total 80257took 0.11s

Observations of red giants with suspected massive companionsFeb 08 2019Motivated by the existence of binary systems where a stellar-mass black hole is bound to a normal star, we selected four red giants with large radial velocity (RV) variation from the survey of SIM grid stars and monitored their RVs for several months. ... More

Orbital relaxation and excitation of planets tidally interacting with white dwarfsApr 05 2019Observational evidence of white dwarf planetary systems is dominated by the remains of exo-asteroids through accreted metals, debris discs, and orbiting planetesimals. However, exo-planets in these systems play crucial roles as perturbing agents, and ... More

Equilibrium rotation of semiliquid exoplanets and satellitesJul 27 2015A wide range of exoplanet and exomoon models are characterized by a finite average rigidity and a viscosity much lower than the typical values for terrestrials. Such semiliquid bodies may or may not have rigid crusts with permanent figures. Unlike planets ... More

How terrestrial planets traverse spin-orbit resonances: A camel goes through a needle's eyeOct 12 2011Apr 04 2012The dynamical evolution of terrestrial planets resembling Mercury in the vicinity of spin-orbit resonances is investigated using comprehensive harmonic expansions of the tidal torque taking into account the frequency-dependent quality factors and Love ... More

Stability, chaos and entrapment of stars in very wide pairsNov 18 2011Dec 12 2011The relative motion of stars and other celestial objects in very wide pairs, separated by distances of the order of 1 pc, is strongly influenced by the tidal gravitational potential of the Galaxy. The Coriolis component of the horizontal tidal force in ... More

Variability of surface flows on the Sun and the implications for exoplanet detectionApr 08 2010The published Mount Wilson Doppler-shift measurements of the solar velocity field taken in 1967--1982 are revisited with a more accurate model, which includes two terms representing the meridional flow and three terms corresponding to the convective limb ... More

Absolute Nuv magnitudes of Gaia DR1 astrometric stars and a search for hot companions in nearby systemsMay 02 2017Sep 15 2017Accurate parallaxes from Gaia DR1 (TGAS) are combined with GALEX visual Nuv magnitudes to produce absolute Mnuv magnitudes and an ultraviolet HR diagram for a large sample of astrometric stars. A functional fit is derived of the lower envelope main sequence ... More

Why is the Moon synchronously rotating?May 23 2013If the Moon's spin evolved from faster prograde rates, it could have been captured into a higher spin-orbit resonance than the current 1:1 resonance. At the current value of orbital eccentricity, the probability of capture into the 3:2 resonance is as ... More

On the weak and ergodic limit of the spectral shift functionNov 19 2009We discuss convergence properties of the spectral shift functions associated with a pair of Schrodinger operators with Dirichlet boundary conditions at the end points of a finite interval (0, r) as the length of interval approaches infinity.

No pseudosynchronous rotation for terrestrial planets and moonsSep 07 2012Jan 19 2013We reexamine the popular belief that a telluric planet or satellite on an eccentric orbit can, outside a spin-orbit resonance, be captured in a quasi-static tidal equilibrium called pseudosynchronous rotation. The existence of such configurations was ... More

Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 667CNov 19 2013We investigate the dynamical evolution of the potentially habitable super-earth GJ 667Cc in the multiple system of at least two exoplanets orbiting a nearby M dwarf, paying special attention to its spin-orbital state. The published radial velocities for ... More

Photometric and astrometric vagaries of the enigma star KIC 8462852Sep 13 2016Sep 26 2016We apply a PCA-based pre-whitening method to the entire collection of main Kepler mission long-cadence data for KIC 8462852 spanning four years. This technique removes the correlated variations of instrumental origin in both the detected light curves ... More

Tidal dissipation in a homogeneous spherical body. II. Three examples: Mercury, Io, and Kepler-10 bJun 09 2014Oct 08 2014In Efroimsky & Makarov (2014), we derived from the first principles a formula for the tidal heating rate in a tidally perturbed homogeneous sphere. We compared it with the formulae used in the literature, and pointed out the differences. Using this result, ... More

