Results for "Andrei Tokovinin"

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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
New orbits based on speckle interferometry at SOARAug 03 2016Orbits of 55 visual binary stars are computed using recent speckle interferometry data from the SOAR telescope: 33 first-time orbits and 22 revisions of previous orbit calculations. The orbital periods range from 1.4 to 370 years, the quality of orbits ... More
Kappa Fornaci, a triple radio-starJan 07 2013Bright and nearby (22pc) solar-type dwarf Kappa Fornaci (HIP 11072) is a triple system. The close pair of M-type dwarfs Ba,Bb with a tentative period of 3.7 days moves around the main component A on a 26-year orbit. The mass of the "dark companion" Ba+Bb ... More
Low-mass visual companions to nearby G-dwarfsNov 09 2010Complete census of wide visual companions to nearby G-dwarf stars can be achieved by selecting candidates from the 2MASS Point-Source Catalog and checking their status by second-epoch imaging. Such data are obtained for 124 candidates with separations ... More
The triple system Zeta AquariiAug 30 2016Zeta Aquarii is a bright and nearby (28 pc) triple star with a 26-year astrometric subsystem. Almost a half of the outer 540-year visual orbit has been covered in 238 years of its observations. Both inner and outer orbits are revised here taking into ... More
From binaries to multiples II: hierarchical multiplicity of F and G dwarfsJan 27 2014Statistics of hierarchical multiplicity among solar-type dwarfs are studied using the distance-limited sample of 4847 targets presented in the accompanying Paper I. Known facts about binaries (multiplicity fraction 0.46, log-normal period distribution ... More
Speckle interferometry and orbits of "fast" visual binariesJun 08 2012Results of speckle observations at the 4.1-m SOAR telescope in 2012 (158 measures of 121 systems, 27 non-resolutions) are reported. The aim is to follow fast orbital motion of recently discovered or neglected close binaries and sub-systems. Here 8 previously ... More
Spectroscopic subsystems in nearby wide binariesNov 04 2015Radial velocity (RV) monitoring of solar-type visual binaries has been conducted at the CTIO/SMARTS 1.5-m telescope to study short-period systems. Data reduction is described, mean and individual RVs of 163 observed objects are given. New spectroscopic ... More
Orbits of four young triple-lined multiple systemsApr 21 2016Each of the nearby triple systems HIP 7601, 13498, 23824, and 113597 (HD 10800, 18198, 35877, 217389) consists of solar-type dwarfs with comparable masses, where all three components are resolved spectrally, while the outer pairs are resolved both visually ... More
Orbits of subsystems in four hierarchical multiple starsApr 21 2016Seven spectroscopic orbits in nearby solar-type multiple stars are presented. The primary of the chromospherically active star HIP 9642 is a 4.8-day double-lined pair; the outer 420-yr visual orbit is updated, but remains poorly constrained. HIP 12780 ... More
Imaging survey of subsystems in secondary components to nearby southern dwarfsJul 22 2014Aug 01 2014To improve the statistics of hierarchical multiplicity, secondary components of wide nearby binaries with solar-type primaries were surveyed at the SOAR telescope for evaluating the frequency of subsystems. Images of 17 faint secondaries were obtained ... More
From binaries to multiples I: Data on F and G dwarfs within 67 pc of the SunJan 27 2014Data on the multiplicity of F- and G-type dwarf stars within 67pc of the Sun are presented. This distance-limited sample based on the Hipparcos catalog contains 4847 primary stars (targets) with 0.5<V-I_C<0.8 and is >90% complete. There are 2196 known ... More
Atmospheric time constant with MASS and FADEJan 17 2011The approximate nature of the adaptive-optics time constant measurements with MASS is examined. The calibration coefficient C derived from numerical simulations of polychromatic scintillation shows dependence on the height of the turbulence layer, wind ... More
Yes, multi-periodic dwarfs in Upper Scorpius are binariesAug 07 2018We found that multi-periodic low-mass stars discovered by Kepler K2 in the Upper Scorpius association are close binaries with typical separations of the order of 10 au and large mass ratios. These stars were surveyed by speckle interferometry at the SOAR ... More
Wide companions to Hipparcos stars within 67 pc of the SunAug 02 2012A catalog of common-proper-motion (CPM) companions to stars within 67 pc of the Sun is constructed based on the SUPERBLINK proper-motion survey. It contains 1392 CPM pairs with angular separations 30" < \rho < 1800", relative proper motion between the ... More
