Results for "O. Alexandrova"

total 35943took 0.13s
Structure of the Short Range Amplitude for General Scattering RelationsNov 26 2004We consider scattering by short range perturbations of the semi-classical Laplacian. We prove that when a polynomial bound on the resolvent holds, the scattering amplitude is a semi-classical Fourier integral operator associated to the scattering relation. ... More
Small Scale Energy Cascade of the Solar Wind TurbulenceOct 03 2007Magnetic fluctuations in the solar wind are distributed according to Kolmogorov's power law $f^{-5/3}$ below the ion cyclotron frequency $f_{ci}$. Above this frequency, the observed steeper power law is usually interpreted in two different ways: a dissipative ... More
Fluid-like dissipation of magnetic turbulence at electron scales in the solar windNov 23 2011The turbulent spectrum of magnetic fluctuations in the solar wind displays a spectral break at ion characteristic scales. At electron scales the spectral shape is not yet completely established. Here, we perform a statistical study of 102 spectra at plasma ... More
Semi-Classical Wavefront Set and Fourier Integral OperatorsJul 27 2004We define and prove some properties of the semi-classical wavefront set. We also define and study semi-classical Fourier integral operators, of which we give a complete characterization. Lastly, we prove a generalization of the semi-classical Egorov's ... More
Semi-Classical Behavior of the Spectral FunctionFeb 26 2005We study the semi-classical behavior of the spectral function of the Schr\"{o}dinger operator with short range potential. We prove that the spectral function is a semi-classical Fourier integral operator quantizing the forward and backward flow relations ... More
Structure of the Semi-Classical Amplitude for General Scattering RelationsJul 28 2004We consider scattering by general compactly supported semi-classical perturbations of the Euclidean Laplace-Beltrami operator. We show that if the suitably cut-off resolvent of the Hamiltonian quantizes a Lagrangian relation on the product cotangent bundle, ... More
Methods for characterising microphysical processes in plasmasJun 22 2013Advanced spectral and statistical data analysis techniques have greatly contributed to shaping our understanding of microphysical processes in plasmas. We review some of the main techniques that allow for characterising fluctuation phenomena in geospace ... More
Suprathermal electron strahl widths in the presence of narrow-band whistler waves in the solar windJan 17 2017We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind. We show that this interaction does occur and that it is associated with enhanced widths of the so ... More
Coherent structures at ion scales in fast solar wind: {\it Cluster} observationsSep 27 2017We investigate the nature of magnetic turbulent fluctuations, around ion characteristic scales, in a fast solar wind stream, by using {\it Cluster} data. Contrarily to slow solar wind, where both Alfv\'enic ($\delta b_{\perp} \gg \delta b_{\parallel}$) ... More
Compressive Coherent Structures at Ion Scales in the Slow Solar WindApr 26 2016We present a study of magnetic field fluctuations, in a slow solar wind stream, close to ion scales, where an increase of the level of magnetic compressibility is observed. Here, the nature of these compressive fluctuations is found to be characterized ... More
Anisotropy of Solar Wind Turbulence between Ion and Electron ScalesFeb 12 2010Jun 27 2010The anisotropy of turbulence in the fast solar wind, between the ion and electron gyroscales, is directly observed using a multispacecraft analysis technique. Second order structure functions are calculated at different angles to the local magnetic field, ... More
Solar wind turbulent spectrum from MHD to electron scalesDec 14 2009Turbulent spectra of magnetic fluctuations in the free solar wind are studied from MHD to electron scales using Cluster observations. We discuss the problem of the instrumental noise and its influence on the measurements at the electron scales. We confirm ... More
Resolvent and scattering matrix at the maximum of the potentialNov 06 2007We study the microlocal structure of the resolvent of the semi-classical Schrodinger operator with short range potential at an energy which is a unique non-degenerate global maximum of the potential. We prove that it is a semi-classical Fourier integral ... More
Dynamical Bonding Driving Mixed Valency in a Metal BorideMar 26 2019Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed-valent semiconductor, and later - a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. ... More
A local approach to the study of energy transfers in incompressible magnetohydrodynamic turbulenceDec 14 2018We present a local approach to the study of scale-to-scale energy transfers in magnetohydrodynamic (MHD) turbulence. This approach is based on performing local averages of the physical fields, which amounts to filtering scales smaller than some parameter ... More
Semiclassical scattering amplitude at the maximum point of the potentialApr 12 2007Apr 13 2007We compute the scattering amplitude for Schr\"odinger operators at a critical energy level, corresponding to the maximum point of the potential. We follow the wrok of Robert and Tamura, '89, using Isozaki and Kitada's representation formula for the scattering ... More
Simplices with equiareal facesSep 10 2009We study simplices with equiareal faces in the Euclidean 3-space by means of elementary geometry. We present an unexpectedly simple proof of the fact that, if such a simplex is non-degenerate, than every two of its faces are congruent. We show also that ... More
