Results for "Yakov Kopelevich"

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Dirac and Normal Fermions in Graphite and Graphene: Implications to the Quantum Hall EffectSep 02 2006Jan 12 2007Spectral analysis of Shubnikov de Haas (SdH) oscillations of magnetoresistance and of Quantum Hall Effect (QHE) measured in quasi-2D highly oriented pyrolytic graphite (HOPG) [Phys. Rev. Lett. 90, 156402 (2003)] reveals two types of carriers: normal (massive) ... More
Effect of structural disorder on quantum oscillations in graphiteFeb 06 2017We have studied the effect of structural disorder on the de Haas van Alphen (dHvA) and Shubnikov de Haas (SdH) quantum oscillations measured in single-crystal and highly oriented pyrolytic graphite samples at temperatures down to 30 mK and at magnetic ... More
Unstable and elusive superconductorsMay 28 2015We briefly review earlier and report original experimental results in the context of metastable or possible superconducting materials. We show that applied electric field induces conducting state in Copper Chloride (CuCl) whose characteristics resemble ... More
Magnetization Measurement of a Possible High-Temperature Superconducting State in Amorphous Carbon Doped with SulfurFeb 26 2009Magnetization M(T,H) measurements performed on thoroughly characterized commercial amorphous carbon powder doped with sulfur (AC-S), revealed the occurrence of an inhomogeneous superconductivity (SC) below T_c = 38 K. The constructed magnetic field-temperature ... More
Graphene Physics in GraphiteDec 24 2007Jan 05 2008Single layers of carbon dubbed "graphenes", from which graphite is built, have attracted broad interest in the scientific community because of recent exciting experimental results. Graphene is interesting from a fundamental research perspective, as well ... More
Graphite vs graphene: scientific backgroundNov 21 2010Nobel Prize in Physics 2010 was given for "groundbreaking experiments regarding the two-dimensional material graphene." In fact, before graphene has been extracted from graphite and measured, some of its fundamental physical properties have already been ... More
Comment on "Consistent Interpretation of the Low-Temperature Magnetotransport in Graphite Using the Slonczewski-Weiss-McClure 3D Band-Structure Calculations" (arXiv:0902.1925)Jul 12 2009Nov 12 2009In 2004 we have shown that substantial part of conductivity in graphite is provided by holes with massless linear spectrum - Dirac Fermions that coexist with massive normal carriers - electrons. In a recent Letter [Phys. Rev. Lett. 102, 166403 (2009), ... More
Nernst effect in semi-metals: the meritorious heaviness of electronsNov 06 2006Feb 21 2007We present a study of electric, thermal and thermoelectric transport in elemental Bismuth, which presents a Nernst coefficient much larger than what was found in correlated metals. We argue that this is due to the combination of an exceptionally low carrier ... More
Phase analysis of quantum oscillations in graphiteFeb 02 2004Nov 04 2004The quantum de Haas van Alphen (dHvA) and Shubnikov de Haas (SdH) oscillations measured in graphite were decomposed by pass-band filtering onto contributions from three different groups of carriers. We develop the two-dimensional phase analysis method ... More
Signatures of Electron Fractionalization in Ultraquantum BismuthFeb 14 2008Because of the long Fermi wavelength of itinerant electrons, the quantum limit of elemental bismuth (unlike most metals) can be attained with a moderate magnetic field. The quantized orbits of electrons shrink with increasing magnetic field. Beyond the ... More
Oscillating Nernst-Ettingshausen effect in Bismuth across the quantum limitDec 05 2006Apr 27 2007In elemental Bismuth, 10$^5$ atoms share a single itinerant electron. Therefore, a moderate magnetic field can confine electrons to the lowest Landau level. We report on the first study of metallic thermoelectricity in this regime. The main thermoelectric ... More
Local and Global Superconductivity in BismuthSep 14 2011We performed magnetization M(H,T) and magnetoresistance R(T,H) measurements on powdered (grain size ~ 149 micrometers) as well as highly oriented rhombohedral (A7) bismuth (Bi) samples consisting of single crystalline blocks of size ~ 1x1 mm2 in the plane ... More
Nernst effect and dimensionality in the quantum limitSep 11 2009Nernst effect, the transverse voltage generated by a longitudinal thermal gradient in presence of magnetic field has recently emerged as a very sensitive, yet poorly understood, probe of electron organization in solids. Here we report on an experiment ... More
Ferromagnetism and Superconductivity in Carbon-Based SystemsSep 20 2006In this article we shortly review previous and recently published experimental results that provide evidence for intrinsic, magnetic-impurity-free ferromagnetism and for high-temperature superconductivity in carbon-based materials. The available data ... More
