Results for "O. Bayrak"

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Any $l$-state solutions of the Hulthén potential by the asymptotic iteration methodSep 05 2006In this article, we present the analytical solution of the radial Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of the asymptotic iteration method by using an approximation to the centrifugal potential for any $l$ states. ... More
Corrected Analytical Solution of the Generalized Woods-Saxon Potential for Arbitrary $\ell$ StatesJan 13 2015The bound state solution of the radial Schr\"{o}dinger equation with the generalized Woods-Saxon potential is carefully examined by using the Pekeris approximation for arbitrary $\ell$ states. The energy eigenvalues and the corresponding eigenfunctions ... More
Exact bound state solution of the Klein Gordon equation with a position-energy dependent mass and a Coulomb-like energy dependent potential energyJul 10 2019In this manuscript, we investigate the exact bound state solution of the Klein Gordon equation with an energy-dependent Coulomb-like potential energy in the presence of position-energy dependent mass. First, we examine the case where the mixed vector ... More
Solution of the Radial Schrödinger Equation for the Potential Family $V(r)=\frac{A}{r^{2}}-\frac{B}{r}+Cr^κ$ using the Asymptotic Iteration MethodMar 13 2007We present the exact and iterative solutions of the radial Schr\"{o}dinger equation for a class of potential, $V(r)=\frac{A}{r^{2}}-\frac{B}{r}+Cr^{\kappa}$, for various values of $\kappa$ from -2 to 2, for any $n$ and $l$ quantum states by applying the ... More
Special Smarandache Curves in E1 3Apr 25 2012Nov 16 2012In this study, we determine some special Smarandache curves in E1 3.We give some characterizations consequences of Smarandache curves.
Soft Γ-SemiringsFeb 07 2012In this paper, the definitions of soft {\Gamma}-semirings and soft sub {\Gamma}-semi rings are introduced with the aid of the concept of soft set theory introduced by Molodtsov. In the mean time, some of their properties and structural characteristics ... More
Supercritical instability of Dirac electrons in the field of two oppositely charged nucleiSep 29 2016The Dirac equation for an electron in a finite dipole potential has been studied within the method of linear combination of atomic orbitals (LCAO). The Coulomb potential of the nuclei that compose a dipole is regularized, by considering the finite nuclear ... More
Can a gravitational wave and a magnetic monopole coexist?Aug 06 1997Nov 17 1997We investigate the behavior of small perturbations around the Kaluza-Klein monopole in the five dimensional space-time. We find that the even parity gravitational wave does not propagate in the five dimensional space-time with Kaluza-Klein monopole provided ... More
Superhard Phases of Simple Substances and Binary Compounds of the B-C-N-O System: from Diamond to the Latest Results (a Review)Jan 15 2011The basic known and hypothetic one- and two-element phases of the B-C-N-O system (both superhard phases having diamond and boron structures and precursors to synthesize them) are described. The attention has been given to the structure, basic mechanical ... More
On self-similar solutions of the vortex filament equationMar 05 2019We study self-similar solutions of the binormal curvature flow which governs the evolution of vortex filaments and is equivalent to the Landau-Lifshitz equation. The corresponding dynamics is described by the real solutions of $\sigma$-Painlev\'{e} IV ... More
Electrical conductivity of hot Abelian plasma with scalar charge carriersMay 20 2019We study the electrical conductivity of hot Abelian plasma containing scalar charge carriers in the leading logarithmic order in coupling constant $\alpha$ using the Boltzmann kinetic equation. The leading contribution to the collision integral is due ... More
Quantum singularities in (2+1) dimensional matter coupled black hole spacetimesApr 15 2010Sep 16 2010Quantum singularities considered in the 3D BTZ spacetime by Pitelli and Letelier (Phys. Rev. D77: 124030, 2008) is extended to charged BTZ and 3D Einstein-Maxwell-dilaton gravity spacetimes. The occurence of naked singularities in the Einstein-Maxwell ... More
On Groups with a Supercomplemented SubgroupOct 05 2007Groups, in which every subgroup containing some fixed primary cyclic subgroup has a complement, are investigated.