Spectra and anisotropy of magnetic fluctuations in the Earth's magnetosheath: Cluster observationsOct 03 2008We investigate the spectral shape, the anisotropy of the wave vector distributions and the anisotropy of the amplitudes of the magnetic fluctuations in the Earth's magnetosheath within a broad range of frequencies. We present the first observations of ... More
Coherent events and spectral shape at ion kinetic scales in the fast solar wind turbulenceFeb 23 2016In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements of the Wind spacecraft in a fast ... More
A local approach to the study of energy transfers in incompressible magnetohydrodynamic turbulenceDec 14 2018Apr 16 2019We present a local approach to the study of scale-to-scale energy transfers in magnetohydrodynamic (MHD) turbulence. This approach is based on performing local averages of the physical fields, which amounts to filtering scales smaller than some parameter ... More
Anisotropies of the magnetic field fluctuations at kinetic scales in the solar wind : Cluster observationsOct 06 2017We present the first statistical study of the anisotropy of the magnetic field turbulence in the solar wind between 1 and 200Hz, i.e. from proton to sub-electron scales. We consider 93 10-minute intervals of Cluster/STAFF measurements. We find that the ... More
Magnetospheric Multiscale Observation of Kinetic Signatures in the Alfvén VortexJan 12 2019Alfv\'en vortex is a multi-scale nonlinear structure which contributes to intermittency of turbulence. Despite previous explorations mostly on the spatial properties of the Alfv\'en vortex (i.e., scale, orientation, and motion), the plasma characteristics ... More
Solar wind turbulent spectrum at plasma kinetic scalesDec 03 2012The description of the turbulent spectrum of magnetic fluctuations in the solar wind in the kinetic range of scales is not yet completely established. Here, we perform a statistical study of 100 spectra measured by the STAFF instrument on the Cluster ... More
[Plasma 2020 Decadal] Multipoint Measurements of the Solar Wind: A Proposed Advance for Studying Magnetized TurbulenceMar 13 2019A multi-institutional, multi-national science team will soon submit a NASA proposal to build a constellation of spacecraft to fly into the near-Earth solar wind in a swarm spanning a multitude of scales in order to obtain critically needed measurements ... More
Gyrokinetic theory of magnetic structures in high-beta plasmas of the Earths magnetopause and of the slow solar windMay 08 2017Nonlinear effects of the trapping of resonant particles by the combined action of the electric field and the magnetic mirror force is studied using a gyrokinetic description that includes the finite Larmor radius effects. A general nonlinear solution ... More
Fluid theory of coherent magnetic vortices in high-beta space plasmasMay 08 2017Jun 11 2018In-situ observations in the Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfv\'en vortices as intermittent structures in the range of scales from tens to several ion scales. These magnetic vortices appear compressible ... More
Observation of an MHD Alfvén vortex in the slow solar windFeb 24 2016In the solar wind, magnetic field power spectra usually show several power-laws. In this paper, magnetic field data from the Cluster mission during an undisturbed interval of slow solar wind is analyzed at 0.28Hz, near the spectral break point between ... More
Photo-driven Molecular Wankel Engine B$_{13}^+$Apr 11 2012We report a molecular Wankel motor, the dual-ring structure B13+, driven by circularly-polarized infrared electromagnetic radiation, under which a guided uni-directional rotation of the outer ring is achieved with rotational frequency of the order of ... More
3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?Feb 27 2018Jan 30 2019We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method ... More
[Plasma 2020 Decadal] Disentangling the Spatiotemporal Structure of Turbulence Using Multi-Spacecraft DataMar 13 2019This white paper submitted for 2020 Decadal Assessment of Plasma Science concerns the importance of multi-spacecraft missions to address fundamental questions concerning plasma turbulence. Plasma turbulence is ubiquitous in the universe, and it is responsible ... More
Assembling Di- and Multiatomic Si Clusters in Graphene via Electron Beam ManipulationOct 25 2017May 22 2018We demonstrate assembly of di-, tri- and tetrameric Si clusters on the graphene surface using sub-atomically focused electron beam of a scanning transmission electron microscope. Here, an electron beam is used to introduce Si substitutional defects and ... More
Universality of solar wind turbulent spectrum from MHD to electron scalesJun 17 2009Sep 01 2009In order to investigate the universality of magnetic turbulence in space plasmas we analyze seven time periods in the free solar wind of different origin, slow or fast, and under different plasma conditions. The orientation of magnetic field to the flow ... More
Solar Wind Turbulence and the Role of Ion InstabilitiesJun 22 2013Solar wind is probably the best laboratory to study turbulence in astrophysical plasmas. In addition to the presence of magnetic field, the differences with neutral fluid isotropic turbulence are: weakness of collisional dissipation and presence of several ... More
Variability Of The Magnetic Field Power Spectrum In The Solar Wind At Electron ScalesOct 13 2017At the electron scales the power spectrum of solar-wind magnetic fluctuations can be highly variable and the dissipation mechanisms of the magnetic energy into the various particle species is under debate. In this paper we investigate data from the Cluster ... 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
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.