Tidal dissipation in a homogeneous spherical body. I. MethodsJun 09 2014Dec 21 2015A formula for the tidal dissipation rate in a spherical body is derived from first principles, to correct some mathematical inaccuracies found in the literature. The development is combined with the Darwin-Kaula formalism for tides. Our intermediate results ... More

Observations of red giants with suspected massive companionsFeb 08 2019Mar 21 2019Motivated by the existence of binary systems where a stellar-mass black hole is bound to a normal star, we selected four red giants with large radial velocity (RV) variation from the survey of SIM grid stars and monitored their RVs for several months. ... More

A lecture on Arithmetic Mirror Symmetry and Calabi-Yau manifoldsDec 03 1996Feb 11 1997We extend our variant of mirror symmetry for K3 surfaces \cite{GN3} and clarify its relation with mirror symmetry for Calabi-Yau manifolds. We introduce two classes (for the models A and B) of Calabi-Yau manifolds fibrated by K3 surfaces with some special ... More

Automorphic Forms and Lorentzian Kac-Moody Algebras. Part IINov 24 1996Feb 10 1997We give variants of lifting construction, which define new classes of modular forms on the Siegel upper half-space of complex dimension 3 with respect to the full paramodular groups (defining moduli of Abelian surfaces with arbitrary polarization). The ... More

The Igusa modular forms and ``the simplest'' Lorentzian Kac--Moody algebrasMar 13 1996We find automorphic corrections for the Lorentzian Kac--Moody algebras with the simplest generalized Cartan matrices of rank 3: A_{1,0} = 2 0 -1 0 2 -2 -1 -2 2 and A_{1,I} = 2 -2 -1 -2 2 -1 -1 -1 2 For A_{1,0} this correction is given by the Igusa Sp_4(Z)-modular ... More

Siegel automorphic form corrections of some Lorentzian Kac--Moody Lie algebrasApr 10 1995Oct 04 1995We find automorphic form corrections which are generalized Lorentzian Kac--Moody superalgebras without odd real simple roots (see R. Borcherds \cite{Bo1} -- \cite{Bo7}, V. Kac \cite{Ka1} -- \cite{Ka3}, R. Moody \cite{Mo} and \S~6 of this paper) for two ... More

Variability induced motion in Kepler dataMar 22 2016Variability induced motion (VIM) is an observable effect in simultaneous astrometric and photometric measurements caused by brightness variation in one of the components of a double source or blended image, which manifests itself as a strongly correlated ... More

Tidal Friction and Tidal Lagging. Applicability Limitations of a Popular Formula for the Tidal TorqueSep 07 2012Jan 19 2013Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning, and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly ... More

Forced libration of tidally synchronized planets and moonsNov 19 2015Tidal dissipation of kinetic energy, when it is strong enough, tends to synchronize the rotation of planets and moons with the mean orbital motion, or drive it into long-term stable spin-orbit resonances. As the orbital motion undergoes periodic acceleration ... More

Dynamical evolution and spin-orbit resonances of potentially habitable exoplanets. The case of GJ 581dAug 03 2012Jan 21 2013GJ 581d is a potentially habitable super-Earth in the multiple system of exoplanets orbiting a nearby M dwarf. We investigate this planet's long-term dynamics, with an emphasis on its probable final rotation states acquired via tidal interaction with ... More

Radial velocities and binarity of southern SIM grid starsOct 29 2014We present analysis of precision radial velocities (RV) of 1134 mostly red giant stars in the southern sky, selected as candidate astrometric grid objects for the Space Interferometry Mission (SIM). Only a few (typically, 2 or 3) spectroscopic observations ... More

Astrometric Effects of Secular AberrationAug 24 2005One of the main endeavors of fundamental astrometry is to establish a practical realization of an inertial reference frame anchored to celestial objects whose positions are defined in the barycentric coordinates of the solar system. The development of ... More

