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Parametric amplification and noise-squeezing in room temperature atomic vapoursMar 01 2019We report on the use of parametric excitation to coherently manipulate the collective spin state of an atomic vapour at room temperature. Signatures of the parametric excitation are detected in the ground-state spin evolution. These include the excitation ... More

Linear and non-linear coherent coupling in a Bell-Bloom magnetometerMar 13 2019Spin-exchange collisions in hot vapours are generally regarded as a decoherence mechanism. In contrast, we show that linear and non-linear spin-exchange coupling can lead to the generation of atomic coherence in a Bell-Bloom magnetometer. In particular, ... More

Analysis and calibration of absorptive images of Bose-Einstein condensate at non-zero temperaturesNov 25 2008We describe the method allowing quantitative interpretation of absorptive images of mixtures of BEC and thermal atoms which reduces possible systematic errors associated with evaluation of the contribution of each fraction. By using known temperature ... More

Free-fall expansion of finite-temperature Bose-Einstein condensed gas in the non Thomas-Fermi regimeNov 11 2008We report on our study of the free-fall expansion of a finite-temperature Bose-Einstein condensed cloud of 87Rb. The experiments are performed with a variable total number of atoms while keeping constant the number of atoms in the condensate. The results ... More

Experimenting an optical second with strontium lattice clocksJan 25 2013Jul 31 2013Progress in realizing the SI second had multiple technological impacts and enabled to further constraint theoretical models in fundamental physics. Caesium microwave fountains, realizing best the second according to its current definition with a relative ... More

Non-destructive structural imaging of steelwork with atomic magnetometersAug 09 2018We demonstrate the imaging of ferromagnetic carbon steel samples and we detect the thinning of their profile with a sensitivity of 0.1 mm using a Cs radio-frequency atomic magnetometer. Images are obtained at room temperature, in magnetically unscreened ... More

Matter-Wave Interference versus Spontaneous Pattern Formation in Spinor Bose-Einstein CondensateMar 19 2013Aug 25 2013We describe effects of matter-wave interference of spinor states in the $^{87}$Rb Bose-Einstein condensate. The components of the F=2 manifold are populated by forced Majorana transitions and then fall freely due to gravity in an applied magnetic field. ... More

Absolute Frequency Measurement of Rubidium 5S-7S Two-Photon TransitionsNov 14 2013We report the absolute frequency measurements of rubidium 5S-7S two-photon transitions with a cw laser digitally locked to an atomic transition and referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm) insensitive ... More

Natural electroweak symmetry breaking in generalised mirror matter modelsOct 02 2006Nov 28 2006It has recently been pointed out that the mirror or twin Higgs model is more technically natural than the standard model, thus alleviating the ``little'' hierarchy problem. In this paper we generalise the analysis to models with an arbitrary number of ... More

Studies of neutrino asymmetries generated by ordinary-sterile neutrino oscillations in the early universe and implications for big bang nucleosynthesis boundsOct 03 1996Nov 19 1996Ordinary-sterile neutrino oscillations can generate a significant lepton number asymmetry in the early Universe. We study this phenomenon in detail. We show that the dynamics of ordinary-sterile neutrino oscillations in the early Universe can be approximately ... More

Do the SuperKamiokande atmospheric neutrino results explain electric charge quantisation?Aug 24 1998We show that the SuperKamiokande atmospheric neutrino results explain electric charge quantisation, provided that the oscillation mode is $\nu_{\mu} \to \nu_{\tau}$ and that the neutrino mass is of Majorana type.

Neutrino physics and the mirror world: how exact parity symmetry explains the solar neutrino deficit, the atmospheric neutrino anomaly and the LSND experimentMay 23 1995Nov 08 1995Evidence for $\bar \nu_{\mu} \rightarrow \bar \nu_e$ oscillations has been reported at LAMPF using the LSND detector. Further evidence for neutrino mixing comes from the solar neutrino deficit and the atmospheric neutrino anomaly. All of these anomalies ... More

Was ordinary matter synthesised from mirror matter? An attempt to explain why $Ω_{Baryon} \approx 0.2Ω_{Dark}$Apr 28 2003Jun 03 2003The cosmological dust has begun to settle. A likely picture is a universe comprised (predominantly) of three components: ordinary baryons ($\Omega_B \approx 0.05$), non-baryonic dark matter ($\Omega_{Dark} \approx 0.22$) and dark energy ($\Omega_{\Lambda} ... More

