Results for "V. V. Ryzhikov"

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On spectral multiplicities of Gaussian actionsJun 12 2014Jun 30 2014For any set $M$ of natural numbers there are mixing Gaussian automorphisms and non-mixing Gaussian automorphisms with singular spectrum (as well as some automorphisms which are disjoint from all Gaussian actions) such that $ M\cup\{\infty\}$ is the set ... More
Homogeneous spectrum, Disjointness of Convolutions, and Mixing Properties of Dynamical SystemsJun 26 2012Jun 27 2012In connection with Rokhlin's question on an automorphism with a homogeneous nonsimple spectrum, we indicate a class of measure-preserving maps $T$ such that $T\times T$ has a homogeneous spectrum of multiplicity 2. The automorphisms in question satisfy ... More
Lebesgue Component in Spectrum for Tensor Product of Generic MultipliesJan 16 2013Jan 18 2013Generic (rigid) measure-preserving transformations with Lebesgue component in spectrum of their tensor product, two rigid Gaussian systems and two rigid Poisson suspensions with similar spectral interactions are presented.
On Disjointness of Mixing Rank One ActionsSep 04 2011For flows the rank is an invariant by linear change of time. But what we can say about isomorphisms? It seems that in case of mixing flows this problem is the most difficult. However the known technique of joinings provides non-isomorphism for mixing ... More
On Local Rank, Joinings and Asymptotic Properties of Measure-Preserving ActionsMay 31 2012The note contains a collection of facts and observations around locally rank one actions as well as constructions connected with some results by T.Downarowicz, A.Katok, J.King, F.Parreau, A.A.Prikhodko, E.Roy, J.Serafin, J-P.Thouvenot et al.
On Mixing Constructions with Algebraic SpacersAug 06 2011Aug 09 2011We recall a proof of the mixing for almost all Ornstein's stochastic rank one constructions, replace stochastic spacers by special algebraic ones and prove the mixing in this new situation.
Simple Spectrum for Tensor Products of Mixing Map PowersJul 24 2011We prove the existence of a mixing rank one map $T$ such that the product $T\otimes T^2\otimes T^3\otimes...$ has simple spectrum. This result is used in S.V. Thikhonov's proof of the existence of mixing transformation with homogeneous spectrum of multiplicity ... More
Spectral multiplicity for powers of weakly mixing automorphismsFeb 15 2011We study the behavior of maximal multiplicities $mm (R^n)$ for the powers of a weakly mixing automorphism $R$. For some special infinite set $A$ we show the existence of a weakly mixing rank-one automorphism $R$ such that $mm (R^n)=n$ and $mm(R^{n+1}) ... More
Asymmetries in Asymptotic 3-fold Properties of Ergodic ActionsFeb 04 2014Feb 10 2014We present: 1) a mixing $Z ^ 2$-action with the following asymmetry of multiple mixing property: for some commuting measure-preserving transformations $S$, $T$ and a sequence $n_j$ $$ \lim_{j\to \infty}\mu(A\bigcap S^{-n_j}A\bigcap T^{-n_j}A)=\mu(A)^3$$ ... More
On Mixing of Staircase TransformationsAug 17 2011We prove the mixing for all staircase transformations satisfied the conditions $r_j/h_j\to 0$ + $r_j\to\infty$.
