Results for "Natalia Dubrovinskaia"

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Pressure induced Hydrogen-Hydrogen interaction in metallic FeH revealed by NMRFeb 08 2019Knowledge of the behavior of hydrogen in metal hydrides is the key for understanding their electronic properties. So far, no experimental methods exist to access these properties beyond 100 GPa, where high-Tc superconductivity emerges. Here, we present ... More
Detection of melting by in-situ observation of spherical-drop formation in laser-heated diamond-anvil cellsApr 07 2011A simple method for detection of melting event in laser-heated diamond anvil cells (DACs) is introduced. The melting is registered optically by the formation of spherical drops of the investigated material as heated in an inert pressure transmitting medium. ... More
Novel non-magnetic hard boride Co5B16 synthesized under high pressureApr 09 2014A first cobalt boride with the Co:B ratio below 1:1, Co5B16, was synthesized under high-pressure high-temperature conditions. It has a unique orthorhombic structure (space group Pmma, a = 19.1736(12), b = 2.9329(1), and c = 5.4886(2) {\AA}, R1 (all data) ... More
Lattice dynamics of coesiteApr 10 2013Apr 11 2013The lattice dynamics of coesite has been studied by a combination of diffuse x-ray scattering, inelastic x-ray scattering and an ab initio lattice dynamics calculation. The combined technique gives access to the full lattice dynamics in harmonic description ... More
Pressure induced crossing of the core-levels in 5d metalsSep 24 2015Pressure induced interaction between core electrons, the core level crossing (CLC) transition has been observed in hcp Os at P~400 GPa [L. Dubrovinksy, et al., Nature 525, 226-229 (2015)]. In this work, we carry out a systematic study of the influence ... More
About integrability of almost complex structures on strictly Nearly Kähler 6-manifoldsMay 06 2013We show that any almost complex structure, positively tamed with $\omega$ on nearly K\"{a}hler 6-manifold $(M,g,J,\omega)$ is not integrable
Loops on polyhedral products and diagonal arrangementsJan 19 2009In this paper we establish a connection between the loop space homology of the generalization of wedge defined by a simplicial complex K (so called polyhedral product) and the homology of certain diagonal arrangements associated with K. We illustrate ... More
On estimation of analytic density in L_pOct 10 2011The problem of estimation of analytic density function using L_p minimax risk is considered. A kernel-type estimator of an unknown density function is proposed and the upper bound on its limiting local minimax risk is established. Our result is consistent ... More
Topological constraints on stabilized flux vacuaMar 16 2005May 11 2005We study the influence of four-form fluxes on the stabilization of the Kahler moduli in M-theory compactified on a Calabi-Yau four-fold. We find that, under certain non-degeneracy condition on the flux, M5-instantons of a new topological type generate ... More
Constrained energy problems with external fields for infinite dimensional vector measuresOct 11 2010We consider a constrained minimal energy problem with an external field over noncompact classes of infinite dimensional vector measures on a locally compact space. The components are positive measures (charges) that are constrained from above, satisfy ... More
Constrained energy problems with external fieldsJan 25 2010Given a positive definite kernel in a locally compact space, we study a minimal energy problem in the presence of an external field over the class of all nonnegative Radon measures that are supported by a given closed noncompact set, satisfy certain normalizing ... More
Necessary and sufficient conditions for the solvability of the Gauss variational problem for infinite dimensional vector measuresJul 03 2012We continue our investigation of the Gauss variational problem for infinite dimensional vector measures associated with a condenser $(A_i)_{i\in I}$. It has been shown in Potential Anal., DOI:10.1007/s11118-012-9279-8 that, if some of the plates (say ... More
Equilibrium problems for infinite dimensional vector potentials with external fieldsNov 04 2009The study deals with a minimal energy problem in the presence of an external field over noncompact classes of vector measures of infinite dimension in a locally compact space. The components are positive measures (charges) satisfying certain normalizing ... More