How neutrino oscillations can induce an effective neutrino number of less than 3 during Big Bang NucleosynthesisJun 04 1997Ordinary-sterile neutrino oscillations can generate significant neutrino asymmetry in the early Universe. In this paper we extend this work by computing the evolution of neutrino asymmetries and light element abundances during the Big Bang Nucleosynthesis ... More

Maximal neutrino oscillation solution to the solar neutrino problemOct 17 1995We discuss a simple predictive solution to the solar neutrino problem based on maximal vacuum neutrino oscillations. The solution can be motivated by the exact parity symmetric model which predicts that the neutrino mass eigenstates are maximal mixtures ... More

A mirror world explanation for the Pioneer spacecraft anomalies?Aug 06 2001We show that the anomalous acceleration of the Pioneer 10/11 spacecraft can be explained if there is some mirror gas or mirror dust in our solar system.

The exact parity symmetric model and big bang nucleosynthesisDec 04 1996The assumption of exact, unbroken parity symmetry leads directly to a simple predictive resolution of the atmospheric and solar neutrino puzzles. This is because the existence of this symmetry implies the existence of a set of mirror neutrinos which must ... More

Comment on "Big Bang Nucleosynthesis and Active-Sterile Neutrino Mixing: Evidence for Maximal $ν_μ\leftrightarrow ν_τ$ Mixing in Super Kamiokande?"Nov 04 1998The paper "Big Bang Nucleosynthesis and Active-Sterile Neutrino Mixing: Evidence for Maximal $\nu_\mu \leftrightarrow \nu_\tau$ Mixing in Super Kamiokande?" by X. Shi and G. M. Fuller (astro-ph/9810075) discusses the cosmological implications of the $\nu_\mu ... More

Explaining $Ω_{Baryon} \approx 0.2 Ω_{Dark}$ through the synthesis of ordinary matter from mirror matter: a more general analysisFeb 25 2004Mar 25 2004The emerging cosmological picture is of a spatially flat universe composed predominantly of three components: ordinary baryons ($\Omega_B \approx 0.05$), non-baryonic dark matter ($\Omega_{Dark} \approx 0.22$) and dark energy ($\Omega_{\Lambda} \approx ... More

The neutrino puzzle in the light of SNOApr 23 2002Jul 23 2002SNO's neutral current measurement has added a new piece to the emerging neutrino physics puzzle. Putting together the presently available experimental information, an essentially unique picture emerges: The solar neutrino anomaly is explained by nu_e ... More

Spheroidal galactic halos and mirror dark matterJul 26 2004Mirror matter has been proposed as a dark matter candidate. It has several very attractive features, including automatic stability and darkness, the ability to mimic the broad features of cold dark matter while in the linear density perturbation regime, ... More

New and improved quark-lepton symmetric modelsMay 18 1995We show how the use of a see-saw mechanism based on a $3 \times 3$ neutrino mass matrix texture can considerably simplify Higgs sectors for quark-lepton symmetric models (and for Standard Model extensions generally). The main theory we discuss also incorporates ... More

Reconciling sterile neutrinos with big bang nucleosynthesisAug 10 1995Nov 08 1995We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of neutrinos with sterile species. These bounds depend on the assumption that the relic neutrino asymmetry $L_{\nu}$ is very small. We show that for $L_{\nu}$ large enough (greater ... More

Implications of mirror neutrinos for early universe cosmologyApr 15 1999The Exact Parity Model (EPM) is, in part, a theory of neutrino mass and mixing that can solve the atmospheric, solar and LSND anomalies. The central feature of the neutrino sector is three pairs of maximally mixed ordinary and mirror neutrinos. It has ... More

Generalised leptonic colourJul 05 2006Dec 06 2006It is conceivable that there is an $SU(N)_{\ell}$ `colour' gauge group for leptons, analogous to the gauged $SU(3)_q$ colour group of the quarks. The standard model emerges as the low energy effective theory when the leptonic colour is spontaneously broken. ... More

Effective Theory for Color-Flavor Locking in high Density QCDAug 03 1999Sep 06 1999We describe the low energy excitations of the diquark condensates in the color-flavor locked phase of QCD with three massless flavors, at high baryon densities, in terms of a non-linear effective lagrangian. Such a lagrangian is formally seen to correspond ... More