Double stars and astrometric uncertainties in Gaia DR1Apr 02 2017A significant number of double stars with separations up to 2.5 arcsec are present in the Gaia Data Release 1 astrometric catalogs. Limiting our analysis to a well-studied sample of 1124 doubles resolved by Hipparcos, provided with individual Tycho component ... More

Revealing companions to nearby stars with astrometric accelerationApr 18 2012A subset of 51 Hipparcos astrometric binaries among FG dwarfs within 67pc has been surveyed with the NICI adaptive optics system at Gemini-S, directly resolving for the first time 17 sub-arcsecond companions and 7 wider ones. Using these data together ... More

Unconstrained Astrometric Orbits for Hipparcos Stars with Stochastic SolutionsJun 13 2006A considerable number of astrometric binaries whose positions on the sky do not obey the standard model of mean position, parallax and linear proper motion, were observed by the Hipparcos satellite. Some of them remain non-discovered, and their observational ... More

Gravitational bending of light by planetary multipolesDec 04 2007General relativistic deflection of light by mass, dipole, and quadrupole moments of gravitational field of a moving massive planet in the Solar system is derived in the approximation of the linearized Einstein equations. All terms of order 1 microarcsecond ... More

Gravitational bending of light by planetary multipoles and its measurement with microarcsecond astronomical interferometersNov 11 2006Feb 08 2007General relativistic deflection of light by mass, dipole, and quadrupole moments of gravitational field of a moving massive planet in the Solar system is derived. All terms of order 1 microarcsecond are taken into account, parametrized, and classified ... More

Random matrix theory for low-frequency sound propagation in the ocean: a spectral statistics testMay 31 2017Problem of long-range sound propagation in the randomly-inhomogeneous deep ocean is considered. We examine a novel approach for modeling of wave propagation, developed by K.C.Hegewisch and S.Tomsovic. This approach relies on construction of a wavefield ... More

Mechanism of epitaxial self-assembly of Fe nanowedge islands on Mo(110)May 07 2004The deposition of ultrathin Fe films on the Mo(110) surface at elevated temperatures results in the formation of distinctive nanowedge islands supported on a pseudomorphic Fe layer. We propose a model explaining the growth mode of these wedge-shaped Fe ... More

Pattern formation in a two-dimensional two-species diffusion model with anisotropic nonlinear diffusivities: a lattice approachMay 23 2017Diffusion in a two-species 2D system has been simulated using a lattice approach. Rodlike particles were considered as linear $k$-mers of two mutually perpendicular orientations ($k_x$- and $k_y$-mers) on a square lattice. These $k_x$- and $k_y$-mers ... More

The origin of negative charging in amorphous Al$_2$O$_3$ films: The role of native defectsNov 01 2018Mar 04 2019Amorphous aluminum oxide Al$_2$O$_3$ (a-Al$_2$O$_3$) layers grown by various deposition techniques contain a significant density of negative charges. In spite of several experimental and theoretical studies, the origin of these charges still remains unclear. ... More

Highly Volcanic Exoplanets, Lava Worlds, and Magma Ocean Worlds: An Emerging Class of Dynamic Exoplanets of Significant Scientific PriorityApr 13 2018Highly volcanic exoplanets, which can be variously characterized as 'lava worlds', 'magma ocean worlds', or 'super-Ios' are high priority targets for investigation. The term 'lava world' may refer to any planet with extensive surface lava lakes, while ... More

Exoplanet Science Priorities from the Perspective of Internal and Surface Processes for Silicate and Ice Dominated WorldsApr 13 2018The geophysics of extrasolar planets is a scientific topic often regarded as standing largely beyond the reach of near-term observations. This reality in no way diminishes the central role of geophysical phenomena in shaping planetary outcomes, from formation, ... More

Micromagnetic Theory of Curvilinear Ferromagnetic ShellsApr 04 2019Here, we present a micromagnetic theory of curvilinear ferromagnets, which allows discovering novel fundamental physical effects which were amiss. In spite of the firm confidence for more than 70 years, we demonstrate that there is an intimate coupling ... More