Eccentricity distribution of wide binariesDec 01 2015A sample of 477 solar-type binaries within 67pc with projected separations larger than 50AU is studied by a new statistical method. Speed and direction of the relative motion are determined from the short observed arcs or known orbits, and their joint ... More
New binaries in the epsilon Cha associationSep 15 2017We present Adaptive Optics-aided speckle observations of 47 young stars in the $\epsilon$ Cha association, made at the 4-m Southern Astrophysical Research Telescope in the $I$-band. We resolved 10 new binary pairs, 5 previously known binaries and two ... More
Speckle interferometry of secondary components in nearby visual binariesAug 23 2016Statistical characterization of secondary subsystems in binaries helps to distinguish between various scenarios of multiple-star formation. The DSSI speckle instrument was used at the Gemini-N telescope for several hours in 2015 July to probe binarity ... More
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
SOAR Adaptive Optics Observations of the Globular Cluster NGC6496Apr 16 2013We present high-quality BVRI photometric data in the field of globular cluster NGC 6496 obtained with the SOAR Telescope Adaptive Module (SAM). Our observations were collected as part of the ongoing SAM commissioning. The distance modulus and cluster ... More
Companions to nearby stars with astrometric acceleration. IIApr 30 2013Hipparcos astrometric binaries were observed with the NICI adaptive optics system at Gemini-S, completing the work of Paper I (Tokovinin et al. 2012). Among the 65 F, G, K dwarfs within 67pc of the Sun studied here, we resolve 18 new sub-arcsecond companions, ... More
SRAO: optical design and the dual-knife-edge WFSAug 01 2016The Southern Robotic Adaptive Optics (SRAO) instrument will bring the proven high-efficiency capabilities of Robo-AO to the Southern-Hemisphere, providing the unique capability to image with high-angular-resolution thousands of targets per year across ... More
Sub-systems in nearby solar-type wide binariesJun 07 2010We conducted a deep survey of resolved sub-systems among wide binaries with solar-type components within 67 pc from the Sun. Images of 61 stars in the K and H bands were obtained with the NICI adaptive-optics instrument on the 8-m Gemini-South telescope. ... More
The unusual quadruple system HD 91962 with a "planetary" architectureApr 24 2015The young nearby solar-type star HD 91962 is a rare quadruple system where three companions revolve around the main component with periods of 170.3 days, 8.85 years, and 205 years. The two outer orbits are nearly co-planar, and all orbits have small eccentricities. ... 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
Speckle interferometry at the Blanco and SOAR telescopes in 2008 and 2009Nov 30 2009The results of speckle interferometric measurements of binary and multiple stars conducted in 2008 and 2009 at the Blanco and SOAR 4-m telescopes in Chile are presented. A total of 1898 measurements of 1189 resolved pairs or sub-systems and 394 observations ... More
Speckle interferometry at SOAR in 2012 and 2013Mar 19 2014We report the results of speckle runs at the 4.1-m Southern Astronomical Research (SOAR) telescope in 2012 and 2013. A total of 586 objects were observed. We give 699 measurements of 487 resolved binaries and upper detection limits for 112 unresolved ... More
Spectroscopic orbits of nearby starsApr 13 2019We observed stars with variable radial velocities to determine their spectroscopic orbits. Velocities of 132 targets taken over a time span reaching 30 years are presented. They were measured with the correlation radial velocity spectrometers (1913 velocities) ... More
Speckle interferometry at SOAR in 2015Mar 24 2016The results of speckle interferometric observations at the SOAR telescope in 2015 are given, totalling 1303 measurements of 924 resolved binary and multiple stars and non-resolutions of 260 targets. The separations range from 12 mas to 3.37" (median 0.17"); ... More
Continued Kinematic and Photometric Investigations of Hierarchical Solar-Type Multiple Star SystemsJan 20 2017We observed 15 of the solar-type binaries within 67 pc of the Sun previously observed by the Robo-AO system in the visible, with the PHARO near-IR camera and the PALM-3000 adaptive optics system on the 5 m Hale telescope. The physical status of the binaries ... More