Chacon's Type Ergodic Transformations with Unbounded Arithmetic SpacersNov 18 2013Dec 02 2013The following generalizations of the Chacon map are proposed: instead of classical constant spacer sequence $(0,1,0)$ let a sequence $(0,s_j,0)$ be one with unbounded $s_j$. (We mention also an analogue of the historical Chacon map with spacer sequences ... More
Ergodic bounded constructions, Disjointness and Weak Limits of PowersJan 08 2013Apr 25 2013In connection with some recent results by J. Bourgain and H. Abdalaoui, M. Lemanczyk, T. De La Rue (ALR) we present a short proof of Bourgain's theorem on Mobius orthogonality property for bounded rank-one constructions. The proof of the fact (due to ... More
On Mixing Rank One Infinite TransformationsJun 23 2011J.-P. Thouvenot and the author showed via different approaches that the centralizer of a mixing rank-one infinite measure preserving transformation was trivial. In this note the author presents his joining proof. We also consider constructions with algebraic ... More
On Thouvenot's ergodic proof of Roth's theoremJul 27 2011Aug 02 2011We present a lecture note on Thouvenot's proof of the Roth-Furstenberg theorem and joining proofs of Furstenberg's theorems on multiple progression average mixing for weakly mixing transformations.
Minimal Self-Joinings, Bounded Constructions, and Weak Closure of Ergodic ActionsDec 11 2012Dec 12 2012For a weakly mixing bounded rank-one construction the disjointness of its powers is proved. For non-rigid constructions we get minimal self-joinings. Examples of non-mixing rank one actions with explicit weak closure are proposed.
Weakly homoclinic groups of ergodic actionsJan 25 2019This work contains the following results: the trajectory fullness of the homoclinic groups, their connections with factors, K-property, weak multiple mixing; the ergodicity of the weakly homoclinic group for Gauss and Poisson actions; the triviality of ... More
Spectral properties and approximations of joinings for infinite rank-one actionsFeb 08 2019An ergodic self-joining of an infinite rank-one transformation is a part of the weak limit of off-diagonal measures. A class of uncountaible cardinality of nonisomorphic transformations with polynomial weak closure is presented. Such actions have minimal ... More
Local Rank of Ergodic Symmetric $n$-Powers does not exceed $n!n^{-n}$Aug 29 2011We prove that local rank of an ergodic symmetric power $T^{\odot n}$ does not exceed $n!n^{-n}$. A. Katok's old results show that this upper bound is exact. We prove also that $T^{\odot n}$ has infinite Rank as $n>1$.
Weak Closure Theorem for Double Staircase ActionsAug 02 2011We introduce a double staircase construction $T$ and show that the weak closure of $\{T^n\}$ is $\{\int, 2^{-m}T^n+(1-2^{-m})\int \ : m\in\N,\ n\in \Z\}.$
On the isomorphism of tensor powers of ergodic flowsOct 31 2016Nov 28 2016The following question due to Thouvenot is well-known in ergodic theory. Let $S$ and $T$ be automorphisms of a probability space and let $ S \times S $ be isomorphic to $T \times T $. Could $S$ be not isomorphic to $T$? Our note contains a simple answer ... More
Homoclinic invariants of ergodic actionsNov 09 2016Nov 29 2016We consider a family of homoclinic groups and Gordin's type invariants of measure-preserving actions, state their connections with factors, full groups, ranks, rigidity, multiple mixing and realize such invariants in the class of Gaussian and Poisson ... More
On the isomorphism of tensor powers of ergodic flowsOct 31 2016The following question due to Thouvenot is well-known in ergodic theory. Let $S$ and $T$ be automorphisms of a probability space and let $ S \times S $ be isomorphic to $T \times T $. Could $S$ be not isomorphic to $T$? Our note contains a simple answer ... More
Homoclinic invariants of ergodic actionsNov 09 2016We consider a family of homoclinic groups and Gordin's type invariants of measure-preserving actions, state their connections with factors, full groups, ranks, rigidity, multiple mixing and realize such invariants in the class of Gaussian and Poisson ... More
On the isomorphism of tensor powers of ergodic flowsOct 31 2016Dec 19 2016The following question due to Thouvenot is well-known in ergodic theory. Let $S$ and $T$ be automorphisms of a probability space and let $ S \otimes S $ be isomorphic to $T \otimes T $. Could $S$ be not isomorphic to $T$? Our note contains a simple answer ... More
Mixing Flows with Homogeneous Spectrum of Multiplicity TwoApr 30 2014A mixing flow with homogeneous spectrum of multiplicity 2 is presented.