The Worst Distortions of Astrometric Instruments and Orthonormal Models for Rectangular Fields of ViewOct 13 2011The non-orthogonality of algebraic polynomials of field coordinates traditionally used to model field-dependent corrections to astrometric measurements, gives rise to subtle adverse effects. In particular, certain field dependent perturbations in the ... More

UrHip Proper Motion CatalogSep 18 2015Proper motions are computed and collected in a catalog using the Hipparcos positions (epoch 1991.25) and URAT1 positions (epoch 2012.3 to 2014.6). The goal is to obtain a significant improvement on the proper motion accuracy of single stars in the northern ... More

Towards the ICRF3: astrometric comparison of the USNO 2016A VLBI solution with ICRF2 and Gaia DR1Apr 26 2018The VLBI USNO 2016A (U16A) solution is part of a work-in-progress effort by USNO towards the preparation of the ICRF3. Most of the astrometric improvement with respect to the ICRF2 is due to the re-observation of the VCS sources. Our objective in this ... More

The precious set of radio-optical reference frame objects in the light of Gaia DR2 dataNov 25 2018Feb 07 2019We investigate a sample of 3412 {\it International Celestial Reference Frame} (ICRF3) extragalactic radio-loud sources with accurate positions determined by VLBI in the S/X band, mostly active galactic nuclei (AGN) and quasars, which are cross-matched ... More

Quantum radiation from an evaporating non-singular black holeApr 10 2017In this paper we study quantum radiation from an evaporating spherically symmetric non-singular black hole. We used a modified Hayward metric for a description of a non-singular black hole. We assume that the mass parameter of this metric depends on the ... More

Quantum radiation from a sandwich black holeDec 16 2016Feb 07 2017We discuss quantum radiation of a massless scalar field from a spherically symmetric nonsingular black hole with finite lifetime. Namely, we discuss a sandwich black-hole model, where a black hole is originally created by a collapse of a null shell of ... More

On dissipative and non-unitary solutions to operator commutation relationsMar 11 2015We study the (generalized) semi-Weyl commutation relations $$ U_gAU_g^*=g(A) \quad \text{ on }\quad \Dom(A), $$ where $A$ is a densely defined operator and $G\ni g\mapsto U_g$ is a unitary representation of the subgroup $G$ of the affine group $\cG$, ... More

Spin-orbit evolution of Mercury revisitedJun 29 2013Aug 24 2014While it is accepted that the eccentricity of Mercury (0.206) favours entrapment into the 3:2 spin-orbit resonance, open is the question how and when the capture took place. A recent work by Makarov (2012) has demonstrated that trapping into this resonance ... More

Antisymmetric Tensor Fields, 4-Potentials and Indefinite MetricsFeb 18 2004We generalize the Stueckelberg formalism in the (1/2,1/2) representation of the Lorentz Group. Some relations to other modern-physics models are found.

(Modified) Fredholm Determinants for Operators with Matrix-Valued Semi-Separable Integral Kernels RevisitedDec 12 2003We revisit the computation of (2-modified) Fredholm determinants for operators with matrix-valued semi-separable integral kernels. The latter occur, for instance, in the form of Green's functions associated with closed ordinary differential operators ... More

The singularly continuous spectrum and non-closed invariant subspacesMar 05 2004Jul 28 2004Let $\mathbf{A}$ be a bounded self-adjoint operator on a separable Hilbert space $\mathfrak{H}$ and $\mathfrak{H}_0\subset\mathfrak{H}$ a closed invariant subspace of $\mathbf{A}$. Assuming that $\mathfrak{H}_0$ is of codimension 1, we study the variation ... More

Gibbs measures associated to the integrals of motion of the periodic derivative nonlinear Schrödinger equationFeb 20 2015Feb 01 2016We study the one dimensional periodic derivative nonlinear Schr\"odinger (DNLS) equation. This is known to be a completely integrable system, in the sense that there is an infinite sequence of formal integrals of motion $\int h_k$, $k\in \mathbb{Z}_{+}$. ... More