Lightlike foliations on Lorentzian manifolds with weakly irreducible holonomy algebraJun 06 2005We study the lightlike foliations that appear on Lorentzian manifolds with weakly irreducible not irreducible holonomy algebra. We give global structure equations for the foliation that generalize the Gauss and Weingarten equations for one lightlike hypersurface. ... More
An inverse problem for the non-self-adjoint matrix Sturm-Liouville operatorJul 14 2014The inverse problem of spectral analysis for the non-self-adjoint matrix Sturm-Liouville operator on a finite interval is investigated. We study properties of the spectral characteristics for the considered operator, and provide necessary and sufficient ... More
Special Partial GraphsMay 31 2013The attempts to prove the Four Color Problem last for long years. A little hope arises that the properties of the minimal partial triangulations will be very useful for the solution of the Four Color Problem. That is why the material of this paper is ... More
Interior capacities of condensers with infinitely many plates in a locally compact spaceJun 24 2009The study deals with the theory of interior capacities of condensers in a locally compact space, a condenser being treated here as a countable, locally finite collection of arbitrary sets with the sign +1 or -1 prescribed such that the closures of opposite-signed ... More
Coisotropic Branes in Toric Calabi-Yau 3-foldsOct 09 2014We study disk-instantons ending on coisotropic branes preserved by real torus action in toric Calabi-Yau 3-folds. In particular, we find fermion zero modes on disk multi-covers ending on a coisotropic brane in local P^1 geometry with normal bundle (-a,a-2). ... More
K-theory of locally finite graph $C^*$-algebrasJul 22 2010Apr 24 2013We calculate the K-theory of the Cuntz-Krieger algebra ${\cal O}_E$ associated with an infinite, locally finite graph, via the Bass-Hashimoto operator. The formulae we get express the Grothendieck group and the Whitehead group in purely graph theoretic ... More
The space of leftinvariant orthogonal almost complex structures on 6-dimensional Lie groupsJan 14 2012Nov 02 2012The space $\mathcal{Z}$ of leftinvariant orthogonal almost complex structures, keeping the orientation, on 6-dimensional Lie groups is researched. To get explicit view of this space elements the isomorphism of $\mathcal{Z}$ and $\mathbb{C}P^3$ is used. ... More
Mechanism of orbital reconstruction at the interfaces of transition metal oxidesJan 28 2009Jul 18 2009Orbital reconstruction at interfaces between YBa2Cu3O6 and SrO-terminated SrTiO3 is studied using local spin density approximation (LSDA) with intra-atomic Coulomb repulsion (LSDA+U). The change of population of interfacial Cu 3d orbitals results in stabilization ... More
Concern Regarding "A Non-Inflationary Solution to the Entropy Problem of Standard Cosmology."Mar 03 2008Jan 07 2009We discuss the entropy and the size/homogeneity/horizon problems in power-law expanding universes with one scale initial conditions. We set the minimal scale $\Lambda = 10^{25}$ GeV at which a non-inflationary solution is possible and show that the radiation ... More
Effect of metallicity on low mass X-ray binaries in globular clustersSep 18 2005We propose that the observed difference in the formation rates of bright low-mass X-ray binaries in metal-rich and metal-poor globular clusters can be explained by taking into account the difference in the stellar structure of main sequence donors with ... More
Low Mass X-ray Binaries and Metallicity Dependence: Story of FailuresSep 18 2005Observations of galactic and extra-galactic globular clusters have shown that on average metal-rich clusters are ~3 times as likely to contain a bright X-ray source than their metal-poor counterparts. We propose that this can be explained by taking into ... More
A note on Wilson-'t Hooft operatorsOct 14 2011We find the basic ingredients required to compute the Operator Product Expansion of Wilson-'t Hooft operators in N=4 super-Yang-Mills theory with gauge group G=PSU(3). These include the geometry of certain moduli spaces of BPS configurations in the presence ... More
Inverse scattering on the line for the matrix Sturm-Liouville equationDec 19 2015The inverse scattering problem is studied for the matrix Sturm-Liouville equation on the line. Necessary and sufficient conditions for the scattering data are obtained.