Energy Resolution Improvement of Scintielectron detectors: Priorities and ProspectsJan 25 2002The development prospects of a scintillator-photodiode type detector with an improved energy resolution attaining few per cent, R from 1 to 2%, are considered. The main resolution components have been analyzed theoretically, their theoretical and physical ... More
Multi-energy techniques for radiographic monitoring of chemical compositionJun 03 2002A theoretical model of multi-energy radiography (MER) are proposed. It is shown that, as distinct from the conventional radiography, MER allows identification of organic substances and control of their chemical composition. Broad prospects are noted for ... More
Several questions and hypotheses concerning the limit polynomials for Chacon transformationJul 03 2012We study the weak closure $L$ of powers $T^k$ of the non-singular Chacon transformation $T$ with 2-cuts. This is still an open question does $L$ contain any Markov operator except an orthogonal projector to the constants $\Theta$ and some polynomials ... More
On spectral multiplicities {2, 4,..., 2^n} for totally ergodic Z^2-actionsDec 20 2012For totally ergodic Z^2-actions a collection of weak limits provide the set {2,4, ..., 2 ^ n} of spectral multiplicities for their tensor product. Our conditions allow to obtain a similar result for mixing actions via some limit procedure.
Outlook for development of a scintielectron detector with improved energy resolutionFeb 22 2002Feb 25 2002The development prospects have been considered of a scintillator-photodiode type detector with improved energy resolution attaining several per cent ($R=1-2%$). The main contributions to the scintielectron detector energy resolution have been analyzed ... More
On self-similarities of ergodic flowsNov 01 2010Jan 04 2012Given an ergodic flow $T=(T_t)_{t\in\Bbb R}$, let $I(T)$ be the set of reals $s\ne 0$ for which the flows $(T_{st})_{t\in\Bbb R}$ and $T$ are isomorphic. It is proved that $I(T)$ is a Borel subset of $\Bbb R^*$. It carries a natural Polish group topology ... More
Spectral multiplicities for infinite measure preserving transformationsMay 21 2009Aug 28 2010Each subset $E\subset\Bbb N$ is realized as the set of essential values of the multiplicity function for the Koopman operator of an ergodic conservative infinite measure preserving transformation.
Mixing constructions with infinite invariant measure and spectral multiplicitiesAug 12 2009Jan 19 2010We introduce high staircase infinite measure preserving transformations and prove that they are mixing under a restricted growth condition. This is used to (i) realize each subset $E\subset\Bbb N\cup\{\infty\}$ as the set of essential values of the multiplicity ... More
The Complexity of Clausal Fragments of LTLJun 21 2013Oct 10 2013We introduce and investigate a number of fragments of propo- sitional temporal logic LTL over the flow of time (Z, <). The fragments are defined in terms of the available temporal operators and the structure of the clausal normal form of the temporal ... More
Direct reconstruction of the effective atomic number of materials by the method of multi-energy radiographyOct 23 2003A direct method is proposed for reconstruction of the effective atomic number by means of multi-energy radiography of the material. The accuracy of the method is up to 95% . Advantages over conventional radiographic methods, which ensure accuracy of just ... More
Photoconductivity of CdS-CdSe granular films: influence of microstructureOct 14 2008Aug 23 2010We study experimentally the photoconductivity of CdS-CdSe sintered granular films obtained by the screen printing method. We mostly focus on the dependences of photoconductivity on film's microstructure, which varies with changing heat-treatment conditions. ... More
Detection of organic materials by spectrometric radiography methodOct 03 2008In this paper we report a spectrometric approach to dual-energy digital radiography that has been developed and applied to identify specific organic substances and discern small differences in their effective atomic number. An experimental setup has been ... More
Multi-Energy Radiography Against Terrorism. Theory and ExperimentsApr 23 2005May 22 2006Multi-energy radiography is a new direction in non-destructive testing. Its specific feature is separate detection of penetrating radiation in several energy channels. Multi-energy radiography allows quantitative determination of the atomic composition ... More