Speckle interferometry at SOAR in 2014Jun 18 2015The results of speckle interferometric observations at the SOAR telescope in 2014 are given. A total of 1641 observations were taken, yielding 1636 measurements of 1218 resolved binary and multiple stars and 577 non-resolutions of 441 targets. We resolved ... More
SOAR Adaptive Module (SAM): seeing improvement with a UV laserAug 19 2016The adaptive module of the 4.1-m SOAR telescope, SAM, corrects ground-layer turbulence using a UV laser guide star. It has been commissioned in 2013 and it is in regular science operation since 2014. SAM works with the CCD imager covering a 3' field or ... More
Speckle interferometry at SOAR in 2016 and 2017Apr 27 2018The results of speckle interferometric observations at the 4.1 m SOAR telescope in 2016 and 2017 are given, totaling 2483 measurements of 1570 resolved pairs and 609 non-resolutions. We describe briefly recent changes in the instrument and observing method ... More
Observations of Hierarchical Solar-Type Multiple Star SystemsSep 02 2015Twenty multiple stellar systems with solar-type primaries were observed at high angular resolution using the PALM-3000 adaptive optics system at the 5 m Hale telescope. The goal was to complement the knowledge of hierarchical multiplicity in the solar ... More
Comparative statistics and origin of triple and quadruple starsJun 19 2008The statistics of catalogued quadruple stars consisting of two binaries (hierarchy 2+2) is studied in comparison with triple stars, with respective sample sizes of 81 and 724. Seven representative quadruple systems are discussed in greater detail. The ... More
Know the Star, Know the Planet. III. Discovery of Late-Type Companions to Two Exoplanet Host StarsMar 04 2015We discuss two multiple star systems that host known exoplanets: HD 2638 and 30 Ari B. Adaptive optics imagery revealed an additional stellar companion to both stars. We collected multi-epoch images of the systems with Robo-AO and the PALM-3000 adaptive ... More
Multiple stars: designation, catalogues, statisticsJan 23 2006Discussion of the designation of multiple-star components leads to a conclusion that, apart from components, we need to designate systems and centers-of-mass. The hierarchy is coded then by simple links to parent. This system is adopted in the multiple ... More
CHIRON - A Fiber Fed Spectrometer for Precise Radial VelocitiesSep 16 2013The CHIRON optical high-resolution echelle spectrometer was commissioned at the 1.5m telescope at CTIO in 2011. The instrument was designed for high throughput and stability, with the goal of monitoring radial velocities of bright stars with high precision ... More
Atmospheric coherence times in interferometry: definition and measurementOct 06 2006Current and future ground-based interferometers require knowledge of the atmospheric time constant t_0, but this parameter has diverse definitions. Moreover, adequate techniques for monitoring t_0 still have to be implemented. We derive a new formula ... More
The mass ratio distribution of B-type visual binaries in the Sco OB2 associationSep 25 2001The sample of 115 B-type stars in Sco OB2 association is examined for existence of visual companions with ADONIS near-infrared adaptive optics system and coronograph in J and K bands. Practically all components in the separation range 0.3"-6" (45-900 ... More
Donut: measuring optical aberrations from a single extra-focal imageJun 15 2006We propose a practical method to calculate Zernike aberrations from analysis of a single long-exposure defocused stellar image. It consists in fitting the aberration coefficients and seeing blur directly to a realistic image binned into detector pixels. ... More
Multiplicity in Early Stellar EvolutionMar 08 2014Observations from optical to centimeter wavelengths have demonstrated that multiple systems of two or more bodies is the norm at all stellar evolutionary stages. Multiple systems are widely agreed to result from the collapse and fragmentation of cloud ... More
Compact jets as probes for sub-parsec scale regions in AGNJun 25 2007Compact relativistic jets in active galactic nuclei offer an effective tool for investigating the physics of nuclear regions in galaxies. The emission properties, dynamics, and evolution of jets in AGN are closely connected to the characteristics of the ... More
Axiomatic Method and Category TheorySep 25 2012Lawvere's axiomatization of topos theory and Voevodsky's axiomatization of heigher homotopy theory exemplify a new way of axiomatic theory building, which goes beyond the classical Hibert-style Axiomatic Method. The new notion of Axiomatic Method that ... More