The Pulsar in the Crab NebulaNov 16 2015The Crab pulsar belongs to one of the most studied stellar objects in the sky. Since its accidental detection in 1968, its pulsed emission has been observed throughout most of the electromagnetic spectrum. Although currently one of more than 2000 known ... More
Matrix Sturm-Liouville equation with a Bessel-type singularity on a finite intervalFeb 22 2016The matrix Sturm-Liouville equation on a finite interval with a Bessel-type singularity in the end of the interval is studied. Special fundamental systems of solutions for this equation are constructed: analytic Bessel-type solutions with the prescribed ... More
An inverse problem for the matrix quadratic pencil on a finite intervalJan 13 2013We consider a quadratic matrix boundary value problem with equations and boundary conditions dependent on a spectral parameter. We study an inverse problem that consists in recovering the differential pencil by the so-called Weyl matrix. We obtain asymptotic ... More
Low-Mass X-ray Binaries in Globular Clusters: Puzzles and SolutionsJan 10 2013In dense stellar systems, dynamical interactions between objects lead to frequent formation of exotic stellar objects, unusual binaries, and systems of higher multiplicity. They are especially important for the formation of low mass X-ray binaries (LMXBs), ... More
Binary Evolution: Roche Lobe Overflow and Blue StragglersJun 13 2014One of the principal mechanisms that is responsible for the origin of blue stragglers is mass transfer that takes place while one of the binary companions overfills its Roche lobe. In this Chapter, we overview the theoretical understanding of mass transfer ... More
Fractional Repetition and Erasure Batch CodesMay 04 2014Oct 20 2014Batch codes are a family of codes that represent a distributed storage system (DSS) of $n$ nodes so that any batch of $t$ data symbols can be retrieved by reading at most one symbol from each node. Fractional repetition codes are a family of codes for ... More
Common envelope: the progress and the pitfallsAug 04 2011The common envelope event is one of the most important and uncertain evolutionary stages that lead to formation of compact binaries. While the problem is almost 30 years old, its theoretical foundation did not progress much from the first proposed consideration. ... More
Spectral Analysis for the Matrix Sturm-Liouville Operator on a Finite IntervalAug 25 2010Nov 12 2011The inverse spectral problem is investigated for the matrix Sturm-Liouville equation on a finite interval. Properties of spectral characteristics are provided, a constructive procedure for the solution of the inverse problem along with necessary and sufficient ... More
On connection between division sequences and presentations of a free groupMay 20 2010May 24 2010This paper describes a simple method for estimating lower bounds on the number of classes of equivalence for a special kind of integer sequences, called division sequences. The method is based on adding group structure to classes of equivalence and studying ... More
Coding Theory and Projective SpacesMay 22 2008Sep 08 2011The projective space of order $n$ over a finite field $\F_q$ is a set of all subspaces of the vector space $\F_q^{n}$. In this work, we consider error-correcting codes in the projective space, focusing mainly on constant dimension codes. We start with ... More
A note on the moduli-induced gravitino problemMar 30 2007Jan 08 2009The cosmological moduli problem has been recently reconsidered. Papers [1,2] show that even heavy moduli (m_\phi > 10^5 GeV) can be a problem for cosmology if a branching ratio of the modulus into gravitini is large. In this paper, we discuss the tachyonic ... More
Left-invariant almost nearly Kähler structures on $SU(2)\times SU(2)$ in the tetrahedron visualization for $CP^3$Aug 29 2006Jun 04 2008The set of maximal non-integrable structures $(SU(2)\times SU(2),B,I)$, where $B$ is Killing-Cartan metric is described as subset of $\mathbb{CP}^3$. The visualization of complex projective space $\mathbb{CP}^3$ as tetrahedron which edges and faces are ... More
Search for B+ -> K+ l+ l- and B0 -> K*0 l+ l-Oct 27 2000Using a sample of 3.7 x 10^6$ Upsilon(4S) -> B Bbar events collected with the BaBar detector at the PEP-II storage ring, we search for the electroweak penguin decays B+ -> K+ e+ e-, B+ -> K+ mu+ mu-, B0 -> K*0 e+ e-, and B0 -> K*0 mu+ mu-. We observe ... More
Minimizing measures on condensers of infinitely many platesJan 25 2010The study deals with a minimal energy problem over noncompact classes of infinite dimensional vector measures in a locally compact space. The components are positive measures (charges) satisfying certain normalizing assumptions and supported by given ... More
Interior capacities of condensers in locally compact spacesFeb 03 2009The study is motivated by the known fact that, in the noncompact case, the main minimum-problem of the theory of interior capacities of condensers in a locally compact space is in general unsolvable, and this occurs even under very natural assumptions ... More
An inverse problem for the differential operator on the graph with a cycle with different orders on different edgesSep 20 2013Jan 12 2014We consider a variable order differential operator on a graph with a cycle. We study the inverse spectral problem for this operator by the system of spectra. The main results of the paper are the uniqueness theorem and the constructive procedure for the ... More