Condensation temperature of interacting Bose gases with and without disorderApr 24 2006The momentum-shell renormalization group (RG) is used to study the condensation of interacting Bose gases without and with disorder. First of all, for the homogeneous disorder-free Bose gas the interaction-induced shifts in the critical temperature and ... More
LHC Results Highlights (CLASHEP 2013)Jul 26 2013The good performance of the LHC provided enough data at 7 TeV and 8 TeV to allow the experiments to perform very competitive measurements and to expand the knowledge about the fundamental interaction far beyond that from previous colliders. This report ... More
Determination of the strong coupling constant using subjet multiplicities in Neutral Current Deep Inelastic ScatteringNov 22 2001The internal structure of the jets produced in neutral current interactions for Q^2>125 GeV^2 has been studied using the subjet multiplicity with the ZEUS detector at HERA. Jets are identified in the laboratory frame by applying the longitudinally invariant ... More
Migdal's model and holographyJan 23 2007May 29 2007Migdal's model on the spectrum of vector mesons is reassessed. We discuss how its departure from a Pade approximant is closely linked to the issue of quark-hadron duality breakdown. We also show that Migdal's model is not truly a model of large-Nc QCD. ... More
Photospheric processes and magnetic flux tubesSep 01 2007In the first part of these lecture notes, new high-resolution observations of small-scale magnetic flux concentrations are presented and compared to results from new three-dimensional magnetohydrodynamic simulations. Special attention is paid to the physics ... More
Transverse Double-Spin Asymmetries for Dimuon Production in pp CollisionsMay 29 1999Oct 25 1999We calculate the transverse double-spin asymmetry for the production of dimuons in pp collisions as function of the dimuon rapidity and mass to next-to-leading accuracy in the strong coupling. Predictions for BNL-RHIC and HERA-N are made by assuming a ... More
On Witten's global anomaly for higher SU(2) representationsSep 02 2002The spectral flow of the overlap operator is computed numerically along a path connecting two gauge fields which differ by a topologically non-trivial gauge transformation. The calculation is performed for SU(2) in the 3/2 and 5/2 representation. An even-odd ... More
Study of predominant hadronic modes of $τ$-lepton using a Monte Carlo generator TAUOLAJun 28 2015Aug 22 2015TAUOLA is a Monte Carlo generator dedicated to generating tau-lepton decays and it is used in the analysis of experimental data both at B-factories and LHC. TAUOLA is a long-term project that started in the 90's and has been under development up to now. ... More
Evolution of electric-field-induced quasibound states and resonances in one-dimensional open quantum systemsNov 01 2016A comparative analysis of three different time-independent approaches to studying open quantum structures in uniform electric field $\mathscr{E}$ was performed using the example of one-dimensional attractive or repulsive $\delta$-potential and surface ... More
Three Key Tests to GravityJun 20 2003Three presumably unrelated open questions concerning gravity and the structure of the Universe are here discussed: 1) To which extent is Lorentz invariance an exact symmetry ? 2) What is the equation of state of the Universe ? 3) What is the origin of ... More
Is Minisuperspace Quantum Gravity Reliable?Jan 27 2001Feb 13 2001We study a minisuperspace quantum cosmology for a 2+1 dimensional de Sitter universe and find the wave function both exactly and in WKB approximation. Then we extend the model to a canonically quantized field theory for quantum gravity, i.e., a midisuperspace, ... More
Diagnostic of stellar magnetic fields with cumulative circular polarisation profilesMay 27 2015Information about stellar magnetic field topologies is obtained primarily from high-resolution circular polarisation (Stokes $V$) observations. Due to their generally complex morphologies, the stellar Stokes $V$ profiles are usually interpreted with elaborate ... More
Variation of the line profile moments for stars pulsating in distorted oblique non-radial modesMar 21 2005We derive expressions and develop a numerical technique for the analysis of the line profile moment variations for stars pulsating in oblique non-radial modes. This represents an extension of the widely used spectroscopic moment mode identification method ... More
Social Behaviour of Agents: Capital Markets and Their Small PerturbationsMay 11 2005We study social behaviour of agents on capital markets when these are perturbed by small perturbations. We use the mean field method. Social behaviour of agents on capital markets is described: volatility of the market, aversion constant and equilibrium ... More
Landau theory of 180 degrees domain walls in BaTiO3 type ferroelectric particles: microcomposite materialsApr 27 2005Apr 27 2005The Landau theory of 180 degrees domain walls in BaTiO3 type ferroelectric particles is presented. Results of exact description of domain walls in bulk enabled us to formulate variational approach to theory of domain walls in corresponding small particles. ... More
Percolation thresholds on planar Euclidean relative neighborhood graphsJan 29 2013In the presented article, statistical properties regarding the topology and standard percolation on relative neighborhood graphs (RNGs) for planar sets of points, considering the Euclidean metric, are put under scrutiny. RNGs belong to the family of ``proximity ... More
Post-Riemannian Spacetimes Admit a Causal StructureJun 22 1997Apr 20 1999Paper withdrawn due to conceptual mistakes. A corrected version will soon be available at the gr-qc archive.