On non-markovian nature of stock tradingMar 18 2004Using a relationship between the moments of the probability distribution of times between the two consecutive trades (intertrade time distribution) and the moments of the distribution of a daily number of trades we show, that the underlying point process ... More
Geometry of optimal control problems and Hamiltonian systemsJun 10 2005These notes are based on the mini-course given in June 2004 in Cetraro, Italy, in the frame of a C.I.M.E. school. Of course, they contain much more material that I could present in the 6 hours course. The main goal is to give an idea of the general variational ... More
About the Mechanism of Volcanic EruptionsAug 02 2012A new approach to the volcanic eruption theory is proposed. It is based on a simple physical mechanism of the imbalance in the system "magma-crust-fluid". This mechanism helps to explain from unified positions the different types of volcanic eruptions. ... More
About the Mechanism of Geyser EruptionApr 06 2012Essentially new physical mechanism of geyser eruption based on instability in "water-vapor" system is proposed. Necessary and sufficient conditions of eruptions are received. For group of Kamchatka geysers a good accordance of theoretical model with empirical ... More
Lectures on Inflationary CosmologyOct 12 1994A general overview of the history and present status of inflationary cosmology is given. Recent developments discussed in this paper include the hybrid inflation scenario, the theory of reheating, and the theory of inflating tolopogical defects. We also ... More
Inflation, Quantum Cosmology and the Anthropic PrincipleNov 07 2002Nov 08 2002Anthropic principle can help us to understand many properties of our world. However, for a long time this principle seemed too metaphysical and many scientists were ashamed to use it in their research. I describe here a justification of the weak anthropic ... More
Inflation and String CosmologyJul 20 2001Inflationary theory is already 20 years old, and it is impossible to describe all of its versions and implications in a short talk. I will concentrate on several subjects which I believe to be most important. First of all, I will give a brief review of ... More
On periodic solutions of a Hamilton-Jacobi equation with periodic forcingJun 23 1999Feb 09 2001We prove that a Hamilton-Jacobi equation in 1D with periodic forcing has a set of generalized solutions such that each solution is a sum of linear and continuous periodic functions; we also give a condition of uniqueness of this solution in terms of Aubry-Mather ... More
Moduli spaces of PU(2)-monopolesFeb 07 1997Nov 12 2013The goal of this article was the S^1-equivariant transversality-problem and the compactification-problem for the moduli spaces of (perturbed) PU(2)-monopoles. A substantially improved version entitled "Moduli spaces of PU(2)-monopoles (revised version)" ... More
Non-abelian Seiberg-Witten theory and projectively stable pairsSep 26 1996Jun 02 1997We introduce the concept of Spin^G-structure in a SO-bundle, where $G\subset U(V)$ is a compact Lie group containing $-id_V$. We study and classify $Spin^G(4)$-structures on 4-manifolds, we introduce the G-Monopole equations associated with a $Spin^G$-structure. ... More
Vaxjo Interpretation of Wave Function: 2012Oct 07 2012We discuss the problem of interpretation of the wave function. The latest version of the V\"axj\"o interpretation is presented. It differs essentially from the original V\"axj\"o interpretation (2001). The main distinguishing feature of the present V\"axj\"o ... More
Quantum-like model of processing of information in the brain based on classical electromagnetic fieldNov 28 2010We propose a model of quantum-like (QL) processing of mental information. This model is based on quantum information theory. However, in contrast to models of "quantum physical brain" reducing mental activity (at least at the highest level) to quantum ... More
Design of an Experiment to Test Quantum Probabilistic Behavior of the Financial marketFeb 11 2009The recent crash demonstrated (once again) that the description of the financial market by present financial mathematics cannot be considered as totally satisfactory. We remind that nowadays financial mathematics is heavily based on the use of random ... More
Quantum mechanics for military officersSep 17 2006We present a trivial probabilistic illustration for representation of quantum mechanics as an algorithm for approximative calculation of averages.