Recovery of the matrix quadratic differential pencil from the spectral dataSep 21 2015We consider a pencil of matrix Sturm-Liouville operators on a finite interval. We study properties of its spectral characteristics and inverse problems that consist in recovering of the pencil by the spectral data: eigenvalues and so--called weight matrices. ... More
Extremes Control of Complex Systems With Applications to Social NetworkFeb 17 2015The control and risk assessment in complex information systems require to take into account extremes arising from nodes with large node degrees. Various sampling techniques like a Page Rank random walk, a Metropolis-Hastings Markov chain and others serve ... More
Consistency of the posterior distribution in generalised linear inverse problemsNov 14 2012Apr 19 2013For ill-posed inverse problems, a regularised solution can be interpreted as a mode of the posterior distribution in a Bayesian framework. This framework enriches the set the solutions, as other posterior estimates can be used as a solution to the inverse ... More
Evolution of Binaries in Dense Stellar SystemsJan 14 2011In contrast to the field, the binaries in dense stellar systems are frequently not primordial, and could be either dynamically formed or significantly altered from their primordial states. Destruction and formation of binaries occur in parallel all the ... More
Probability density function and detection threshold in high contrast imaging with partially polarized lightJun 05 2009We obtain an expression for the probability density function (PDF) of partially developed speckles formed by light with an arbitrary degree of polarization. From the probability density we calculate the detection threshold corresponding to the 5sigma ... More
Computing the tree number of a cut-outerplanar graphJun 02 2009While the notion of arboricity of a graph is well-known in graph theory, very few results are dedicated to the minimal number of trees covering the edges of a graph, called the tree number of a graph. In this paper we propose a method for computing in ... More
Comparison of the Discriminatory Processor Sharing PoliciesMar 14 2008Apr 25 2008Discriminatory Processor Sharing policy introduced by Kleinrock is of a great interest in many application areas, including telecommunications, web applications and TCP flow modelling. Under the DPS policy the job priority is controlled by the vector ... More
Low mass X-ray binaries with pre-main sequence companionsNov 07 2006In this Letter we examine the idea that a subset of short-period black-hole low-mass X-ray binaries could be powered by the mass transfer from pre-main sequence donors. As the star contracts towards the main sequence, the strong magnetic fields operate ... More
An inverse spectral problem for the matrix Sturm-Liouville operator on the half-lineDec 18 2014The matrix Sturm-Liouville operator with an integrable potential on the half-line is considered. We study the inverse spectral problem, which consists in recovering of this operator by the Weyl matrix. The main result of the paper is the necessary and ... More
Properties of the dual planar triangulationsDec 01 2012Dec 26 2012This article is devoted to the properties of the planar triangulations. The conjugated planar triangulation will be introduced and on the base of the properties, which were achieved by the other authors there will be proved some theorems, which will show ... More
Modulation of Superconducting Properties by Ferroelectric Polarization in Confined FE-S-FE FilmsNov 17 2003Sep 30 2004We show that the electric polarization at the interface with ultrathin superconducting (S) films sandwiched between ferroelectric (FE) layers allows achievement of substantially stronger modulation of inner carrier density and superconducting transition ... More
Constrained Gauss variational problem for condensers with touching platesMay 11 2015We study a constrained minimum energy problem with an external field relative to the Riesz kernel of an arbitrary order for a generalized condenser with touching oppositely-charged plates. Conditions sufficient for the solvability of the problem are obtained. ... More
Spectral networks and higher web-like structuresSep 09 2014We derive traffic rule for spectral networks for A_2 theory for Riemann surface with punctures and use it to study in details the moduli space M of flat GL(3,C) connections on P^1 with 3 full punctures. We apply the simplified traffic rule to find the ... More
Geometric interpretation of the large N=4 indexSep 16 2004We study WZW models with the large N=4 superconformal symetry. Our main result is a geometric interpretation of the large N=4 index. In particular, we find that states contributing to the index belong to spectral flow orbits of special RR ground states. ... More
High frequency asymptotics of global vibrations in a problem with concentrated massApr 16 2008We consider an elastic system containing a small region where the density is very much higher then elsewhere. Such system possesses two types of eigenvibrations, which are local and global vibrations. Complete asymptotic expansions of global eigenvibrations ... More
Spectral synthesis for the differentiation operator in the Schwartz spaceJan 07 2016We consider the spectral synthesis problem for the differentiation operator D=d/dt in the Schwartz space E(a;b) and the dual problem of local description for closed submodules in a special module of entire functions.