Theory of the Robin quantum wall in a linear potential. I. Energy spectrum, polarization and quantum-information measuresMay 10 2016Information-theoretical concepts are employed for the analysis of the interplay between a transverse electric field $\mathscr{E}$ applied to a one-dimensional surface and Robin boundary condition (BC), which with the help of the extrapolation length $\Lambda$ ... More
Comparative analysis of electric field influence on the quantum wells with different boundary conditions. I. Energy spectrum, quantum information entropy and polarizationFeb 10 2015Apr 07 2015Analytical solutions of the Schr\"{o}dinger equation for the one-dimensional quantum well with all possible permutations of the Dirichlet and Neumann boundary conditions (BCs) in perpendicular to the interfaces uniform electric field $\mathscr{E}$ are ... More
On eigenvalue distribution of random matrices of Ihara zeta function of large random graphsAug 31 2015Oct 07 2016We consider the ensemble of real symmetric random matrices $H^{(n,\rho)}$ obtained from the determinant form of the Ihara zeta function of random graphs that have $n$ vertices with the edge probability $\rho/n$. We prove that the normalized eigenvalue ... More
On Borel summation and Stokes phenomena of nonlinear differential systemsAug 16 2006In this paper we study analytic (linear or) nonlinear systems of ordinary differential equations, at an irregular singularity of rank one, under nonresonance conditions. It is shown that the formal asymptotic exponential series solutions (transseries ... More
Singularity barriers and Borel plane analytic properties of 1+ difference equationsAug 12 2006The paper addresses generalized Borel summability of ``$1^+$'' difference equations in ``critical time''. We show that the Borel transform $Y$ of a prototypical such equation is analytic and exponentially bounded for $\Re(p)<1$ but there is no analytic ... More
What mediates the longest correlation length in the QCD plasma?Jan 17 2003When thermal QCD crosses the critical temperature from below, its pressure density rises drastically, consistent with the picture of deconfinement and the release of partons as light degrees of freedom. On the other hand, the concept of partons is a perturbative ... More
Approximations of the self-similar solution for blastwave in a medium with power-law density variationFeb 04 2000Approximations of the Sedov self-similar solution for a strong point explosion in a medium with the power-law density distribution \rho^o\propto r^{-m} are reviewed and their accuracy are analyzed. Taylor approximation is extended to cases m\neq 0. Two ... More
Determination of alpha_S at 500 GeV from Event Shapes and Jet RatesDec 22 1999The potential of the TESLA linear e+e- collider to determine the strong coupling constant, alpha_S, at 500 GeV is investigated. Experimental complications due to background from W- and Z-pairs, top-production, initial state photon radiation and from beamstrahlung ... More
Note on the magnetotransport in the normal state of high-Tc cupratesJun 02 2000Theories of the magnetotransport, based on the quasipartricle of the Fermi-liquid, in the normal state of high-Tc cuprate superconductors, are critically examined and the necessity of the collective transport theory beyond the quasiparticle is discussed. ... More
Note on the exponent puzzle of the Anderson-Mott transitionMar 30 2007The exponent puzzle of the Anderson-Mott transition is discussed on the basis of a duality model for strongly correlated electrons.
Note on the Spin-Spin Relaxation Time in High-Tc Cuprate SuperconductorsNov 16 2000Recent experiments on the spin-spin relaxation time in high-Tc cuprate superconductors are discussed on the basis of the BCS-RPA theory.
On the Quantum Inverse Problem for the Closed Toda ChainApr 07 2003We reconstruct the canonical operators $p_i,q_i$ of the quantum closed Toda chain in terms of Sklyanin's separated variables.