Full operators and algebras generated by invertible operatorsApr 10 2009Oct 22 2009In the present work we characterized full operators and we showed some properties that have nonfull injectives operators. With the results developed for full operators, we affirmatively respond two questions formulated by Bravo and Feintuch on when the ... More

Landau Levels in the noncommutative $AdS_2$Nov 22 2001Feb 15 2002We formulate the Landau problem in the context of the noncommutative analog of a surface of constant negative curvature, that is $AdS_2$ surface, and obtain the spectrum and contrast the same with the Landau levels one finds in the case of the commutative ... More

(p,q)-Rogers-Szego polynomial and the (p,q)-oscillatorMay 24 2010A (p,q)-analogue of the classical Rogers-Szego polynomial is defined by replacing the q-binomial coefficient in it by the (p,q)-binomial coefficient. Exactly like the Rogers-Szego polynomial is associated with the q-oscillator algebra it is found that ... More

Vacuum Cherenkov radiation in Maxwell-Chern-Simons electrodynamicsNov 22 2005We study the Cherenkov effect in the context of the Maxwell-Chern-Simons (MCS) limit of the Standard Model Extension. We present a method to determine the exact radiation rate for a point charge.

On Spin-Statistics and Bogoliubov Transformations in Flat Spacetime With Acceleration ConditionsMay 04 2012Jan 31 2013A single real scalar field of spin zero obeying the Klein-Gordon equation in flat space-time under external conditions is considered in the context of the spin-statistics connection. An imposed accelerated boundary on the field is made to become, in the ... More

Finite-dimensional Calogero representation of the $q$-differential operatorApr 24 1995A finite-dimensional matrix representation of the Jackson $q$-differential operator $D_q$, defined by $D_qf(x)$ $=$ $(f(qx)-f(x))/(x(q-1))$, is written down following Calogero. Such a representation of $D_q$ should have applications in $q$-analysis leading ... More

Early Objects in the Cosmic String Theory with Hot Dark MatterJan 27 1997We study the accretion of hot dark matter onto moving cosmic string loops, using an adaptation of the Zeldovich approximation to HDM. We show that a large number of nonlinear objects of mass greater than $10^{12}M_\odot$, which could be the hosts of high ... More

Supersymmetry in Thermo Field DynamicsJun 21 2000By considering the enlarged thermal system including the heat bath, it is shown that this system has supersymmetry which is not broken at finite temperature. The super algebra is constructed and the Hamiltonian is expressed as the anti-commutator of two ... More

Very Big Accelerators as Energy ProducersJul 29 2010One consequence of the application of superconductivity to accelerator construction is that the power consumption of accelerators will become much smaller. This raises the old possibility of using high energy protons to make neutrons which are then absorbed ... More

Positive Linear Maps and Perturbation bounds of MatricesSep 18 2015We show how positive unital linear maps can be used to obtain lower bounds for the maximum distance between the eigenvalues of two normal matrices. Some related bounds for the spread and condition number of Hermitian matrices are also discussed here.

Legendrian contact homology and topological entropySep 12 2014Oct 15 2016In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More

The Repeated Solicitation ModelAug 11 1998Sep 15 1998This paper presents a probabilistic analysis of what we call the "repeated solicitation model". To give a specific context, suppose B is a direct marketing company with a list of S sales prospects. At epoch 1, B sends a solicitation to every prospect ... More

The Four Point Permutation Test for Latent Block Structure in Incidence MatricesOct 04 2018Transactional data may be represented as a bipartite graph $G:=(L \cup R, E)$, where $L$ denotes agents, $R$ denotes objects visible to many agents, and an edge in $E$ denotes an interaction between an agent and an object. Unsupervised learning seeks ... More

Legendrian contact homology and topological entropySep 12 2014Apr 23 2016In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More

The heat-kernel and the average effective potentialMay 29 1995We discuss the definition of the average effective action in terms of the heat-kernel. As an example we examine a model describing a self-interacting scalar field, both in flat and curved background, and study the renormalization group flow of some of ... More

The renormalization group flow of the dilaton potentialDec 20 1994We consider a scalar-metric gauge theory of gravity with independent metric, connection and dilaton. The role of the dilaton is to provide the scale of all masses, via its vacuum expectation value. In this theory, we study the renormalization group flow ... More