X-ray multi-energy radiography with scintillator-photodiode detectorsJun 05 2002Nov 29 2002For reconstruction of the spatial structure of many-component objects, it is proposed to use multi-radiography with detection of X-ray by combined detector arrays using detectors of ``scintillator-photodiode'' type. A theoretical model has been developed ... More
Multi-energy radiography on the basis of "scintillator-photodiode" detectorsJun 10 2002Nov 29 2002For reconstruction of the spatial structure and thicknesses of complex objects and materials, it is proposed to use multi-radiography with detection of X-ray or gamma-radiation by combined detector arrays of scintillator-photodiode type. Experimental ... More
X-Ray Multi-Energy Introscopy Systems with New Semiconductor ScintillatorsJun 10 2002Theoretical background and data on the ways of practical realization are presented, related to the problem of detection of dangerous organic objects (explosives, drugs, etc.) in the presence of other organic substances with atomic number differing by ... More
The Complexity of Ontology-Based Data Access with OWL 2 QL and Bounded Treewidth QueriesFeb 11 2017Our concern is the overhead of answering OWL 2 QL ontology-mediated queries (OMQs) in ontology-based data access compared to evaluating their underlying tree-shaped and bounded treewidth conjunctive queries (CQs). We show that OMQs with bounded-depth ... More
Scintillator-photodiode type detectors for multi-energy scanning introscopyJul 23 2002Results of experimental studies of detector arrays S-PD (scintillator-photodiode) and PRD (scintillator-photoreceiving device) used for X-ray digital radiography have shown that there exist further possibilities to increase spatial resolution of this ... More
Sub-wavelength imaging: Resolution enhancement using metal wire gratingsSep 26 2005An experimental evidence of subwavelength imaging with a "lens", which is a uniaxial negative permittivity wire medium slab, is reported. The slab is formed by gratings of long thin parallel conducting cylinders. Taking into account the anisotropy and ... More
Quantum Engineering of Single-Crystalline Silver Thin FilmsJun 20 2018Nov 20 2018There is a demand for the manufacture of ultra low-loss metallic films with high-quality single crystals and surface for quantum optics and quantum information processing. Many researches are devoted to alternative materials, but silver is by far the ... More
Toward theoretically limited SPP propagation length above two hundred microns on ultra-smooth silver surfaceJun 20 2018Aug 28 2018We demonstrate the optical medium for surface plasmon - polariton waves (SPP) propagation with ultra low losses corresponding to the theoretically limited values. The unique element of the optical medium is an atomically-flat single-crystalline silver ... More
Synchronization Problems in Automata without Non-trivial CyclesFeb 27 2017Dec 06 2017We study the computational complexity of various problems related to synchronization of weakly acyclic automata, a subclass of widely studied aperiodic automata. We provide upper and lower bounds on the length of a shortest word synchronizing a weakly ... More
Application of PbWO4 crystal scintillators in experiment to search for double beta decay of 116CdDec 10 2004PbWO4 crystal scintillators are discussed as an active shield and light-guides in 116Cd double beta decay experiment with CdWO4 scintillators. Scintillation properties and radioactive contamination of PbWO4 scintillators were investigated. Energy resolution ... More
Ergodic Homoclinic Groups, Infinite Sidon Constructions and Poisson SuspensionsApr 01 20141. We answer Michael Gordin's question providing singular spectrum for transformations with homoclinic Bernoulli flows via Poisson suspensions induced by modified Sidon rank-one constructions. 2. We give homoclinic proof of Emmanuel Roy's theorem on multiple ... More
Approximating the Maximum Number of Synchronizing States in AutomataAug 02 2016Sep 18 2016We consider the problem {\sc Max Sync Set} of finding a maximum synchronizing set of states in a given automaton. We show that the decision version of this problem is PSPACE-complete and investigate the approximability of {\sc Max Sync Set} for binary ... More