Comment on "Quantum Melting of the Quasi-Two-Dimensional Vortex Lattice in $κ-(ET)_2Cu(NCS)_2$"Jul 04 2001In a recent Letter Mola et al. \cite{mola} reported magnetization measurements $M(H,\theta)$ performed on the organic superconductor $\kappa-$(ET)$_2$Cu(NCS)$_2 (T_c = 9.1$ K) as a function of the magnetic field $H$ applied at different angles $\theta$ ... More
Vortex Lattice Depinning vs. Vortex Lattice Melting: a pinning-based explanation of the equilibrium magnetization jumpFeb 01 2000In this communication we argue that the Vortex Lattice Melting scenario fails to explain several key experimental results published in the literature. From a careful analysis of these results we conclude that the Flux Line Lattice (FLL) does not melt ... More
p-adic uniformization of unitary Shimura varieties IISep 23 1999In this paper we show that certain Shimura varieties, uniformized by the product of complex unit balls, can be p-adically uniformized by the product (of equivariant coverings) of Drinfeld upper half-spaces. We also extend a p-adic uniformization to automorphic ... More
Searching in Dynamic Catalogs on a TreeJul 20 2010In this paper we consider the following modification of the iterative search problem. We are given a tree $T$, so that a dynamic catalog $C(v)$ is associated with every tree node $v$. For any $x$ and for any node-to-root path $\pi$ in $T$, we must find ... More
Infinite-dimensional Lie algebras and the period map for curvesJun 23 1994Jun 29 1994We compute higher-order differentials of the period map for curves and show how they factor through the corresponding higher Kodaira-Spencer classes. Our approach is based on the infinitesimal equivariance of the period map, due to Arbarello and De Concini ... More
Quadratic invariants of the elasticity tensorSep 08 2015We study the quadratic invariants of the elasticity tensor in the framework of its unique irreducible decomposition. The key point is that this decomposition generates the direct sum reduction of the elasticity tensor space. The corresponding subspaces ... More
On skewon modification of light cone structureJul 24 2014Jan 08 2015Electromagnetic media with generic linear response provide a rich class of Lorentz violation models. In the framework of a general covariant metric-free approach, we study electromagnetic wave propagation in these media. We define the notion of an optic ... More
Skewon no-go theoremOct 30 2013Axion modification of the electrodynamics can be considered as produced by an irreducible part of the constitutive pseudotensor. In this paper, we study the modification of wave propagation produced by the second irreducible part called skewon. We introduce ... More
Large deviations of U-empirical Kolmogorov-Smirnov tests, and their efficiencyJun 02 2009Non-degenerate U-empirical Kolmogorov-Smirnov tests are studied and their large deviation asymptotics under the null-hypothesis is described. Several examples of such statistics used for testing goodness-of-fit and symmetry are considered. It is shown ... More
Weinstein manifolds revisitedJul 11 2017Aug 29 2017This is a very biased and incomplete survey of some basic notions, old and new results, as well as open problems concerning Weinstein symplectic manifolds.
Comment on ``New Vortex-Matter Size Effect Observed in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$"Jul 04 2001The Letter of Wang et al. \cite{wan} is related to the recently discovered vanishing of the second magnetization peak (SMP) in high-$T_c$ superconductors reducing the sample size \cite{kope1,kope2,gal}. This phenomenon has been interpreted \cite{kope1,kope2,gal} ... More
G-Graded Central Polynomials and G-Graded Posner's TheoremOct 13 2016Let F be characteristic zero field, G a residually finite group and W a G-prime and PI F-algebra. By constructing G-graded central polynomials for W, we prove the G-graded version of Posner's theorem. More precisely, if S denotes all non-zero degree e ... More
The Lie algebra associated with the lower central series of a right-angled Coxeter groupJan 21 2019We study the lower central series of a right-angled Coxeter group $RC_K$ and the associated Lie algebra $L(RC_K)$. The latter is related to the graph Lie algebra $L_K$. We give an explicit combinatorial description of the first three consecutive factors ... More
Proximity and Josephson effects in superconducting hybrid structuresNov 17 2003Chapter 1: Superconductivity in thin SN bilayers. Chapter 2: Proximity effect in SF systems. Chapter 3: Josephson effect in SFS junctions. Chapter 4: Decoherence due to nodal quasiparticles in d-wave Josephson junctions.