Peierls distortion, magnetism, and high hardness of manganese tetraborideDec 25 2013We report crystal structure, electronic structure, and magnetism of manganese tetraboride, MnB4, synthesized under high-pressure high-temperature conditions. In contrast to superconducting FeB4 and metallic CrB4, which are both orthorhombic, MnB4 features ... More
Discovery of a superhard iron tetraboride superconductorApr 18 2013Single crystals of novel orthorhombic (space group Pnnm) iron tetraboride FeB4 were synthesised at pressures above 8 GPa and high temperatures. Magnetic susceptibility measurements demonstrated bulk superconductivity below 2.9 K. The putative isotope ... More
Inverse Approach In The Study Of Ordinary Differential EquationsFeb 26 2009We extend the Eruguin result exposed in the paper "Construction of the whole set of ordinary differential equations with a given integral curve" published in 1952 and construct a differential system in $\Bbb{R}^N$ which admits a given set of the partial ... More
A Gauge Field Theory of Continuous-Spin ParticlesFeb 13 2013Nov 01 2013We propose and quantize a local, covariant gauge-field action that unifies the description of all free helicity and continuous-spin degrees of freedom in a simple manner. This is the first field-theory action of any kind for continuous spin particles; ... More
On the Theory of Continuous-Spin Particles: Helicity Correspondence in Radiation and ForcesFeb 06 2013Nov 01 2013We have recently shown that continuous-spin particles (CSPs) have covariant single-emission amplitudes with the requisite properties to mediate long-range forces. CSPs, the most general massless particle type consistent with Lorentz symmetry, are characterized ... More
Optimal Fractional Repetition Codes and Fractional Repetition Batch CodesJan 21 2015Fractional repetition (FR) codes is a family of codes for distributed storage systems (DSS) that allow uncoded exact repairs with minimum repair bandwidth. In this work, we consider a bound on the maximum amount of data that can be stored using an FR ... More
Large Constant Dimension Codes and LexicodesMar 25 2010Constant dimension codes, with a prescribed minimum distance, have found recently an application in network coding. All the codewords in such a code are subspaces of $\F_q^n$ with a given dimension. A computer search for large constant dimension codes ... More
Error-Correcting Codes in Projective Spaces via Rank-Metric Codes and Ferrers DiagramsJul 30 2008Mar 14 2009Coding in the projective space has received recently a lot of attention due to its application in network coding. Reduced row echelon form of the linear subspaces and Ferrers diagram can play a key role for solving coding problems in the projective space. ... More
Magnetic Schrödinger operators on periodic discrete graphsDec 27 2015Nov 26 2016We consider magnetic Schr\"odinger operators with periodic magnetic and electric potentials on periodic discrete graphs. The spectrum of the operators consists of an absolutely continuous part (a union of a finite number of non-degenerate bands) plus ... More
Adaptive Homing is in PApr 09 2015Homing preset and adaptive experiments with Finite State Machines (FSMs) are widely used when a non-initialized discrete event system is given for testing and thus, has to be set to the known state at the first step. The length of a shortest homing sequence ... More
Nonlinear waves in double-stranded DNANov 24 2004Dec 21 2004We propose a nonlinear model derived from first principles, to describe bubble dynamics of DNA. Our model equations include a term derived from the dissipative effect of intermolecular vibrational modes. Such modes are excited by the propagating bubble, ... More
A two-dimensional slice through the parameter space of two-generator Kleinian groupsDec 19 2005We describe all real points of the parameter space of two-generator Kleinian groups with a parabolic generator, that is, we describe a certain two-dimensional slice through this space. In order to do this we gather together known discreteness criteria ... More
On the Quantum Creation of Matter in the Expanding UniverseMay 09 2011Quantum Action Principle which has been used as a ground for a probabilistic interpretation of one-particle relativistic quantum mechanics \cite{GLL} is applied to quantum cosmology. The quantum creation of matter in a minisuperspace model with one homogeneous ... More
On maxima of stationary fieldsOct 10 2018Oct 15 2018Let $\{X_{\mathbf{n}} : \mathbf{n}\in\mathbb{Z}^d\}$ be a weakly dependent stationary field with maxima $M_{A} := \sup\{X_{\mathbf{i}} : \mathbf{i}\in A\}$ for finite $A\subset\mathbb{Z}^d$ and $M_{\mathbf{n}} := \sup\{X_{\mathbf{i}} : \mathbf{1} \leq ... More