Plasmonic nanolaser for intracavity spectroscopy and sensoricsSep 07 2017We demonstrate intracavity plasmonic laser spectroscopy using a plasmonic laser created from a periodically-perforated silver film with a liquid gain medium. An active zone of the laser is formed by a highly elongated spot of pumping. This results in ... More
Deterministic integration of single nitrogen-vacancy centers into nanopatch antennasFeb 15 2019Quantum emitters coupled to plasmonic nanoantennas produce single photons at unprecedentedly high rates in ambient conditions. This enhancement of quantum emitters' radiation rate is based on the existence of optical modes with highly sub-diffraction ... More
Modification of incoherent scattering under the influence of system eigenmodesAug 09 2018Jan 21 2019The optical properties of inhomogeneous cerium dioxide (CeO2) films on aluminum (Al) sublayer are investigated. The dependencies of the reflection, scattering, and absorption of coherent electromagnetic radiation as functions of the incidence angle and ... More
Finding Short Synchronizing Words for Prefix CodesJun 16 2018We study the problems of finding a shortest synchronizing word and its length for a given prefix code. This is done in two different settings: when the code is defined by an arbitrary decoder recognizing its star and when the code is defined by its literal ... More
Palindromic Subsequences in Finite WordsJan 22 2019In 1999 Lyngs{\o} and Pedersen proposed a conjecture stating that every binary circular word of length $n$ with equal number of zeros and ones has an antipalindromic linear subsequence of length at least $\frac{2}{3}n$. No progress over a trivial $\frac{1}{2}n$ ... More
On Minimum Maximal Distance-k MatchingsFeb 15 2016We study the computational complexity of several problems connected with the problems of finding a maximal distance-$k$ matching of minimum cardinality or minimum weight. We introduce the class of $k$-equimatchable graphs which is an edge analogue of ... More
Subset Synchronization in Monotonic AutomataMar 18 2017Nov 23 2017We study extremal and algorithmic questions of subset and careful synchronization in monotonic automata. We show that several synchronization problems that are hard in general automata can be solved in polynomial time in monotonic automata, even without ... More
Kolmogorov complexity in the USSR (1975--1982): isolation and its endJul 11 2019These reminiscences are about the "dark ages" of algorithmic information theory in the USSR. After a great interest in this topic in 1960s and the beginning of 1970s the number of people working in this area in the USSR decreased significantly. At that ... More
A remark on the Dixmier ConjectureNov 30 2018The Dixmier Conjecture says that every endomorphism of the (first) Weyl algebra $A_1$ (over a field of characteristic zero) is an automorphism, i.e., if $PQ-QP=1$ for some $P, Q \in A_1$ then $A_1 = K \langle P, Q \rangle$. The Weyl algebra $A_1$ is a ... More
Polaron spin echo envelope modulations in an organic semiconducting polymerSep 09 2016Theoretical treatment of the electron spin echo envelope modulation (ESEEM) spectra from polarons in a semiconducting $\pi$- conjugated polymer is presented. The contact hyperfine coupling and the dipolar interaction between the polaron and proton spins ... More
Decay of the rotary echoes for the spin of a nitrogen-vacancy center in diamondMar 25 2014We study dynamics of the electron spin of a nitrogen-vacancy (NV) center subjected to a strong driving field with periodically reversed direction (train of rotary echoes). We use analytical and numerical tools to analyze in detail the form and timescales ... More
Constructing the ultimate theory of grand unificationMay 16 2011Nov 02 2011In accordance with known phenomenological facts on leptons and quarks in the Standard Model as well as on the scale of neutrino masses and introducing the supersymmetry, we logically substantiate the unique composition of fundamental representation for ... More
Theory of the electron relaxation in metals excited by an ultrashort optical pumpAug 20 2013Mar 05 2014The theory of the electron relaxation in metals excited by an ultrashort optical pump is developed on the basis of the solution of the linearized kinetic equation. The kinetic equation includes both the electron-electron and the electron-phonon collision ... More