Three-dimensional local anisotropy of velocity fluctuations in the solar windApr 08 2019We analyse velocity fluctuations in the solar wind at magneto-fluid scales in two datasets, extracted from Wind data in the period 2005-2015, that are characterised by strong or weak expansion. Expansion affects measurements of anisotropy because it breaks ... More
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
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
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 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
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
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
Study of ultra-high gradient acceleration in carbon nanotube arraysMay 03 2018Solid-state based wakefield acceleration of charged particles was previously proposed to obtain extremely high gradients on the order of 1-10 TeV/m. In recent years the possibility of using either metallic or carbon nanotube structures is attracting new ... 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
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
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
Two-photon exchange corrections in elastic electron-proton scatteringJan 29 2016We apply a subtracted dispersion relation (DR) formalism with the aim to improve predictions for the two-photon exchange (TPE) corrections to elastic electron-proton scattering observables at small momentum transfers. We study the formalism on the elastic ... More
Guiding structures with multiply connected cross-sections: evolution of propagation in external fields at complex Robin parametersJul 05 2011Properties of the two-dimensional ring and three-dimensional infinitely long straight hollow waveguide with unit width and inner radius $\rho_0$ in the superposition of the longitudinal uniform magnetic field $\bf B$ and Aharonov-Bohm flux are analyzed ... More
Comparative analysis of electric field influence on the quantum wells with different boundary conditions. II. Thermodynamic propertiesFeb 10 2015Apr 07 2015Thermodynamic properties of the one-dimensional (1D) quantum well (QW) with miscellaneous permutations of the Dirichlet (D) and Neumann (N) boundary conditions (BCs) at its edges in the perpendicular to the surfaces electric field $\mathscr{E}$ are calculated. ... More
Superparamagnetic nanoparticle ensemblesNov 20 2009Aug 08 2012Magnetic single-domain nanoparticles constitute an important model system in magnetism. In particular ensembles of superparamagnetic nanoparticles can exhibit a rich variety of different behaviors depending on the inter-particle interactions. Starting ... More
Development of Wearable Systems for Ubiquitous Healthcare Service ProvisioningApr 01 2014This paper reports on the development of a wearable system using wireless biomedical sensors for ubiquitous healthcare service provisioning. The prototype system is developed to address current healthcare challenges such as increasing cost of services, ... More
Minimum weight spanning trees of weighted scale free networksSep 20 2012In this lecture we will consider the minimum weight spanning tree (MST) problem, i.e., one of the simplest and most vital combinatorial optimization problems. We will discuss a particular greedy algorithm that allows to compute a MST for undirected weighted ... More
Encryption dynamics and avalanche parameter for "delayed dynamics"-based cryptosystemsJan 30 2012The presented article attempts to characterize the encryption dynamics of delayed dynamics based block ciphers, designed for the encryption of binary data. For such encryption algorithms, the encryption process relies on a coupling dynamics with time ... More
The local stellar velocity distribution of the Galaxy. Galactic structure and potentialOct 06 1998The velocity distribution of neighbouring stars is deduced from the Hipparcos proper motions. We have used a classical Schwarzschild decomposition and also developed a dynamical model for quasi-exponential stellar discs. This model is a 3-D derivation ... 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