Prequantum classical statistical model with infinite dimensional phase-space-2: complex representation of symplectic phase-space modelMay 31 2005We show that QM can be represented as a natural projection of a classical statistical model on the phase space $\Omega= H\times H,$ where $H$ is the real Hilbert space. Statistical states are given by Gaussian measures on $\Omega$ having zero mean value ... More
Probabilistic foundations of quantum mechanics and quantum informationSep 08 2003We discuss foundation of quantum mechanics (interpretations, superposition, principle of complementarity, locality, hidden variables) and quantum information theory.
No "No-Go"Aug 29 2003In spite of the very common opinion we show that QM is not complete and that it is possible to create prequantum models providing finer description of physical reality than QM. There exists (at least in theoretical models) dispersion free states and the ... More
Fundamental Principle for Quantum TheoryApr 02 2002Mar 06 2003We propose the principle, the law of statistical balance for basic physical observables, which specifies quantum statistical theory among all other statistical theories of measurements. It seems that this principle might play in quantum theory the role ... More
Classical and quantum mechanics on information spaces with applications to cognitive, psychological, social and anomalous phenomenaMar 04 2000We use the system of p-adic numbers for the description of information processes. Basic objects of our models are so called transformers of information, basic processes are information processes, the statistics are information statistics (thus we present ... More
Measurement problem: from de Broglie to theory of classical random fields interacting with threshold detectorsDec 31 2012The quantum measurement problem as was formulated by von Neumann in 1933 can be solved by going beyond the operational quantum formalism. In our "prequantum model" quantum systems are symbolic representations of classical random fields. The Schr\"odinger's ... More
Born's rule from statistical mechanics of classical fields: from hitting times to quantum probabilitiesDec 01 2012We show that quantum probabilities can be derived from statistical mechanics of classical fields. We consider Brownian motion in the space of fields and show that such a random field interacting with threshold type detectors produces clicks at random ... More
Classical and quantum randomness and the financial marketApr 22 2007We analyze complexity of financial (and general economic) processes by comparing classical and quantum-like models for randomness. Our analysis implies that it might be that a quantum-like probabilistic description is more natural for financial market ... More
Quantum mechanics as an approximation of statistical mechanics for classical fieldsJun 03 2005Oct 03 2006We show that, in spite of a rather common opinion, quantum mechanics can be represented as an approximation of classical statistical mechanics. The approximation under consideration is based on the ordinary Taylor expansion of physical variables. The ... More
EPR-Bohm experiment, interference of probabilities, imprecision of timeFeb 10 2004May 13 2004We demonstrate that the EPR-Bohm probabilities can be easily obtained in the classical (but contextual) probabilistic framework by using the formula of interference of probabilities. From this point of view the EPR-Bell experiment is just an experiment ... More
Contextualist viewpoint to Greenberger-Horne-Zeilinger paradoxSep 08 2003We present probabilistic analysis of the Greenberger-Horne-Zeilinger (GHZ) scheme in the contextualist framework, namely under the assumption that distributions of hidden variables depend on settings of measurement devices. On one hand, we found classes ... More