Ordinary-derivative formulation of conformal low-spin fieldsJul 30 2007Nov 14 2011Conformal fields in flat space-time of even dimension greater than or equal to four are studied. Second-derivative formulation for spin 0,1,2 conformal bosonic fields and first-derivative formulation for spin 1/2,3/2 conformal fermionic fields are developed. ... More

Gravitational and higher-derivative interactions of massive spin 5/2 field in (A)dS spaceDec 27 2006Sep 10 2007Using on-shell gauge invariant formulation of relativistic dynamics we study interaction vertices for a massive spin 5/2 Dirac field propagating in (A)dS space of dimension greater than or equal to four. Gravitational interaction vertex for the massive ... More

CFT adapted gauge invariant formulation of arbitrary spin fields in AdS and modified de Donder gaugeAug 28 2008Jan 22 2009Using Poincare parametrization of AdS space, we study totally symmetric arbitrary spin massless fields in AdS space of dimension greater than or equal to four. CFT adapted gauge invariant formulation for such fields is developed. Gauge symmetries are ... More

CFT adapted approach to massless fermionic fields, AdS/CFT, and fermionic conformal fieldsNov 28 2013Dec 10 2013Fermionic totally symmetric arbitrary spin massless fields in AdS space of dimension greater than or equal to four are studied. Using Poincar\'e parametrization of AdS space, CFT adapted gauge invariant formulation for such fields is developed. We demonstrate ... More

The Color-Flavor Locking Phase at T \not =0$Sep 17 1999Nov 03 1999We study the color-flavor locked phase of QCD with three massless quarks at high chemical potential and small non zero temperatures. We make use of the recently introduced effective action to describe such a phase. We obtain the exact order T^2 behaviour ... More

Preliminary Investigation of a Waveform Analysis with the WASA and the ACQIRIS Readout ElectronicsJun 28 2013Jul 16 2013The Group for the development of neutron and gamma detectors in the Central Institute of Engineering, Electronics and Analytics (ZEA-2) at Forschungszentrum J\"ulich (FZJ) is developing a fast Anger Camera prototype for improving the rejection of the ... More

TARCER - A Mathematica program for the reduction of two-loop propagator integralsJan 21 1998TARCER is an implementation of the recurrence algorithm of O.V. Tarasov for the reduction of two-loop propagator integrals with arbitrary masses to a small set of basis integrals. The tensor integral reduction scheme is adapted to moment integrals emerging ... More

Implications of the JHF-Kamioka neutrino oscillation experimentNov 20 2002After quickly reviewing the existing evidence for neutrino oscillations, I summarise the goals and capabilities of the JHF-Kamioka long baseline superbeam experiment. Theoretical implications of what this experiment could potentially discover are then ... More

Testing the paradigm of adiabaticityFeb 02 2004We introduce the concepts of adiabatic (curvature) and isocurvature (entropy) cosmological perturbations and present their relevance for parameter estimation from cosmic microwave background anisotropies data. We emphasize that, while present-day data ... More

Automated Checking and Visualization of Interlocks in the ISAC Control SystemNov 09 2001The EPICS based control system of the ISAC radioactive beam facility supervises several sub-systems, which are controlled by PLCs. Most of the devices are protected by non-trivial interlocks, which are implemented with ladder-logic software. Detailed ... More

On the q-analogues of the Zassenhaus formula for dientangling exponential operatorsDec 24 2002Apr 28 2003Katriel, Rasetti and Solomon introduced a $q$-analogue of the Zassenhaus formula written as $e_q^{(A+B)}$ $=$ $e_q^Ae_q^Be_q^{c_2}e_q^{c_3}e_q^{c_4}e_q^{c_5}...$, where $A$ and $B$ are two generally noncommuting operators and $e_q^z$ is the Jackson $q$-exponential, ... More

An Algorithm for the Microscopic Evaluation of the Coefficients of the Seiberg-Witten PrepotentialAug 25 2002Sep 14 2002A procedure, allowing to calculate the coefficients of the SW prepotential in the framework of the instanton calculus is presented. As a demonstration explicit calculations for 2, 3 and 4- instanton contributions are carried out.