A Fast Algorithm for Three-Dimensional Layers of Maxima ProblemJul 09 2010May 03 2011We show that the three-dimensional layers-of-maxima problem can be solved in $o(n\log n)$ time in the word RAM model. Our algorithm runs in $O(n(\log \log n)^3)$ deterministic time or $O(n(\log\log n)^2)$ expected time and uses O(n) space. We also describe ... More
Codimension-2 surfaces and their Hilbert spaces: low-energy clues for holography from general covarianceJan 26 2009Nov 22 2009We argue that the holographic principle may be hinted at already from low-energy considerations, assuming diffeomorphism invariance, quantum mechanics and Minkowski-like causality. We consider the states of finite spacelike hypersurfaces in a diffeomorphism-invariant ... More
A few remarks about symplectic fillingNov 26 2003Feb 27 2004We show that any compact symplectic manifold (W,\omega) with boundary embeds as a domain into a closed symplectic manifold, provided that there exists a contact plane \xi on dW which is weakly compatible with omega, i.e. the restriction \omega |\xi does ... More
Submillimeter - sized proximity effect in graphite and bismuthFeb 08 2019In this work, we probe the electrical properties of macroscopic graphite and bismuth in which the electrical current is injected via superconducting electrodes, few millimeters apart from each other. Results reveal the induction of a partial superconducting-like ... More
Charge Ordering in Amorphous WO$_{x}$ FilmsJan 11 2007We report on the observation of highly anisotropic viscous electronic conducting phase in amorphous WO$_{1.55}$ films that occurs below a current (I)- and frequency (f)- dependent temperature T*(I, f). At T < T*(I, f) the rotational symmetry of randomly ... More
On the derivation of the equations of motion in theories of gravityJan 02 2001The equations of motion of massive particles in GR are completely determined by the field equation. We utilize the particular form of Einstein's field equation and propose for the $N$-body problem of the equations that are Lorentz invariant a novel algorithm ... More
On the derivation of the equation of motion in a scalar modelDec 12 2000A new method for derivation of the equation of motion from the field equation is proposed. The problem of embedding the singularities in a field satisfying the field equations is discussed.
On a class of invariant coframe operators with application to gravityJul 06 1999Let a differential 4D-manifold with a smooth coframe field be given. Consider the operators on it that are linear in the second order derivatives or quadratic in the first order derivatives of the coframe, both with coefficients that depend on the coframe ... More
Interaction of a Supernova Shock with the other Star in a Binary SystemSep 07 2008Interaction of a fast shock wave generated during a supernova explosion with a magnetized star-companion of the supernova precursor produces a current sheet. We consider the evolution of this current sheet and show that a singularity (shock) is formed ... More
Cooper like paring and energy gap induced by ion electronic polarizabilityJan 24 2016We explore the possibility that the ionic electron polarizabilities of the oxygen ions in the cuprates and the bismutates and the polarizabilities of As and Se ions in the iron pnictides contribute to charge carrier pairing leading to high Tc superconductivity. ... More
Yoneda lemma for complete Segal spacesJan 22 2014Feb 07 2014In this note we formulate and give a self-contained proof of the Yoneda lemma for infinity categories in the language of complete Segal spaces.