An inverse problem for Sturm-Liouville operators on trees with partial information given on the potentialsNov 15 2017We consider Sturm-Liouville operators on geometrical graphs without cycles (trees) with singular potentials from the class $W_2^{-1}$. We suppose that the potentials are known on a part of the graph, and study the so-called partial inverse problem, which ... More
Adaptive density estimation based on a mixture of GammasMay 26 2016Sep 16 2017We consider the problem of Bayesian density estimation on the positive semiline for possibly unbounded densities. We propose a hierarchical Bayesian estimator based on the gamma mixture prior which can be viewed as a location mixture. We study convergence ... More
The Slow Merger of Massive StarsOct 16 2002We study the complete merger of two massive stars inside a common envelope and the subsequent evolution of the merger product, a rapidly rotating massive supergiant. Three qualitatively different types of mergers have been identified and investigated ... More
Optimal Motion of Flexible Objects with Oscillations Elimination at the Final PointJun 08 2016In this article, a theoretical justification of one type of skew-symmetric optimal translational motion (moving in the minimal acceptable time) of a flexible object carried by a robot from its initial to its final position of absolute quiescence with ... More
Perturbed asymptotic expansions for interior-layer solutions of a semilinear reaction-diffusion problem with small diffusionApr 08 2010Mar 19 2013A semilinear reaction-diffusion two-point boundary value problem, whose second-order derivative is multiplied by a small positive parameter $\eps^2$, is considered. It can have multiple solutions. An asymptotic expansion is constructed for a solution ... More
An extremal problem with applications to testing multivariate independenceDec 03 2010Some problems of statistics can be reduced to extremal problems of minimizing functionals of smooth functions defined on the cube $[0,1]^m$, $m\geq 2$. In this paper, we study a class of extremal problems that is closely connected to the problem of testing ... More
Constructing the Tree-Level Yang-Mills S-Matrix Using Complex FactorizationNov 20 2008A remarkable connection between BCFW recursion relations and constraints on the S-matrix was made by Benincasa and Cachazo in 0705.4305, who noted that mutual consistency of different BCFW constructions of four-particle amplitudes generates non-trivial ... More
On the Theory of Continuous-Spin Particles: Wavefunctions and Soft-Factor Scattering AmplitudesFeb 05 2013Nov 02 2013The most general massless particles allowed by Poincare-invariance are "continuous-spin" particles (CSPs) characterized by a scale \rho, which at \rho=0 reduce to familiar helicity particles. Though known long-range forces are adequately modeled using ... More
Multiphotons and Photon-JetsFeb 28 2012We discuss an extension of the Standard Model with a new vector-boson decaying predominantly into a multi-photon final state through intermediate light degrees of freedom. The model has a distinctive phase in which the photons are collimated. As such, ... More
Enumerative Encoding in the Grassmannian SpaceMar 09 2009Codes in the Grassmannian space have found recently application in network coding. Representation of $k$-dimensional subspaces of $\F_q^n$ has generally an essential role in solving coding problems in the Grassmannian, and in particular in encoding subspaces ... More
Harmonic analysis on spherical homogeneous spaces with solvable stabilizerJun 06 2011Sep 07 2012For all spherical homogeneous spaces G/H, where G is a simply connected semisimple algebraic group and H a connected solvable subgroup of G, we compute the spectra of the representations of G on spaces of regular sections of homogeneous line bundles over ... More
Schrödinger operators on periodic discrete graphsJul 07 2013Dec 23 2013We consider Schr\"odinger operators with periodic potentials on periodic discrete graphs. The spectrum of the Schr\"odinger operator consists of an absolutely continuous part (a union of a finite number of non-degenerated bands) plus a finite number of ... More
The algebra of Wilson-'t Hooft operatorsOct 10 2007We study the Operator Product Expansion of Wilson-'t Hooft operators in a twisted N=4 super-Yang-Mills theory with gauge group G. The Montonen-Olive duality puts strong constraints on the OPE and in the case G=SU(2) completely determines it. From the ... More
Surface operators in 3d Topological Field Theory and 2d Rational Conformal Field TheoryDec 04 2010We study surface operators in 3d Topological Field Theory and their relations with 2d Rational Conformal Field Theory. We show that a surface operator gives rise to a consistent gluing of chiral and anti-chiral sectors in the 2d RCFT. The algebraic properties ... More