Data Complexity and Rewritability of Ontology-Mediated Queries in Metric Temporal Logic under the Event-Based Semantics (Full Version)May 30 2019Jul 01 2019We investigate the data complexity of answering queries mediated by metric temporal logic ontologies under the event-based semantics assuming that data instances are finite timed words timestamped with binary fractions. We identify classes of ontology-mediated ... More
Quantum dynamics of nuclear spins and spin relaxation in organic semiconductorsJul 06 2016We investigate the role of the nuclear spin quantum dynamics in hyperfine-induced spin relaxation of hopping carriers in organic semiconductors. The fast hopping regime with a small carrier spin precession during a waiting time between hops is typical ... More
Explicit description of generalized weight modules of the algebra of polynomial integro-differential operators $I_n$Jun 02 2019For the algebra $I_n$ of polynomial integro-differential operators over a field $K$ of characteristic zero, a classification of simple weight and generalized weight (left and right) $I_n$-modules is given. It is proven that the category of weight $I_n$-modules ... More
Two-dimensional model of intrinsic magnetic flux losses in helical flux compression generatorsSep 25 2012Helical Flux Compression Generators (HFCG) are used for generation of mega-amper current and high magnetic fields. We propose the two dimensional HFCG filament model based on the new description of the stator and armature contact point. The model developed ... More
Realistic model of correlated disorder and Anderson localizationApr 01 1999A conducting 1D chain or 2D film inside (or on the surface of) an insulator is considered. Impurities displace the charges inside the insulator. This results in a long-range fluctuating electric field acting on the conducting line (plane). This field ... More
Morita invariance of the filter dimension and of the inequality of BernsteinOct 29 2006It is proved that the filter dimenion is Morita invariant. A direct consequence of this fact is the Morita invariance of the inequality of Bernstein: if an algebra $A$ is Morita equivalent to the ring $\CD (X)$ of differential operators on a smooth irreducible ... More
Hyperfine-induced spin relaxation of a diffusively moving carrier in low dimensions: implications for spin transport in organic semiconductorsMar 27 2015The hyperfine coupling between the spin of a charge carrier and the nuclear spin bath is a predominant channel for the carrier spin relaxation in many organic semiconductors. We theoretically investigate the hyperfine-induced spin relaxation of a carrier ... More
Double resonant processes in $χ^{(2)}$ nonlinear periodic mediaAug 07 2000In a one-dimensional periodic nonlinear $\chi^{(2)}$ medium, by choosing a proper material and geometrical parameters of the structure, it is possible to obtain two matching conditions for simultaneous generation of second and third harmonics. This leads ... More
Neutron Diffraction and Optics of a Noncentrosymmetric Crystal. New Feasibility of a Search for Neutron EDMApr 25 2005May 03 2005Recently strong electric fields (up to 10^9 V/cm) have been discovered, which affect the neutrons moving in noncentrosymmetric crystals. Such fields allow new polarization phenomena in neutron diffraction and optics and provide, for instance, a new feasibility ... More
Data Complexity and Rewritability of Ontology-Mediated Queries in Metric Temporal Logic under the Event-Based Semantics (Full Version)May 30 2019We investigate the data complexity of answering queries mediated by metric temporal logic ontologies under the event-based semantics assuming that data instances are finite timed words timestamped with binary fractions. We identify classes of ontology-mediated ... More
Linearly ordered compacts and co-Namioka spacesJan 25 2016It is shown that for any Baire space $X$, linearly ordered compact $Y$ and separately continuous mapping $f:X\times Y\to\mathbb R$ there exists a dense in $X$ $G_\delta$-set $A\subseteq X$ such that $f$ is jointly continuous at every point of $A\times ... More
Metrizable compacta in the space of continuous functions with the topology of pointwise convergenceDec 23 2015We prove that every point-finite family of nonempty functionally open sets in a topological space $X$ has the cardinality at most an infinite cardinal $\kappa$ if and only if $w(X)\leq\kappa$ for every Valdivia compact space $Y\subseteq C_p(X)$. Correspondingly ... More