Astrometric evidence for a population of dislodged AGNDec 20 2016Jan 12 2017We investigate a sample of 2293 ICRF2 extragalactic radio-loud sources with accurate positions determined by VLBI, mostly active galactic nuclei (AGN) and quasars, which are cross-matched with optical sources in the first Gaia release (Gaia DR1). The ... More

The gravitational field of static p-branes in linearized ghost-free gravityFeb 26 2018Apr 05 2018We study the gravitational field of static p-branes in D-dimensional Minkowski space in the framework of linearized ghost-free (GF) gravity. The concrete models of GF gravity we consider are parametrized by the non-local form factors $\exp(-\Box/\mu^2)$ ... More

The Barut Second-Order Equation, Dynamical Invariants and InteractionsMar 06 2005The second-order equation in the (1/2,0)+(0,1/2) representation of the Lorentz group has been proposed by A. Barut in the beginning of the 70s. It permits to explain the mass splitting of leptons e,mu,tau. Recently, the interest has grown to this model ... More

QFT's With Action of Degree 3 and Higher and Degeneracy of TensorsMay 31 1997In this paper we develop a technique of computation of correlation functions in theories with action being cubic or higher degree form in terms of discriminants of corresponding tensors. These are analogues of formula $\int \exp (iT(x))dx\sim \det T^{-1/2}$ ... More

On Invariant TheoryDec 14 1995Jun 28 1997Here we develop a technique of computing the invariants of $n-$ary forms and systems of forms using the discriminants of corresponding multilinear forms built of their partial derivatives, which should be cosidered as analogues of classical discriminants ... More

Antisymmetric Tensor Fields, 4-Vector Fields, Indefinite Metrics and NormalizationNov 14 2007On the basis of our recent modifications of the Dirac formalism we generalize the Bargmann-Wigner formalism for higher spins to be compatible with other formalisms for bosons. Relations with dual electrodynamics, with the Ogievetskii-Polubarinov notoph ... More

The Structure and the Distance of Collinder 121 from Hipparcos and Photometry: Resolving the DiscrepancyAug 24 2007We present further arguments that the Hipparcos parallaxes for some of the clusters and associations represented in the Hipparcos catalog should be used with caution in the study of the Galactic structure. It has been already shown that the discrepancy ... More

Direct surface charging and alkali-metal doping for tuning the interlayer magnetic order in planar nanostructuresJul 13 2015The continuous reduction of magnetic units to ultra small length scales inspires efforts to look for a suitable means of controlling magnetic states. In this study we show two surface charge alteration techniques for tuning the interlayer exchange coupling ... More

Quantum Spin Holography with Surface State ElectronsApr 05 2012In a recent paper Moon and coworkers [C.R. Moon et al., Nature Nanotechnology 4, 167 (2009)] have shown that the single-atom limit for information storage density can be overcome by using the coherence of electrons in a two-dimensional electron gas to ... More

Gaugino Condensation with a Doubly Suppressed Gravitino MassApr 24 2008Supersymmetry breakdown via gaugino condensation in heterotic string theory can lead to models with a doubly suppressed gravitino mass. A TeV scale gravitino can emerge from a condensate as large as the grand unified scale. We analyze the properties of ... More

Ferromagnetic Mott State in Twisted Graphene Bilayers at the Magic AngleDec 06 2018Dec 10 2018We address the effective tight-binding Hamiltonian that describes the insulating Mott state of twisted graphene bilayers at a magic angle. In that configuration, twisted bilayers form a honeycomb superlattice of localized states, characterized by the ... More

Massive mimetic cosmologyFeb 21 2019We study the first cosmological implications of the mimetic theory of massive gravity recently proposed by Chamseddine and Mukhanov. This is a novel theory of ghost-free massive gravity which additionally contains a mimetic dark matter component. In an ... More