Isorotating Baby SkyrmionsSep 17 2013Oct 11 2013We discuss how internal rotation with fixed angular frequency can affect the solitons in the baby Skyrme model in which the global O(3) symmetry is broken to the SO(2). Two particular choices of the potential term are considered, the "old" potential and ... More
Lagrangian capsMar 04 2013We establish an $h$-principle for exact Lagrangian embeddings with concave Legendrian boundary. We prove, in particular, that in the complement of the unit ball $B$ in the standard symplectic $\R^{2n}, 2n\geq 6$, there exists an embedded Lagrangian $n$-disc ... More
Generalized Skyrmions and hairy black holes in asymptotically AdS$_4$ spacetimeDec 06 2016We investigate the properties of spherically symmetric black hole solutions in the generalized Einstein-Skyrme model theory in four-dimensional asymptotically anti-de Sitter space-time. The dependencies of the Skyrmion fields on the cosmological constant ... More
Path connectedness and entropy density of the space of ergodic hyperbolic measuresMay 09 2015Jun 08 2017We show that the space of hyperbolic ergodic measures of a given index supported on an isolated homoclinic class is path connected and entropy dense provided that any two hyperbolic periodic points in this class are homoclinically related. As a corollary ... More
Interaction Between Superconducting and Ferromagnetic Order Parameters in Graphite-Sulfur CompositesApr 07 2004The superconductivity of graphite-sulfur composites is highly anisotropic and associated with the graphite planes. The superconducting state coexists with the ferromagnetism of pure graphite, and a continuous crossover from superconducting to ferromagnetic-like ... More
Distance in the Ellipticity GraphJun 24 2010Aug 08 2013The ellipticity graph of a free group $F$ was defined by I. Kapovich and M. Lustig in order to study the outer automorphism group of $F$, which acts on this graph. The graph was constructed to be analogous to the curve complex of a surface. It is a bipartite ... More
Query Complexity of Correlated EquilibriumJun 11 2013Jul 12 2013We study lower bounds on the query complexity of determining correlated equilibrium. In particular, we consider a query model in which an n-player game is specified via a black box that returns players' utilities at pure action profiles. In this model ... More
Computational Aspects of Private Bayesian PersuasionMar 04 2016We study computational questions in a game-theoretic model that, in particular, aims to capture advertising/persuasion applications such as viral marketing. Specifically, we consider a multi-agent Bayesian persuasion model where an informed sender (marketer) ... More
Communication complexity of approximate Nash equilibriaAug 23 2016Sep 13 2016For a constant $\epsilon$, we prove a poly(N) lower bound on the (randomized) communication complexity of $\epsilon$-Nash equilibrium in two-player NxN games. For n-player binary-action games we prove an exp(n) lower bound for the (randomized) communication ... More
Path connectedness and entropy density of the space of ergodic hyperbolic measuresMay 09 2015We show that the space of hyperbolic ergodic measures of a given index supported on an isolated homoclinic class is path connected and entropy dense provided that any two hyperbolic periodic points in this class are homoclinically related. As a corollary ... More
Optimal Top-k Document RetrievalJul 25 2013Jul 31 2013Let $\mathcal{D}$ be a collection of $D$ documents, which are strings over an alphabet of size $\sigma$, of total length $n$. We describe a data structure that uses linear space and and reports $k$ most relevant documents that contain a query pattern ... More
Full-fledged Real-Time Indexing for Constant Size AlphabetsFeb 17 2013Jul 06 2013In this paper we describe a data structure that supports pattern matching queries on a dynamically arriving text over an alphabet ofconstant size. Each new symbol can be prepended to $T$ in O(1) worst-case time. At any moment, we can report all occurrences ... More
Thermodynamical Formalism Associated with Inducing Schemes for One-dimensional MapsNov 24 2005For a smooth map f of a compact interval I admitting an inducing scheme we establish a thermodynamical formalism, i.e., describe a class of real-valued potential functions $\phi$ on I which admit a unique equilibrium measure $\mu_\phi$. Our results apply ... More
On the commutator subgroup of a right-angled Artin groupFeb 01 2017Dec 19 2018We use polyhedral product models to analyse the structure of the commutator subgroup of a right-angled Artin group. In particular, we provide a minimal set of generators for the commutator subgroup, consisting of special iterated commutators of canonical ... More
Exotics and PWA for piN ScatteringFeb 17 2014Our talk is intended for the session in memory of Mitya Diakonov. The problem is considered of existence of flavor multiplets consisting of multi-quark baryons. We have argued that the S-matrix should have poles, at least Regge ones, with any quantum ... More
Tight Bounds for Online Stable SortingJul 04 2009Although many authors have considered how many ternary comparisons it takes to sort a multiset $S$ of size $n$, the best known upper and lower bounds still differ by a term linear in $n$. In this paper we restrict our attention to online stable sorting ... More
A Way to Measure Very Large Δm for B_s MesonsDec 05 1996While present vertex technology cannot measure x_s much beyond 20, the Standard Model accomodates significantly larger x_s values. This note presents a method to determine very large x_s with present technology. The determination is based upon subtle ... More
Verbally prime T-ideals and graded division algebrasOct 14 2016The notion of verbally prime $T$-ideal or verbally prime algebra is naturally extended to the context of $G$-graded algebras where $G$ is a finite group. It turns out that equivalent definitions for ungraded verbally prime algebras extend to nonequivalent ... More
Partially ordered groups and geometry of contact transformationsOct 13 1999We prove, for a class of contact manifolds, that the universal cover of the group of contact diffeomorphisms carries a natural partial order. It leads to a new viewpoint on geometry and dynamics of contactomorphisms. It gives rise to invariants of contactomorphisms ... More
Graphical potential gamesMay 07 2014Mar 23 2016We study the class of potential games that are also graphical games with respect to a given graph $G$ of connections between the players. We show that, up to strategic equivalence, this class of games can be identified with the set of Markov random fields ... More
Making cobordisms symplecticApr 23 2015May 14 2015We establish an existence $h$-principle for symplectic cobordisms of dimension $2n>4$ with concave overtwisted contact boundary.