The Gould BeltJul 23 2015This review is devoted to studies of the Gould belt and the Local system. Since the Gould belt is the giant stellar-gas complex closest to the sun, its stellar component is characterized, along with the stellar associations and diffuse clusters, cold ... More
SO(10) model of standard and dark matterSep 07 2016We consider a novel model for three standard families of left chiral states of quarks and leptons conjointly with a new family of dark matter fermionic particles and a sterile neutrino. It is suggested to use a SO(10) symmetry for description of these ... More
Generalized kinematical symmetries of quantum phase spaceJul 16 2008Continuous symmetries generated with observables of a quantum theory in the Minkowski spacetime are discussed. An example of an originated in this way algebra of observables is the algebra of observables of the canonical quantum theory, that is contained ... More
Confinement and U(1,3) symmetry of color particles in a complex phase spaceNov 26 2003Jul 01 2004It is shown that a universal confining potential for hadron constituents can be obtained with the help of U(1,3) symmetry in a complex phase space. Parameters of this potential are determined on the basis of spectroscopic data for hadrons and results ... More
Left localizations of left Artinian ringsMay 01 2014For an arbitrary left Artinian ring $R$, explicit descriptions are given of all the left denominator sets $S$ of $R$ and left localizations $S^{-1}R$ of $R$. It is proved that, up to $R$-isomorphism, there are only finitely many left localizations and ... More
Nonlinear regimes in mean-field full-sphere dynamoSep 04 2016Sep 15 2016The mean-field dynamo model is employed to study the non-linear dynamo regimes in a fully convective star of mass 0.3$M_{\odot}$ rotating with period of 10 days. For the intermediate value of the parameter of the turbulent magnetic Prandl number, $Pm_{T}=3$ ... More
Helicity--vorticity turbulent pumping of magnetic fields in the solar dynamoNov 11 2012The interaction of helical convective motions and differential rotation in the solar convection zone results in turbulent drift of a large-scale magnetic field. We discuss the pumping mechanism and its impact on the solar dynamo.
Convergence of quantum electrodynamics on the Poincare groupOct 06 2011Extended particles are considered in terms of the fields on the Poincar\'{e} group. Dirac like wave equations for extended particles of any spin are defined on the various homogeneous spaces of the Poincar\'{e} group. Free fields of the spin 1/2 and 1 ... More
Extragalactic background light absorption signal in the TeV gamma-ray spectra of blazarsAug 09 1999Recent observations of the TeV gamma-ray spectra of the two closest active galactic nuclei (AGNs), Markarian 501 (Mrk 501) and Markarian 421 (Mrk 421), by the Whipple and HEGRA collaborations have stimulated efforts to estimate or limit the spectral energy ... More
Novel approach to a perfect lensNov 26 2008Feb 19 2009Within the framework of an exact analytical solution of Maxwell equations in a space domain, it is shown that optical scheme based on a slab with negative refractive index ($n=-1$) (Veselago lens or Pendry lens) does not possess focusing properties in ... More
Search for TeV annihilation radiation from supersymmetric dark matter in nearby galaxiesMay 29 2003During the 2002-2003 observing season the Whipple 10m imaging atmospheric Cerenkov telescope was used to search for dark matter annihilation radiation in four nearby galaxies: M32, M33, Draco, and Ursa Minor. Scientific motivations for this choice of ... More
Constraints for quasi-elastic neutron reflections in the range dE~10^(-12)-10^(-9) eVFeb 10 2005A restrictive constraint for any quasi-elastic process was obtained in the previously inaccessible energy range dE~10^(-12)-3x10^(-10) eV for reflections of ultracold neutrons from surfaces in the experiement on neutron quantum states in the earth's gravitational ... More
Electric fields at the quark surface of strange stars in the color-flavor locked phaseAug 12 2004Oct 14 2004It is shown that extremely strong electric fields may be generated at the surface of strange quark matter in the color-flavor locked phase because of the surface effects. Some properties of strange stars made of this matter are briefly discussed.