Upper functions for $L_p$-norm of gaussian random fieldsNov 20 2013In this paper we are interested in finding upper functions for a collection of random variables $\big\{\big\|\xi_{\vec{h}}\big\|_p, \vec{h}\in\mathrm{H}\big\}, 1\leq p<\infty$. Here $\xi_{\vec{h}}(x), x\in(-b,b)^d, d\geq 1$ is a kernel-type gaussian random ... More
Systematic effects in apparent proper motion of radio sourcesMay 08 2008The galactocentric rotation of the Solar system generates the systematic effect in proper motions known as 'secular aberration drift'. This tiny effect (about five microseconds per year) in the quasar proper motion can be measured by VLBI. However, the ... More
Analytic Form Factors of Hydrogenlike Atoms for Discrete-Continuum Transitions. II. General CaseJan 07 2002Mar 05 2003A general formula for bound-continuous transition form factors is derived. It is shown that these form factors can be represented in the form of finite sum of terms with simple analytical structure.
Modeling and optimization of the antenna system with focal plane array for the new generation radio telescopes with wide field of viewFeb 15 2016The model of the reflector antenna system with focal plane array, low-noise amplifier and beamformer is developed in the work. The beamformer strategy is suggested to reduce the receiving sensitivity ripple inside field of view of the telescope, while ... More
Higher-order corrections to the splitting functions from differential equations in QCDJan 14 2016We report on the status an ab initio computation of the time-like splitting functions at next-to-next-to-leading order in QCD. Time-like splitting functions govern the collinear kinematics of inclusive hadron production in $e^+e^-$ annihilation and the ... More
The Thom Class and Localization of SUSY QM Generating FunctionalNov 13 2001We demonstrate the usage of explicit form of the Thom class found by Mathai and Quillen for the definition of generating functional of a simple supersymmetric quantum mechanical model.
A New Basis Function Approach to 't Hooft EquationMar 13 2000We present the new basis functions to investigate the 't Hooft equation, the lowest order mesonic Light-Front Tamm-Dancoff equation for $\rm SU(N_C)$ gauge theories. We find the wave function can be well approximated by new basis functions and obtain ... More
Scientometric analysis of Condensed Matter Physics journalJun 26 2018The paper is dedicated to 25th anniversary of Condensed Matter Physics journal (CMP). It contains the results of comprehensive analysis of different journal-related data. CMP co-authorship relationships are studied analysing the collaboration network. ... More
On ultrametric-preserving functionsFeb 23 2019Several new characterizations of pseudoultrametric spaces and ultrametric spaces are found. In particular, a dual form of Pongsriiam-Termwuttipong characterization of the ultrametric-preserving functions is described.
Limit Theorem for Sums of Random ProductsOct 11 2002We study a generalization of the Random Energy Model to the case when the number of exponential factors varies at random. Also a relation between REM and the Erd"os-R'enyi limit theorem for maximums of partial sums is considered.
The combinatorial geometry of stresses in frameworksDec 08 2015In this paper we formulate and prove necessary and sufficient geometric conditions for existence of generic tensegrities in the plane for arbitrary graphs. The conditions are written in terms of "meet-join" relations for the configuration spaces of fixed ... More
Finite Ultrametric BallsOct 07 2018Mar 23 2019The necessary and sufficient conditions under which a given family $\mathcal{F}$ of subsets of finite set $X$ coincides with the family $\mathbf{B}_X$ of all balls generated by some ultrametric $d$ on $X$ are found. It is shown that the representing tree ... More
Hydrodynamic stability of rotationally supported flows: Linear and nonlinear 2D shearing box resultsApr 01 2004Aug 31 2004We present here both analytical and numerical results of hydrodynamic stability investigations of rotationally supported circumstellar flows using the shearing box formalism. Asymptotic scaling arguments justifying the shearing box approximation are systematically ... More
Magnetic fields in A stars besides Ap starsSep 24 2013I review ongoing efforts to understand the incidence of magnetism in intermediate-mass stars that are different from the magnetic Ap stars. This includes the search for magnetic fields in chemically peculiar stars of the Am and HgMn types as well as in ... More
The Paschen-Back effect in the Li I 6708 A line and the presence of lithium in cool magnetic Ap starsFeb 19 2008A number of cool magnetic Ap stars show a prominent feature at lambda 6708 A. Its identification with Li I remains controversial due to a poor knowledge of the spectra of rare-earth elements that are strongly enhanced in peculiar stars and can potentially ... More
Zeeman split lines in CP stars: a discovery of low-contrast fields in slow rotators?Nov 30 2007We show that high-resolution observations of resolved Zeeman split lines can be used to obtain new constraints on the stellar magnetic field geometry. In particular, the contrast of the field strength distribution over the stellar surface can be deduced ... More