Thermostatistics of extensive and non-extensive systems using generalized entropiesMay 04 2000We describe in detail two numerical simulation methods valid to study systems whose thermostatistics is described by generalized entropies, such as Tsallis. The methods are useful for applications to non-trivial interacting systems with a large number ... More

Extremal size fluctuations in QCD dipole cascadingFeb 07 2005Oct 28 2005This paper has been superseded by hep-ph/0510352.

Free Fields Equations For Space-Time Algebras With Tensorial MomentumDec 25 2001Free field equations, with various spins, for space-time algebras with second-rank tensor (instead of usual vector) momentum are constructed. Similar algebras are appearing in superstring/M theories. The most attention is payed to the gauge invariance ... More

On the Evolution of Scalar Metric Perturbations in an Inflationary CosmologySep 15 1995We further clarify how scalar metric perturbations are amplified in an inflationary cosmology. We first construct a simple, analytic model of an inflationary cosmology in which the expansion scale factor evolves continuously from an inflationary era to ... More

Breakup Reactions of Drip Line NucleiOct 18 2003Oct 28 2003The formal theory of breakup reactions is reviewed. The direct breakup mechanism which is formulated within the framework of the post form distorted wave Born approximation is discussed in detail. In this theory, which requires the information about only ... More

Skewness, kurtosis and Newton's inequalitySep 11 2013Feb 21 2014We show that an inequality related to Newton's inequality provides one more relation between skewness and kurtosis. This also gives simple and alternative proofs of the bounds for skewness and kurtosis.

Fluid Limits of Pure Jump Markov Processes: a Practical GuideOct 08 2002Dec 23 2002A rescaled Markov chain converges uniformly in probability to the solution of an ordinary differential equation, under carefully specified assumptions. The presentation is much simpler than those in the outside literature. The result may be used to build ... More

Comments on turbulence theory by Qian and by Edwards and McCombJul 04 2015We reexamine Liouville equation based turbulence theories proposed by Qian {[}Phys. Fluids \textbf{26}, 2098 (1983){]} and Edwards and McComb {[}J. Phys. A: Math. Gen. \textbf{2}, 157 (1969){]}, which are compatible with Kolmogorov spectrum. These theories ... More

On Generalised Inflations of Right Modular GroupoidsNov 03 2012We prove that if a right modular groupoid U is cancellative or has a left identity then a right modular generalised inflation of U is an inflation of U.

Groupoids Determined by Involutive Automorphisms on Semilattices of GroupsMar 01 2015Jun 02 2017We give several characterisations of groupoids determined by involutive automorphisms on semilattices of groups.

Legendrian contact homology and topological entropySep 12 2014May 08 2017In this paper we study the growth rate of a version of Legendrian contact homology, which we call strip Legendrian contact homology, in 3-dimensional contact manifolds and its relation to the topological entropy of Reeb flows. We show that: if for a pair ... More

On the Damping Rate of a Fast Fermion in Hot QEDMar 22 1994The self-consistent determination of the damping rate of a fast moving fermion in a hot QED plasma is reexamined. We argue how a detailed investigation of the analytic properties of the retarded fermion Green's function motivated by the cutting rules ... More

Simulated Annealing using Hybrid Monte CarloJun 06 1997Jul 31 1997We propose a variant of the Simulated Annealing method for optimization in the multivariate analysis of differentiable functions. The method uses global actualizations via the Hybrid Monte Carlo algorithm in their generalized version for the proposal ... More

Gravity is indeed the driving force for fault pattern formation and westward displacement of the lithosphereMay 04 2005May 04 2005Gravity influence of the Sun and the Moon on the Earth is the cause of the fault pattern on Earth's surface we observe nowadays and also of the westward displacement of the lithosphere. A somewhat related hypotheses advanced in the past have been that ... More

On the Laplace equation in d-dimensionJan 22 2009Feb 12 2009We develop a method to obtain the general solution of the Laplace equation in $d$-dimension in ultraspherical coordinates.