Calculus of conformal fields on a compact Riemann surfaceAug 24 2017Mar 11 2018We present analytical implementation of conformal field theory on a compact Riemann surface. We consider statistical fields constructed from background charge modifications of the Gaussian free field and derive Ward identities which represent the Lie ... More

Exact likelihood evaluations and foreground marginalization in low resolution WMAP dataMar 02 2004Apr 05 2004The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of the theoretical ... More

Interpolation of functional by integral continued C-fractionsJan 21 2018The functional interpolation problem on a continual set of nodes by an integral continued C-fraction is studied. The necessary and sufficient conditions for its solvability are found. As a particular case, the considered integral continued fraction contains ... More

Super-Exponentially Convergent Parallel Algorithm for a Fractional Eigenvalue Problem of Jacobi-TypeJun 27 2017A new algorithm for eigenvalue problems for the fractional Jacobi type ODE is proposed. The algorithm is based on piecewise approximation of the coefficients of the differential equation with subsequent recursive procedure adapted from some homotopy considerations. ... More

Align and Copy: UZH at SIGMORPHON 2017 Shared Task for Morphological ReinflectionJul 05 2017Jul 06 2017This paper presents the submissions by the University of Zurich to the SIGMORPHON 2017 shared task on morphological reinflection. The task is to predict the inflected form given a lemma and a set of morpho-syntactic features. We focus on neural network ... More

Double Poisson vertex algebras and non-commutative Hamiltonian equationsOct 13 2014May 23 2015We develop the formalism of double Poisson vertex algebras (local and non-local) aimed at the study of non-commutative Hamiltionan PDEs. This is a generalization of the theory of double Poisson algebras, developed by Van den Bergh, which is used in the ... More

Adler-Gelfand-Dickey approach to classical W-algebras within the theory of Poisson vertex algebrasJan 09 2014Jan 16 2014We put the Adler-Gelfand-Dickey approach to classical W-algebras in the framework of Poisson vertex algebras. We show how to recover the bi-Poisson structure of the KP hierarchy, together with its generalizations and reduction to the N-th KdV hierarchy, ... More

High-dimensional brain. A tool for encoding and rapid learning of memories by single neuronsOct 30 2017Jan 27 2018Codifying memories is one of the fundamental problems of modern Neuroscience. The functional mechanisms behind this phenomenon remain largely unknown. Experimental evidence suggests that some of the memory functions are performed by stratified brain structures ... More

Identification of 1.4 Million AGNs in the Mid-Infrared using WISE DataSep 24 2015We present an all-sky sample of ~ 1.4 million AGNs meeting a two color infrared photometric selection criteria for AGNs as applied to sources from the Wide-Field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution ... More

A new scheme of integrability for (bi)Hamiltonian PDEAug 11 2015Sep 05 2018We develop a new method for constructing integrable Hamiltonian hierarchies of Lax type equations, which combines the fractional powers technique of Gelfand and Dickey, and the classical Hamiltonian reduction technique of Drinfeld and Sokolov. The method ... More

Classical W-algebras and generalized Drinfeld-Sokolov bi-Hamiltonian systems within the theory of Poisson vertex algebrasJul 26 2012Aug 12 2013We provide a description of the Drinfeld-Sokolov Hamiltonian reduction for the construction of classical W-algebras within the framework of Poisson vertex algebras. In this context, the gauge group action on the phase space is translated in terms of (the ... More

Structure of classical (finite and affine) W-algebrasApr 02 2014First, we derive an explicit formula for the Poisson bracket of the classical finite W-algebra W^{fin}(g,f), the algebra of polynomial functions on the Slodowy slice associated to a simple Lie algebra g and its nilpotent element f. On the other hand, ... More

Neutron star merger GW170817 strongly constrains doubly coupled bigravityMar 26 2018Jun 14 2018We study the implications of the recent detection of gravitational waves emitted by a pair of merging neutron stars and their electromagnetic counterpart, events GW170817 and GRB170817A, on the viability of the doubly coupled bimetric models of cosmic ... More