Automated Trading Systems: Developed and Emerging Capital MarketsMay 04 2005Automated trading systems on developed and emerging capital markets are studied in this paper. The standard for developed market is automated trading system with 40-days simple moving average. We tested it for the index SIX Industrial for 1000 and 730 ... More
Anisotropic Vortices in High-Temperature Superconductors and the Onset of Vortex-like Excitations above the Critical TemperatureApr 28 2005Recently we have found that a three-dimensional superconducting state with anisotropic vortices localized at the vortex-lattice points is a stable state in zero external magnetic field for the layered high temperature uperconductivity materials. There ... More
Topology and Behaviour of Agents: Capital MarketsDec 31 2004Jun 15 2005On a capital market the social group is formed from traders. Individual behaviour of agents is influenced by the need to associate with other agents and to obtain the approval of other agents in the group. Making decisions an individual equates own needs ... More
Multiple time scales from hard local constraints: glassiness without disorderJul 13 2014Aug 18 2014While multiple time scales generally arise in the dynamics of disordered systems, we find multiple time scales in absence of disorder, in a simple model with hard local constraints. The dynamics of the model, which consists of local collective rearrangements ... More
LensClean revisitedDec 10 2003We discuss the LensClean algorithm which for a given gravitational lens model fits a source brightness distribution to interferometric radio data in a similar way as standard Clean does in the unlensed case. The lens model parameters can then be varied ... More
Magnetobreakdown oscillations of Nernst-Ettingshausen field in layered conductorsSep 15 2016In the presented report, the Nernst-Ettingshausen effect in layered conductors is investigated. Considering a Fermi surface (FS) consisting of a slightly corrugated cylinder and two corrugated planes distributed periodically in the momentum space, the ... More
Thermal X-ray emission of the remnants of ashperical Supernova explosionsMar 26 2001Evolution of adiabatic remnants of an aspherical supernova explosion in uniform medium are considered. Thermal X-ray emission of such remnants are investigated. It is shown that integral thermal X-ray characteristics (X-ray luminosity and spectrum) of ... More
Thermal X-ray composites as an effect of projectionJun 12 2000Mar 21 2001A new possibility to explain the nature of thermal X-ray composites (TXCs), i.e. a class of supernova remnants (SNRs) with a thermal X-ray centrally-filled morphology within a radio shell, as a projection effect of the 2- or 3-dimensional shell-like SNR ... More
On the transition of the adiabatic supernova remnant to the radiative stage in a nonuniform interstellar mediumApr 04 2006Methods for estimation of different reference times which appear in the description of transition of a strong adiabatic shock into the radiative era are reviewed. The need for consideration of an additional transition subphase in between the end of the ... More
A New Model for the Thermal X-ray Composites and the Neutral Pion Decay Gamma-Rays from Supernova RemnantsMar 23 2001May 08 2001Recent nonthermal X-ray and gamma-ray observations, attributed to electron emission processes, for the first time give an experimental confirmation that electrons are accelerated on SNR shocks up to the energy 10^{14} eV. We have no direct observational ... More
Evolution of supernova remnants in the interstellar medium with a large-scale density gradient. II. The 2-D modelling of the evolution and X-ray emission of supernova remnant RCW86Jan 25 1999The results of the 2D modelling of Supernova remnant (SNR) RCW86 are given. Models of this remnant, which for the first time interpret the anisotropy of surface brightness as a result of the evolution of adiabatic SNR in the interstellar medium with a ... More
Equations in dual variables for Whittaker functionsJul 18 2003It is known that the Whittaker functions $w(q,\lambda)$ associated to the group SL(N) are eigenfunctions of the Hamiltonians of the open Toda chain, hence satisfy a set of differential equations in the Toda variables $q_i$. Using the expression of the ... More
Event Shapes and Power Corrections in e+e- AnnihilationJun 15 2000The effects of the hadronisation of partons on the distribution of event shape observables are associated with corrections which are suppressed by reciprocal powers of the energy scale of the process. The correction is determined by one non-calculable ... More
alpha_S Evolution from 35 GeV to 202 GeV and Flavour IndependenceMay 26 2000Determinations of the strong coupling constant alpha_S at centre-of-mass energies of 192 through 202 GeV at LEP are presented. The energy evolution of alpha_S is in agreement with the prediction of QCD. The combined investigation of OPAL and JADE data ... More
Metallic Spin Glass in Infinite DimensionsMar 28 2000We have combined the dynamical mean field theories of the Mott transition and the spin glass in infinite dimensions and derived a metallic spin-glass state from a random spin-fermion model.