Self-Organizing Height-Arrow Model: Numerical and Analytical ResultsAug 02 1997The recently introduced self-organizing height-arrow (HA) model is numerically investigated on the square lattice and analytically on the Bethe lattice. The concentration of occupied sites and critical exponents of distributions of avalanches are evaluated ... More

Coulomb-nuclear interference in the breakup of $^{11}$BeNov 13 2002Within a theory of breakup reactions formulated in the framework of the post form distorted wave Born approximation, we calculate contributions of the pure Coulomb and the pure nuclear breakup as well as those of their interference terms to a variety ... More

On the Hopf structure of $U_{p,q}(gl(1|1))$ and the universal ${\cal T}$-matrix of $Fun_{p,q}(GL(1|1))$Sep 27 1994Using the technique developed by Fronsdal and Galindo (Lett. Math. Phys. 27 (1993) 57) for studying the Hopf duality between the quantum algebras $Fun_{p,q}(GL(2))$ and $U_{p,q}(gl(2))$, the Hopf structure of $U_{p,q}(gl(1|1))$, dual to $Fun_{p,q}(GL(1|1))$, ... More

Metallic behavior at YBaCuO7/ZAs interfaces (Z=Ga, Al)Aug 07 2012We present the electronic band structure of the interfaces $YBa_2Cu_3O_7/GaAs$ (direct gap) and $YBa_2Cu_3O_7/AlAs$ (indirect gap) in different configurations calculated using the Density Functional Theory as in the Wien2k code within the local density ... More

Energy dissipation rate limits for flow through rough channels and tidal flow across topographyAug 03 2016An upper bound on the energy dissipation rate per unit mass, $\epsilon$, for pressure-driven flow through a channel with rough walls is derived for the first time. For large Reynolds numbers, $Re$, the bound - $\epsilon \,\leq \, c\, U^3/h$ where $U$ ... More

Conformal totally symmetric arbitrary spin fermionic fieldsNov 19 2012Conformal totally symmetric arbitrary spin fermionic fields in flat space-time of even dimension greater than or equal to four are studied. First-derivative formulation involving Fang-Fronsdal kinetic operator for such fields is developed. Gauge invariant ... More

Superfield formulation of N=4 Super Yang-Mills theory in plane wave backgroundJan 03 2003Mar 02 2003The superfield light cone gauge formulation of $\cN =4$ SYM in plane wave background is developed. We find a realization of superconformal symmetries in terms of a light cone superfield. An oscillator realization of superconformal symmetries is also obtained. ... More

6d conformal gravityDec 09 2010Jun 28 2011In the framework of ordinary-derivative approach, conformal gravity in space-time of dimension six is studied. The field content, in addition to conformal graviton field, includes two auxiliary rank-2 symmetric tensor fields, two Stueckelberg vector fields ... More

Eleven dimensional supergravity in light cone gaugeOct 25 2004Mar 03 2005Light-cone gauge manifestly supersymmetric formulation of eleven dimensional supergravity is developed. The formulation is given entirely in terms of light cone scalar superfield, allowing us to treat all component fields on an equal footing. All higher ... More

Light-cone AdS/CFT-adapted approach to AdS fields/currents, shadows, and conformal fieldsJul 23 2015Aug 11 2016Light-cone gauge formulation of fields in AdS space and conformal field theory in flat space adapted for the study of AdS/CFT correspondence is developed. Arbitrary spin mixed-symmetry fields in AdS space and arbitrary spin mixed-symmetry currents, shadows, ... More

Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFTOct 27 2014Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous ... More

Pseudoscalar Masses in the Effective Theory for Color-Flavor Locking in high density QCDNov 03 1999The constants of the effective action describing the massless modes in the color-flavor-locking phase of QCD have been recently evaluated at high density. Values of the pseudoscalar masses for nonvanishing quark masses have also been given. The calculated ... More

On the Numerical Solution of the Time-Dependent Schroedinger EquationJul 05 1995An algorithm for the numerical solution of the Schr\"odinger equation in the case of a time dependent potential is proposed. Our simple modification upgrades the well known method of Koonin while negligibly increasing the computing time. In the presented ... More

Black Strings and p-Branes are UnstableJan 13 1993Jan 15 1993We investigate the evolution of small perturbations around black strings and branes which are low energy solutions of string theory. For simplicity we focus attention on the zero charge case and show that there are unstable modes for a range of time frequency ... More

Logic programming as quantum measurementJun 29 1995The emphasis is made on the juxtaposition of (quantum~theorem) proving versus quantum (theorem~proving). The logical contents of verification of the statements concerning quantum systems is outlined. The Zittereingang (trembling input) principle is introduced ... More

MATRIX MODELS FOR SPACETIME TOPODYNAMICSApr 01 1995Apr 06 1995The machinery is suggested to describe the varying spacetime topology on the level of its substitutes by finite topological spaces.