Hadamard-Perron theorems and effective hyperbolicityMar 10 2013We prove several new versions of the Hadamard-Perron Theorem, which relates infinitesimal dynamics to local dynamics for a sequence of local diffeomorphisms, and in particular establishes the existence of local stable and unstable manifolds. Our results ... More
Equilibrium Measures for Maps with Inducing SchemesSep 25 2006Jun 04 2008We introduce a class of continuous maps f of a compact metric space I admitting inducing schemes and describe the tower constructions associated with them. We then establish a thermodynamical formalism, i.e., describe a class of real-valued potential ... More
Approximate Nash Equilibria via SamplingJul 18 2013We prove that in a normal form n-player game with m actions for each player, there exists an approximate Nash equilibrium where each player randomizes uniformly among a set of O(log(m) + log(n)) pure strategies. This result induces an $N^{\log \log N}$ ... More
Top-K Color Queries for Document RetrievalJul 08 2010Oct 18 2010In this paper we describe a new efficient (in fact optimal) data structure for the {\em top-$K$ color problem}. Each element of an array $A$ is assigned a color $c$ with priority $p(c)$. For a query range $[a,b]$ and a value $K$, we have to report $K$ ... More
On Generalized Rectangular Fuzzy Model for AssessmentJan 05 2015The article is dedicated to the analysis of the existing models for assessment based of the fuzzy logic centroid technique. A new Generalized Rectangular Model were developed. Some generalizations of the existing models are offered.
Optimal Dynamic Sequence RepresentationsJun 29 2012Feb 01 2013We describe a data structure that supports access, rank and select queries, as well as symbol insertions and deletions, on a string $S[1,n]$ over alphabet $[1..\sigma]$ in time $O(\lg n/\lg\lg n)$, which is optimal even on binary sequences and in the ... More
Polyhedral products and commutator subgroups of right-angled Artin and Coxeter groupsMar 22 2016Sep 01 2016We construct and study polyhedral product models for classifying spaces of right-angled Artin and Coxeter groups, general graph product groups and their commutator subgroups. By way of application, we give a criterion of freeness for the commutator subgroup ... More
Yang-Mills ReplacementAug 24 2016We develop an analog of the harmonic replacement technique of Colding and Minicozzi in the gauge theory context. The idea behind harmonic replacement dates back to Schwarz and Perron, and the technique involves taking a map $v\colon\Sigma\to M$ defined ... More
Stein structures: existence and flexibilityMay 07 2013This survey on the topology of Stein manifolds is an extract from our recent joint book. It is compiled from two short lecture series given by the first author in 2012 at the Institute for Advanced Study, Princeton, and the Alfred Renyi Institute of Mathematics, ... More
Symplectic quasi-states on the quadric surface and Lagrangian submanifoldsJun 12 2010The quantum homology of the monotone complex quadric surface splits into the sum of two fields. We outline a proof of the following statement: The unities of these fields give rise to distinct symplectic quasi-states defined by asymptotic spectral invariants. ... More
The topology of rationally and polynomially convex domainsMay 07 2013Feb 27 2014We give in this article necessary and sufficient conditions on the topology of rationally and polynomially convex domains.