On the persistent X-ray emission from the soft gamma-ray repeatersDec 10 1996It is suggested that the persistent X-ray emission from the soft gamma-ray repeaters is the thermal radiation of neutron stars which is enhanced by a factor of 10 or more due to the effect of a very strong magnetic field on the thermal structure of the ... More
Experimental study of a transformer with superconducting elements for fault current limitation and energy redistributionApr 19 2005Numerous proposed and developed superconducting fault current limiters and self-limiting transformers limit successfully fault currents but do not provide uninterrupted supplying of consumers. A design investigated in the work combines the functions of ... More
Young Stars in the Camelopardalis Dust and Molecular Clouds. I. The Cam OB1 AssociationMar 17 2008Mar 31 2008The distribution of dust and molecular clouds in the direction of Galactic longitudes 132--158 deg and latitudes pm 12 deg is investigated. The maps of dust distribution in the area were plotted from the following surveys: the star counts in the DSS I ... More
On the instability of classical dynamics in theories with higher derivativesDec 25 2006Jan 09 2007The development of instability in the dynamics of theories with higher derivatives is traced in detail in the framework of the Pais-Uhlenbeck fourth oder oscillator. For this aim the external friction force is introduced in the model and the relevant ... More
Boundary conditions at spatial infinity for fields in Casimir calculationsNov 02 2005The importance of imposing proper boundary conditions for fields at spatial infinity in the Casimir calculations is elucidated.
The Association of PSR B1757-24 and the SNR G5.4-1.2Oct 14 2003The association of PSR B1757-24 and the supernova remnant (SNR) G5.4-1.2 was recently questioned by Thorsett et al. (2002) on the basis of proper motion measurements of the pulsar and the "incorrect" orientation of the vector of pulsar transverse velocity ... More
On the origin of the hypervelocity runaway star HD271791Sep 27 2009We discuss the origin of the runaway early B-type star HD271791 and show that its extremely high velocity (\simeq 530-920 km/s) cannot be explained within the framework of the binary-supernova ejection scenario. Instead, we suggest that HD271791 attained ... More
Neutron Stars in Supernova Remnants and BeyondDec 26 2002We discuss a concept of off-centred cavity supernova explosion as applied to neutron star/supernova remnant associations and show how this concept could be used to preclude the anti-humane decapitating the Duck (G5.4-1.2 + G5.27-0.9) and dismembering ... More
Installing of cosmological constantAug 05 2013Jan 14 2014An artificial scale of observable cosmological constant is dynamically related to its natural bare value due to an installation of relevant coherent state for the inflationary field in a finite volume of early Universe, because of exponential suppression ... More
Extra charmonium states as bag-quarkoniaMay 28 2008Jun 06 2008Exotic states in the charmonium family are systematically treated in the framework of simplest model with an effective coulomb-like interaction of heavy quark and antiquark in the presence of static excitation of quark-gluon modes responsible for a nonperturbative ... More
A quantum mass-spectrum of Kerr black hole: superstringsDec 23 2004Jan 12 2005Using thermal quantization of geodesics confined under horizons and reasonable conjecture on massless modes, we evaluate quantum spectrum of Kerr black hole masses compatible with superstring symmetries.
Radial geodesics as a microscopic origin of black hole entropy. II: Features of Reissner--Nordstrom black holeDec 21 2004Jan 04 2005The entropy of charged black hole is calculated by using the partition function evaluated at radial geodesics confined under horizons. We establish two quantum phase states inside the black hole and a transition between them.