Notes on Oscillator-Like Interactions of Various Spin Relativistic ParticlesMar 28 1994Mar 30 1994The equations for various spin particles with oscillator-like interactions are discussed in this talk. Contents: 1. Comment on "The Klein-Gordon Oscillator"; 2. The Dirac oscillator in quaternion form; 3. The Dirac-Dowker oscillator; 4. The Weinberg oscillator; ... More

X-Ray Sources in Multiple StarsAug 25 2009Luminous X-ray stars are very often found in visual double or multiple stars. Binaries with periods of a few days possess the highest degree of coronal X-ray activity among regular, non-relativistic stars because of their fast, tidally driven rotation. ... More

An efficient approach for solving stiff nonlinear boundary value problemsJan 17 2016Apr 19 2018A new method for solving stiff boundary value problems is described and compared to other known approaches using the Troesch's problem as a test example. The method is based on the general idea of alternate approximation of either the unknown function ... More

Zitterbewegung with spin-orbit coupled ultracold atoms in a fluctuating optical latticeDec 13 2015Feb 01 2016Dynamics of non-interacting ultracold atoms with artificial spin-orbit coupling is considered. Spin-orbit coupling is created using two moving optical lattices with orthogonal polarizations. Our main goal is to study influence of lattice noise on Rabi ... More

Question: Negative Group Delays and Action-at-a-DistanceFeb 17 1998We comment on the paper by M. W. Mitchell and R. Y. Chiao, ``Causality and negative group delay in a simple bandpass amplifier", Am. J. Phys. 66 (1), 14-19 (1998).

Automorphic Forms and Lorentzian Kac--Moody Algebras. Part IOct 31 1996Using the general method which was applied to prove finiteness of the set of hyperbolic generalized Cartan matrices of elliptic and parabolic type, we classify all symmetric (and twisted to symmetric) hyperbolic generalized Cartan matrices of elliptic ... More

K3 surfaces, Lorentzian Kac--Moody algebras and Mirror SymmetryOct 08 1995We consider the variant of Mirror Symmetry Conjecture for K3 surfaces which relates "geometry" of curves of a general member of a family of K3 with "algebraic functions" on the moduli of the mirror family. Lorentzian Kac--Moody algebras are involved in ... More

"Hybrid" Black HolesDec 30 2014We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. ... More

Resonant energy exchange in nonlinear oscillatory chains and Limiting Phase Trajectories: from small to large systemsMar 30 2009We present an adequate analytical approach to the description of nonlinear vibration with strong energy exchange between weakly coupled oscillators and oscillatory chains. The fundamental notion of the limiting phase trajectory (LPT) corresponding to ... More

The local stellar velocity field via vector spherical harmonicsMay 22 2007We analyze the local field of stellar tangential velocities for a sample of $42 339$ non-binary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism. We derive simple relations between the parameters of the classical linear ... More

A Lecture about classification of Lorentzian Kac-Moody algebras of the rank threeOct 31 2000This is the announcement and partly the review of our results about classification of Lorentzian Kac-Moody algebras of the rank three. One of our results gives the classification of Lorentzian Kac-Moody algebras with denominator identity functions which ... More

Stationary Large Amplitude Dynamics of the Finite Chain of Harmonically Coupled PendulumsMar 23 2016We present an analytical description of the large-amplitude stationary oscillations of the finite discrete system of harmonically-coupled pendulums without any restrictions to their amplitudes (excluding a vicinity of $\pi$). Although this model has numerous ... More

Rigidly rotating ZAMO surfaces in the Kerr spacetimeAug 27 2014A stationary observer in the Kerr spacetime has zero angular momentum if his/her angular velocity $\omega$ has a particular value, which depends on the position of the observer. Worldlines of such zero angular momentum observers (ZAMOs) with the same ... More

The TAN $2Θ$ Theorem for Indefinite Quadratic FormsJun 16 2010A version of the Davis-Kahan Tan $2\Theta$ theorem [SIAM J. Numer. Anal. \textbf{7} (1970), 1 -- 46] for not necessarily semibounded linear operators defined by quadratic forms is proven. This theorem generalizes a recent result by Motovilov and Selin ... More