On the injectivity radius in Hofer's geometryApr 16 2014Apr 19 2014In this note we consider the following conjecture: given any closed symplectic manifold $M$, there is a sufficiently small real positive number $\rho$ such that the open ball of radius $\rho$ in the Hofer metric centered at the identity on the group of ... More
The Sparse PCA Problem: Optimality Conditions and AlgorithmsJul 29 2015Sparse principal component analysis (PCA) addresses the problem of finding a linear combination of the variables in a given data set with a sparse coefficients vector that maximizes the variability of the data. This model enhances the ability to interpret ... More
Rotation of quantum liquid without singular vortex linesMay 17 2011Dec 03 2011The operator equations for quantum hydrodynamics are discussed and solved in a simple cylindrical geometry. We find a solution with the velocity curl "frozen" into a density of the liquid in the absence of singular vortex lines. The spectrum of small ... More
Sorted Range ReportingApr 20 2012Apr 25 2012In this paper we consider a variant of the orthogonal range reporting problem when all points should be reported in the sorted order of their $x$-coordinates. We show that reporting two-dimensional points with this additional condition can be organized ... More
Making cobordisms symplecticApr 23 2015Apr 07 2017We establish an existence $h$-principle for symplectic cobordisms of dimension $2n>4$ with concave overtwisted contact boundary.
Duality in finite element exterior calculusJun 30 2018In order to generalize finite element methods to differential forms, Arnold, Falk, and Winther constructed two families of spaces of polynomial differential forms on a simplex $T$, the $\mathcal P_r\Lambda^k(T)$ spaces and the $\mathcal P_r^-\Lambda^k(T)$ ... More
The constitutive tensor of linear elasticity: its decompositions, Cauchy relations, null Lagrangians, and wave propagationAug 05 2012In linear anisotropic elasticity, the elastic properties of a medium are described by the fourth rank elasticity tensor C. The decomposition of C into a partially symmetric tensor M and a partially antisymmetric tensors N is often used in the literature. ... More
Time-Translation Invariance of Scattering Maps and Blue-Shift Instabilities on Kerr Black Hole SpacetimesDec 27 2015In this paper, we provide an elementary, unified treatment of two distinct blue-shift instabilities for the scalar wave equation on a fixed Kerr black hole background: the celebrated blue-shift at the Cauchy horizon (familiar from the strong cosmic censorship ... More
Integer Quantum Hall Effect in GraphiteMar 07 2006Mar 14 2006We present Hall effect measurements on highly oriented pyrolytic graphite that indicate the occurrence of the integer quantum-Hall-effect. The evidence is given by the observation of regular plateau-like structures in the field dependence of the transverse ... More
Non-Standard Limit Theorems in Number TheorySep 30 2010Oct 15 2010We present a limit theorem describing the behavior of a probabilistic model for square-free numbers. The limiting distribution has a density that comes from the Dickman-De Bruijn function and is constant on the interval $[0,1]$. We also provide estimates ... More
On the probability of co-primality of two natural numbers chosen at random (Who was the first to pose and solve this problem?)Aug 18 2016Apr 11 2017The article attempts to demonstrate the rich history of one truly remarkable problem situated at the confluence of probability theory and theory of numbers - finding the probability of co-primality of two randomly selected natural numbers. The goal of ... More
Small Volumes in Compactified String TheoryDec 17 1996We discuss some of the classical and quantum geometry associated to the degeneration of cycles within a Calabi-Yau compactification. In particular, we focus on the definition and properties of quantum volume, especially as it applies to identifying the ... More
Buoyancy storms in a zonal stream on the polar beta-plane: experiments with altimetryApr 11 2013Results from a new series of experiments on flows generated by localized heating in the presence of a background zonal current on the polar beta-plane are presented. The flow induced by a heater without the background zonal flow is in the form of a beta-plume. ... More
Width of the longitudinal magnon in the vicinity of the O(3) quantum critical pointApr 07 2011We consider a three-dimensional quantum antiferromagnet in the vicinity of a quantum critical point separating the magnetically ordered and the magnetically disordered phases. A specific example is TlCuCl$_3$ where the quantum phase transition can be ... More
Dirac Fermions in Graphite: the State of ArtFeb 17 2009Macroscopic concentration of massless charge carriers with linear conic spectrum - Dirac Fermions (DF) - was shown in 2004 to exist in highly oriented pyrolytic graphite (HOPG) and governs its electronic properties. These carriers can have the same nature ... More
