capable of performing at a human-expert level in a narrow problem domain area is called an expert system. Management of uncertainty is an intrinsically important issue in the design of expert systems because much of the information ... More
Semi-supervised Bootstrapping approach for Named Entity RecognitionNov 21 2015The aim of Named Entity Recognition (NER) is to identify references of named entities in unstructured documents, and to classify them into pre-defined semantic categories. NER often aids from added background knowledge in the form of gazetteers. However ... More
Plasma Magnetosphere Formation Around Oscillating Magnetized Neutron StarsJan 08 2009The notion of death line of rotating pulsars is applied to model of oscillating neutron stars. It is shown that the magnetosphere of typical non-rotating oscillating stars may not contain secondary plasma to support the generation of radio emission in ... More
Local Electronic Structure and High Temperature SuperconductivityFeb 11 1999It is argued that a new mechanism and many-body theory of superconductivity are required for doped correlated insulators. Here we review the essential features of and the experimental support for such a theory, in which the physics is driven by the kinetic ... More
Gravitational waves in an expanding UniverseAug 03 1998We study the tensorial modes of the two-fluid model, where one of this fluids has an equation of state $p = - \rho/3$ (variable cosmological constant, cosmic string fluid, texture) or $p = - \rho$ (cosmological constant), while the other fluid is an ordinary ... More
Simultaneously non-linear energy calibration of CMS calorimeters for single pions and electronsOct 11 2001CMS calorimeter energy calibration was done in the full CMS simulated geometry for the pseudorapidity region eta = 0. The samples of single pion events were generated with a set of incident energies from 5 GeV to 3 TeV and for single electrons from 5 ... More
Non-linear energy calibration of CMS calorimeters for single pionsMar 15 2001CMS calorimeter energy calibration was done in the full CMS simulated geometry for the pseudorapidity region eta = 0. The samples of single pion events were generated with a set of incident energies from 10 GeV to 3 TeV. The analysis of the simulated ... More
Beurling algebra analogues of the classical theorems of Wiener and Levy on absolutely convergent Fourier seriesOct 18 2003Let $f$ be a continuous function on the unit circle $\Gamma$, whose Fourier series is $\omega$-absolutely convergent for some weight $\omega$ on the set of integers $\mathcal{Z}$. If $f$ is nowhere vanishing on $\Gamma$, then there exists a weight $\nu$ ... More
Functional Renormalization Prediction of RuptureNov 09 2000We develop theoretical formulas for the prediction of the rupture of systems which are known to exhibit a critical behavior, based solely on the knowledge of the early time evolution of an observable, such as the acoustic emission rate as a function of ... More
Current Algebra in the Path Integral frameworkJun 09 1998Sep 03 1998In this letter we describe an approach to the current algebra based in the Path Integral formalism. We use this method for abelian and non-abelian quantum field theories in 1+1 and 2+1 dimensions and the correct expressions are obtained. Our results show ... More
Hadron structure and the limitations of phenomenological models in electromagnetic reactionsAug 17 2001The description of electromagnetic reactions at intermediate energies, such as pion electroproduction or (virtual) Compton scattering, traditionally starts from covariant tree-level Feynman diagrams (Born or pole terms). Internal hadron structure is included ... More
A non-separable Christensen's theorem and set tri-quotient mapsJan 11 2008Jan 19 2008For every space $X$ let $\mathcal K(X)$ be the set of all compact subsets of $X$. Christensen \cite{c:74} proved that if $X, Y$ are separable metrizable spaces and $F\colon\mathcal{K}(X)\to\mathcal{K}(Y)$ is a monotone map such that any $L\in\mathcal{K}(Y)$ ... More
A new interaction potential for swarming modelsApr 11 2012Mar 03 2013We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive ... More
Measurement of the Current-Phase Relation of SFS pi-Josephson junctionsFeb 17 2004We present measurements of the current-phase relation (CPR) of Superconductor-Ferromagnet-Superconductor (SFS) Josephson junctions as a function of temperature. The CPR is determined by incorporating the junction into a superconducting loop coupled to ... More
Neutrino masses from nonstandard supersymmetry breaking termsDec 01 1999Dec 09 1999Naturally small Majorana neutrino masses arise from nonstandard supersymmetry breaking terms. This mechanism works in the minimal supersymmetric framework and does not require extra particles or new mass scales. It could also be responsible for proton ... More
Phenomenological aspects of nonstandard supersymmetry breaking termsJun 14 2000In realistic supersymmetric models, very small hard supersymmetry breaking terms generally appear. Some of them violate baryon and/or lepton number. We discuss their possible applications to proton decay and generation of neutrino masses.