A Bayesian Approach to Classifying Supernovae With ColorSep 20 2009Upcoming large-scale ground- and space- based supernova surveys will face a challenge identifying supernova candidates largely without the use of spectroscopy. Over the past several years, a number of supernova identification schemes have been proposed ... More
Exact conservation laws for truncated gyrokinetic Vlasov-Poisson equationsJun 28 2013The purpose of the current work is adapting the results of the Noether method derivation of momentum transport equation for the gyrokinetic Vlasov-Poisson system to numerical implementations. In particular, we are considering the delta-f truncated Gyrokinetic ... More
The impurity problem in a bilayer system of dipolesJun 24 2013Nov 17 2013We consider a bilayer geometry where a single impurity moves in a two-dimensional plane and is coupled, via dipolar interactions, to a two-dimensional system of fermions residing in the second layer. Dipoles in both layers point in the same direction ... More
Electron-phonon coupling in a two-dimensional inhomogeneous electron gas: consequences for surface spectral propertiesAug 27 2007Aug 12 2008We investigate the coupling of an inhomogeneous electron system to phonons. The properties of an electronic system composed of a mixture of microscopic ordered and disordered islands are changed fundamentally by a phonon mode. In high-Tc cuprates, such ... More
Brane gas-driven bulk expansion as a precursor stage to brane inflationDec 05 2005Apr 25 2006We propose a new way of obtaining slow-roll inflation in the context of higher dimensional models motivated by string and M theory. In our model, all extra spatial dimensions are orbifolded. The initial conditions are taken to be a hot dense bulk brane ... More
The classification problem for graphs and lattices is wildAug 29 2010Jun 16 2014We prove that the classification problem for graphs and several types of algebraic lattices (distributive, congruence and modular) up to isomorphism contains the classification problem for pairs of matrices up to simultaneous similarity.
The proof of the Kontsevich periodicity conjecture on noncommutative birational transformationsMay 08 2013May 16 2014For an arbitrary associative unital ring $R$, let $J_1$ and $J_2$ be the following noncommutative birational partly defined involutions on the set $M_3(R)$ of $3\times 3$ matrices over $R$: $J_1(M)=M^{-1}$ (the usual matrix inverse) and $J_2(M)_{jk}=(M_{kj})^{-1}\,$ ... More
Two problems from the Polishchuk and Positselski book on Quadratic algebrasJun 28 2016In the book 'Quadratic algebras' by Polishchuk and Positselski [23] algebras with a small number of generators (n=2,3) are considered. For some number r of relations possible Hilbert series are listed, and those appearing as series of Koszul algebras ... More
Homology of non-$k$-overlapping discsMar 04 2014In this paper we describe the homology and cohomology of some natural bimodules over the little discs operad, whose components are configurations of non-$k$-overlapping discs. At the end we briefly explain how this algebraic structure intervenes in the ... More
Graphs of relations and Hilbert seriesJan 19 2008We are discussing certain combinatorial and counting problems related to quadratic algebras. First we give examples which confirm the Anick conjecture on the minimal Hilbert series for algebras given by n generators and n(n-1)/2 relations for n less or ... More
Adaptive variable selection in nonparametric sparse additive modelsAug 26 2015We consider the problem of recovery of an unknown multivariate signal $f$ observed in a $d$-dimensional Gaussian white noise model of intensity $\varepsilon$. We assume that $f$ belongs to a class of smooth functions ${\cal F}^d\subset L_2([0,1]^d)$ and ... More
Representation spaces of the Jordan planeSep 04 2012We investigate relations between the properties of an algebra and its varieties of finite-dimensional module structures, on the example of the Jordan plane $R=k<x,y>/ (xy-yx-y^2)$. Complete description of irreducible components of the representation variety ... More
Vortex Splitting in Subcritical Nonlinear Schrodinger EquationJan 17 2008Vortices and axisymmetric vortex rings are considered in the framework of the subcritical nonlinear Schrodinger equations. The higher order nonlinearity present in such systems models many-body interactions in superfluid systems and allows one to study ... More
Physics of systems with motivation as an interdisciplinary branch of scienceFeb 22 2009The paper discusses the fundamental characteristics distinguishing the natural and social systems from each other. It considers in detail the basic approaches, prospects, and possibilities of constructing mathematical description for social systems as ... More