Density Matrix Kinetic Equation Describing a Passage of Fast Atomic Systems Through MatterMar 05 2003The quantum-mechanical consideration of a passage of fast dimesoatoms through matter is given. A set of quantum-kinetic equations for the density matrix elements describing their internal state evolution is derived. It is shown that probabilistic description ... More
Multi-beaming propertieis of reflector antennas used in radio telescopes with wide field of viewFeb 15 2016The given work is devoted to the modern developments in the field of radio astronomy instrumentation. In particular, the sensitivity of the multi-beam reflector radio telescope which is fed by phased array (PAF) is considered. Using PAF as reflector feed ... More
Influence of the interplay between de Gennes boundary conditions and cubicity of Ginzburg-Landau equation on the properties of superconducting filmsFeb 10 2012Exact solutions of the Ginzburg-Landau (GL) equation for the straight film subjected at its edges to the Robin-type boundary conditions characterized by the extrapolation length $\Lambda$ are analyzed with the primary emphasis on the interaction between ... More
Toward the unification of the postulates of Quantum MechanicsJan 18 2008In this paper we are going to introduce a new dynamical postulate in Quantum Mechanics. This new principle is defined using path integrals over the set of normalized wave functions. We will show in a qualitative way that this postulate is equivalent to ... More
Classical Solutions of SU(3) Yang-Mills Theory and Heavy Quark PhenomenologyNov 18 2004It is showed that potentials derived from classical solutions of the SU(3) Yang-Mills theory can provide confining potentials that reproduce the heavy quarkonium spectrum within the same level of precision as the Cornell potential.
On SU(2) Yang-Mills Theory and the Maximal Abelian GaugeMay 22 2001The problem of identifying the dynamical degrees of freedom for SU(2) gauge theories is discussed. After studying SU(N) theories, it is shown that classical pure SU(2) gauge theory is equivalent to an abelian theory. Finally, we prove that the Maximal ... More
Flavoured leptogenesis: a successful thermal leptogenesis with N_1 mass below 10^8 GeVDec 13 2005Jan 19 2006We prove that taking correctly into account the lepton flavour dependence of the CP asymmetries and washout processes, it is possible to obtain successful thermal leptogenesis from the decays of the second right-handed neutrino. The asymmetries in the ... More
Magnetic Coupling in the Quiet Solar AtmosphereApr 13 2009Three kinds of magnetic couplings in the quiet solar atmosphere are highlighted and discussed, all fundamentally connected to the Lorentz force. First the coupling of the convecting and overshooting fluid in the surface layers of the Sun with the magnetic ... More
A Monte-Carlo study of meandersJun 22 1999Oct 06 1999We study the statistics of meanders, i.e. configurations of a road crossing a river through "n" bridges, and possibly winding around the source, as a toy model for compact folding of polymers. We introduce a Monte-Carlo method which allows us to simulate ... More
Doppler imaging of chemical spots on magnetic Ap/Bp stars. Numerical tests and assessment of systematic errorsNov 16 2016Doppler imaging (DI) is a powerful spectroscopic inversion technique that enables conversion of a line profile time series into a two-dimensional map of the stellar surface inhomogeneities. In this paper we investigate the accuracy of chemical abundance ... More
Finite Ultrametric BallsOct 07 2018The necessary and sufficient conditions under which a given family $\mathcal{F}$ of subsets of finite set $X$ coincides with the family $\mathbf B_X$ of all balls generated by some ultrametric $d$ on $X$ are found. It is shown that the representing tree ... More
Corrections to the higher moments of the heavy ion energy-loss distribution beyond the Born approximation. II. Beta dependence of Mott's correctionsOct 01 2018Dec 18 2018The Mott corrections to the higher moments of the heavy ion energy-loss distribution are calculated in a wide range of relative particle velocity on the basis of the Mott exact cross section. It is shown that the relative Mott corrections to the first-order ... More
Effects of the Number of Active Receiver Channels on the Sensitivity of a Reflector Antenna System with a Multi-Beam Wideband Phased Array FeedFeb 15 2016A method for accurate modeling of a reflector antenna system with a wideband phased array feed is presented and used to study the effects of the number of active antenna elements and associated receiving channels on the receiving sensitivity of the antenna ... More