A generalization of the $tan 2Θ$ TheoremFeb 03 2003Let $\mathbf{A}$ be a bounded self-adjoint operator on a separable Hilbert space $\mathfrak{H}$ and $\mathfrak{H}_0\subset\mathfrak{H}$ a closed invariant subspace of $\mathbf{A}$. Assuming that $\sup\spec(A_0)\leq \inf\spec(A_1)$, where $A_0$ and $A_1$ ... More

Perturbation of spectra and spectral subspacesJun 01 2003Jul 23 2007We consider the problem of variation of spectral subspaces for linear self-adjoint operators under off-diagonal perturbations. We prove a number of new optimal results on the shift of the spectrum and obtain (sharp) estimates on the norm of the difference ... More

Encoding Microreactors with Droplet Chains in MicrofluidicsNov 15 2018Droplet-based high throughput biomolecular screening and combinatorial synthesis entail a viable indexing strategy to be developed for the identification of each micro-reactor. Here, we propose a novel indexing scheme based on the generation of droplet ... More

Implementation vulnerabilities in general quantum cryptographyMay 17 2018Oct 24 2018Quantum cryptography is information-theoretically secure owing to its solid basis in quantum mechanics. However, generally, initial implementations with practical imperfections might open loopholes, allowing an eavesdropper to compromise the security ... More

An efficient approach for solving stiff nonlinear boundary value problemsJan 17 2016Feb 27 2016A new method for solving stiff boundary value problems is described and compared to other known approaches using the Troesch's problems as a test example. A c++ implementation of the proposed method is available at https://github.com/imathsoft/MathSoftDevelopment. ... More

Conductance of a Single-mode Electron Waveguide with Statistically Identical Rough BoundariesDec 10 1997Transport characteristics of pure narrow 2D-conductors, in which the electron scattering is caused by rough side boundaries, have been studied. The conductance of such strips is highly sensitive to the intercorrelation properties of inhomogeneities of ... More

Resonance accretion on the magnetized rotating neutron starMar 21 2001It is suggested that the accretion disk excites the eigen modes of Alfven oscillations of the magnetic field tubes the ends of which are frozen to the neutron star surface. The resonance takes place when the eigen Alfven frequency coincides with the difference ... More

Electron localization in two-dimensional surface-corrugated conductors: manifestation of competing scattering mechanismsMay 08 2001Transport properties of narrow two-dimensional conducting wires in which the electron scattering is caused by side edges' roughness have been studied. The method for calculating dynamic characteristics of such conductors is proposed which is based on ... More

Non-perturbative results for the spectrum of surface-disordered waveguidesJul 30 1998We calculated the spectrum of normal scalar waves in a planar waveguide with absolutely soft randomly rough boundaries beyond the perturbation theories in the roughness heights and slopes, basing on the exact boundary scattering potential. The spectrum ... More

Identification of organic molecules with a laboratory prototype based on the Laser Ablation-CosmOrbitrapApr 20 2019In the Solar System, extra-terrestrial organic molecules have been found on cometary primitive objects, on Titan and Enceladus icy moons and on Mars. Identification could be achieved for simple organic species by remote sensing based on spectroscopic ... More

Chaos-assisted formation of immiscible matter-wave solitons and self-stabilization in the binary discrete nonlinear Schrödinger equationDec 09 2015Binary discrete nonlinear Schr\"odinger equation is used to describe dynamics of two-species Bose-Einstein condensate loaded into an optical lattice. Linear inter-species coupling leads to Rabi transitions between the species. In the regime of strong ... More

Quantum ratchet driven by broadband perturbationSep 04 2013Oct 08 2013Motion of an atomic ensemble trapped into a deep optical lattice is considered. We propose a novel approach to construct an atomic ratchet by superimposing two additional lattices whose amplitudes are small and subjected to broadband modulation. The broadband ... More