Logico-algebraic approach to spacetime quantizationMar 20 1995In the last decades the logico-algebraic approach to quantum mechanics turned to be a successful tool to render the quantum mechanical formalism on a steady operationalistic background. The algebraic approach to general relativity first proposed by Geroch ... More

New issues in quark-lepton symmetryJul 18 1995Two models incorporating different forms of spontaneously broken quark-lepton symmetry are discussed. Both models are constructed so that quark-lepton symmetry can be broken at as low an energy scale as phenomenology allows, thus maximising their testability. ... More

Neutrino-antineutrino asymmetry in the early universeDec 18 1996In this talk I discuss the use of a relic neutrino-antineutrino asymmetry in suppressing active-sterile neutrino oscillations in the early universe. This phenomenon can serve to greatly loosen the well known Big Bang Nucleosynthesis constraints on active-sterile ... More

Field redefinitions and massive BF models in arbitrary space-time dimensionsAug 31 2001May 13 2002We show that the topological massive BF theories can be written as a pure BF term through field redefinitions. The fields are rewritten as power expansion series in the inverse of the mass parameter $m$. We also give a cohomological justification of this ... More

A Note on Representations of N=2 SW-AlgebrasJul 13 1994We investigate the representation theory of some recently constructed N=2 super W-algebras with two generators. Except for the central charges in the unitary minimal series of the N=2 super Virasoro algebra we find no new rational models. However, from ... More

Local Hidden Variable Theoretic Measure of Quantumness of Mutual InformationSep 30 2014Entanglement, a manifestation of quantumness of correlations between the observables of the subsystems of a composite system, and the quantumness of their mutual information are widely studied characteristics of a system of spin-1/2 particles. The concept ... More

Non-adiabatic radiative collapse of a relativistic star under different initial conditionsJun 25 2012We examine the role of space-time geometry in the non-adiabatic collapse of a star dissipating energy in the form of radial heat flow, studying its evolution under different initial conditions. The collapse of a star with interior comprising of a homogeneous ... More

A q-Generalization of Product Densities and Janossy Functions in Stochastic Point ProcessesMar 30 2004A q-generalization of the product densities in stochastic point processes is developed. The properties of these functions are studied and a q-generalization of the usual $C^r_s$ coefficients is obtained. This for fixed q-number of particles coincides ... More

Quadratic Hyperbolicity Preservers & Multiplier SequencesApr 06 2013It is known (see \cite[Br\"and\'en, Lemma 2.7]{B10}) that a necessary condition for $T:=\sum Q_k(x) D^k$ to be hyperbolicity preserving is that $Q_k(x)$ and $Q_{k-1}(x)$ have interlacing zeros. We characterize all quadratic linear operators, as a consequence ... More

Gravitation of the Casimir Effect and the Cosmological Non-ConstantSep 16 2002Whereas the total energy in zero-point fluctuations of the particle physics vacuum gives rise to the cosmological constant problem, differences in the vacuum give rise to real physical phenomena, such as the Casimir effect. Hence we consider the zero-point ... More

Fuzzy Gamma-hypersemigroupsSep 18 2013We introduced and study fuzzy gamma-hypersemigroups, according to fuzzy semihyper- groups as previously defined [33] and prove that results in this respect. In this regard first we introduce fuzzy hyperoperation and then study fuzzy gamma-hypersemigroup. ... More

Finitary Algebraic SuperspaceApr 23 1997An algebraic scheme is suggested in which discretized spacetime turns out to be a quantum observable. As an example, a toy model producing spacetimes of four points with different topologies is presented. The possibility of incorporating this scheme into ... More

Isospectral flat 3-manifoldsJan 26 2004There is a well-known problem about isospectrality of Riemannian manifolds: whether isospectral manifolds are isometric. In this work we give an answer to this problem for 3-dimensional compact flat manifolds.

Space-time inhomogeneity, anisotropy and gravitational collapseJun 24 2012We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size ... More

Overtwisted energy-minimizing curl eigenfieldsNov 14 2004Sep 11 2015We consider energy-minimizing divergence-free eigenfields of the curl operator in dimension three from the perspective of contact topology. We give a negative answer to a question of Etnyre and the first author by constructing curl eigenfields which minimize ... More