L2-Homogenization of Heat Equations on Tubular NeighborhoodsOct 28 2008We consider the heat equation with Dirichlet boundary conditions on the tubular neighborhood of a closed Riemannian submanifold. We show that, as the tube radius decreases, the semigroup of a suitably rescaled and renormalized generator can be effectively ... More
Constructing multidimensional periodic continued fractions in the sense of KleinNov 01 2004Dec 16 2008We consider the geometric generalization of ordinary continued fraction to the multidimensional case introduced by F. Klein in 1895. A multidimensional periodic continued fraction is the union of sails with some special group acting freely on these sails. ... More
Varieties With Ample Cotangent BundleJun 03 2003Sep 07 2011We study smooth projective complex varieties with ample cotangent bundle. Our main result is that in an abelian variety of dimension n, a complete intersection of at least n/2 general hypersurfaces of sufficiently high degrees has ample cotangent bundle. ... More
Oeljeklaus-Toma manifolds and arithmetic invariantsMar 07 2015Oeljeklaus-Toma (OT) manifolds are certain compact complex manifolds built from number fields. Conversely, we show that the fundamental group often pins down the number field uniquely. We relate the first homology to some interesting ideal. OT manifolds ... More
Edge-connectivity in regular multigraphs from eigenvaluesSep 22 2014Let $G$ be a $d$-regular multigraph, and let $\lambda_2(G)$ be the second largest eigenvalue of $G$. In this paper, we prove that if $\lambda_2(G) < \frac{d-1+\sqrt{9d^2-10d+17}}4$, then $G$ is 2-edge-connected. Furthermore, for $t\ge2$ we show that $G$ ... More
A new test for stick-slip limit cycles in dry-friction oscillators with small nonlinear friction characteristicsMay 17 2016We consider a dry friction oscillator on a moving belt with both the Coulomb friction and a small nonlinear addition which can model e.g. the Stribeck effect. By using the perturbation theory, we establish a new sufficient condition for the nonlinearity ... More
Tangent spaces to metric spaces and to their subspacesApr 28 2009We investigate a tangent space at a point of a general metric space and metric space valued derivatives. The conditions under which two different subspace of a metric space have isometric tangent spaces in a common point of these subspaces are completely ... More
Challenges to the Generalized Chaplygin Gas CosmologyMar 12 2004The generalized Chaplygin gas (GCG) model allows for an unified description of the cosmologically recent accelerated expansion of the Universe and of the evolution of energy density perturbations. This dark energy - dark matter unification is achieved ... More
Unparticle Searches Through Gamma Gamma ScatteringDec 22 2007Mar 10 2008We investigate the effects of unparticles on gamma gamma--> gamma gamma scattering for photon collider mode of the future multi-TeV e^+e^- linear collider. We show the effects of unparticles on the differential, and total scattering cross sections for ... More
Searching Unparticle Signatures Through Tau Pair ProductionJun 15 2009In this work, we study the possible unparticle signatures through tau pair production e+e- -> tau+tau- process at the low energy particle factories. We take into account lepton flavor conserving (s-channel) and violating (t-channel) couplings for the ... More
Quantum Cosmology for a Quadratic Theory of GravityNov 29 1994For pure fourth order (${\cal{L}} \propto R^2$) quantum cosmology the Wheeler-DeWitt equation is solved exactly for the closed homogeneous and isotropic model. It is shown that by imposing as boundary condition that $\Psi = 0$ at the origin of the universe ... More
CP Violation in Production and Decay of Supersymmetric ParticlesApr 20 2005In this thesis we analyze CP violating effects of MSSM phases in production and two-body decays of neutralinos, charginos and sfermions. For different supersymmetric processes we define and calculate CP-odd asymmetries, which base on triple products. ... More
Gamma-ray bursts, axion emission and string theory dilatonJan 14 1999The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has ... More
Pulsation in the atmosphere of roAp starsOct 08 2008High time resolution spectroscopy of roAp stars at large telescopes has led to a major breakthrough in our understanding of magnetoacoustic pulsations in these interesting objects. New observations have allowed to uncover a number of intricate relations ... More