Coarse Grained Computations for a Micellar SystemJul 08 2004We establish, through coarse-grained computation, a connection between traditional, continuum numerical algorithms (initial value problems as well as fixed point algorithms) and atomistic simulations of the Larson model of micelle formation. The procedure ... More
Absence of Metal-Insulator-Transition and Coherent Interlayer Transport in oriented graphite in parallel magnetic fieldsJun 28 2002Oct 10 2002Measurements of the magnetoresistivity of graphite with a high degree of control of the angle between the sample and magnetic field indicate that the metal-insulator transition (MIT), shown to be induced by a magnetic field applied perpendicular to the ... More
Extraordinary magnetoresistance in graphite: experimental evidence for the time-reversal symmetry breakingFeb 25 2012The ordinary magnetoresistance (MR) of doped semiconductors is positive and quadratic in a low magnetic field, B, as it should be in the framework of the Boltzmann kinetic theory or in the conventional hopping regime. We observe an unusual highly-anisotropic ... More
On the probability of co-primality of two natural numbers chosen at random (Who was the first to pose and solve this problem?)Aug 18 2016The article attempts to demonstrate the rich history of one truly remarkable problem situated at the confluence of probability theory and theory of numbers - finding the probability of co-primality of two randomly selected natural numbers. The goal of ... More
Ergodic Properties of Square-Free NumbersDec 20 2011Apr 05 2013We construct a natural invariant measure concentrated on the set of square-free numbers, and invariant under the shift. We prove that the corresponding dynamical system is isomorphic to a translation on a compact, Abelian group. This implies that this ... More
On spatial resolution, signal-to-noise and information capacity of linear imaging systemsNov 01 2015Feb 09 2016A simple model for image formation in linear shift-invariant systems is considered, in which both the detected signal and the noise variance are varying slowly compared to the point-spread function of the system. It is shown that within the constraints ... More
A categorical approach to the stable center conjectureJul 17 2013May 15 2015The stable center conjecture asserts that the space of stable distributions in the Bernstein center of a reductive p-adic is closed under convolution. It is closely related to the notion of an L-packet and endoscopy theory. We describe a categorical approach ... More
Local Minima of a Quadratic Binary Functional with a Quasi-Hebbian Connection MatrixDec 22 2010The local minima of a quadratic functional depending on binary variables are discussed. An arbitrary connection matrix can be presented in the form of quasi-Hebbian expansion where each pattern is supplied with its own individual weight. For such matrices ... More
The Polynomial Part of the Codimension Growth of Affine PI AlgebrasOct 29 2015Nov 24 2015Let $F$ be a field of characteristic zero and $W$ be an associative affine $F$-algebra satisfying a polynomial identity (PI). The codimension sequence associated to $W$, $c_n(W)$, is known to be of the form $\Theta (c n^t d^n)$, where $d$ is the well ... More
Percolation model for the superconductor-insulator transition in granular filmsJan 14 2007We study the temperature dependence of the superconductor-insulator transition in granular superconductors. Empirically, these systems are characterized by very broad resistance tails, which depend exponentially on the temperature, and the normal state ... More
Massive Warm/Hot Galaxy Coronae as Probed by OVI, OVII and OVIII AbsorbersFeb 01 2016We construct an analytic phenomenological model for extended warm/hot gaseous coronae of L* galaxies. We aim to reproduce the column densities of highly ionized oxygen ions observed in the ultraviolet and X-ray, as evidence for warm/hot gas in a wide ... More
Flexible LagrangiansOct 05 2015Aug 15 2016We introduce and discuss notions of regularity and flexibility for Lagrangian manifolds with Legendrian boundary in Weinstein domains. There is a surprising abundance of flexible Lagrangians. In turn, this leads to new constructions of Legendrians submanifolds ... More
Indication of Superconductivity at 35 K in Graphite-Sulfur CompositesMay 16 2001Sep 13 2001We report magnetization measurements performed on graphite--sulfur composites which demonstrate a clear superconducting behavior below the critical temperature T$_{c0}$ = 35 K. The Meissner-Ochsenfeld effect, screening supercurrents, and magnetization ... More
Unconventional Landau levels in bulk graphite revealed by Raman spectroscopyJul 08 2008The electronic Raman scattering of bulk graphite at zero magnetic field reveals a structureless signal characteristic of a metal. For T<~100 K and B > 2 T, several peaks at energies scaling linearly with magnetic field were observed and ascribed to transitions ... More