Quantum theory: Reconsideration of foundationsFeb 10 2003The purpose of the conference (the fourth in the series of Vaxjo conferences) was to bring together scientists (physicists, mathematicians and philosophers) who are interested in foundations of quantum physics. An emphasis was made on both theory and ... More
Contextual viewpoint to quantum stochasticsDec 10 2001We study the role of context, complex of physical conditions, in quantum as well as classical experiments. It is shown that by taking into account contextual dependence of experimental probabilities we can derive the quantum rule for the addition of probabilities ... More
Quantum statistics via perturbation effects of preparation proceduresMar 13 2001We study the following problem: Is it possible to explain the quantum interference of probabilities in the purely corpuscular model for elementary particles? We demonstrate that (by taking into account perturbation effects of measurement and preparation ... More
Virtual Compton Scattering on the Proton at High s and Low tAug 12 1996Virtual Compton Scattering (VCS) at low transferred momenta to the proton ($t$) and sufficiently high c.m. energies ($s$) may be used to a) study $Q^2$--dependence of leading $t$--channel exchanges and b) look for onset of scaling behavior with increasing ... More
Heterotic compactifications and nearly-Kahler manifoldsSep 01 2004Sep 10 2004We propose that under certain conditions heterotic string compactifications on half-flat and nearly-Kahler manifolds are equivalent. Based on this correspondence we argue that the moduli space of the nearly-Kahler manifolds under discussion consists only ... More
Associative triples and Yang-Baxter equationMar 08 2000Feb 11 2002We introduce triples of associative algebras as a tool for building solutions to the Yang-Baxter equation. It turns out that the class of R-matrices thus obtained is related to a Hecke-like condition, which is formulated for associative algebras with ... More
Nonspherical Giant Gravitons and Matrix TheoryAug 10 2002Apr 05 2003We consider the plane wave limit of the nonspherical giant gravitons. We compute the Poisson brackets of the coordinate functions and find a nonlinear algebra. We show that this algebra solves the supersymmetry conditions of the matrix model. This is ... More
Giant Gravitons from Holomorphic SurfacesOct 24 2000We introduce a class of supersymmetric cycles in spacetimes of the form AdS times a sphere or $T^{1,1}$ which can be considered as generalizations of the giant gravitons. Branes wrapped on these cycles preserve $1\over 2$, $1\over 4$ or $1\over 8$ of ... More
Anomalous dimension and local chargesNov 19 2004Sep 20 2005AdS space is the universal covering of a hyperboloid. We consider the action of the deck transformations on a classical string worldsheet in $AdS_5\times S^5$. We argue that these transformations are generated by an infinite linear combination of the ... More
Special contact Wilson loopsNov 24 2002Dec 05 2002Wilson loops in ${\cal N}=4$ supersymmetric Yang-Mills theory correspond at strong coupling to extremal surfaces in $AdS_5$. We study a class of extremal surfaces known as special Legendrian submanifolds. The "hemisphere" corresponding to the circular ... More
Polarization puzzle in B->phi K* and other B->VV at BABARSep 29 2004With a sample of about 227 million BB pairs recorded with the BABAR detector we perform a full angular analysis of the decay B0->phi K*0(892). Ten measurements include polarization, phases, and five CP asymmetries. We also observe the decay B0->phi K*0(1430). ... More
How the first generations of luminous baryons established the X-ray and UV backgroundsJan 21 2011The first generations of astrophysical objects made a substantial impact on our Universe with their radiation. X-rays from the first sources, with large mean free paths, likely quickly heated the intergalactic medium (IGM). The second generation of 21cm ... More
Propagation and interaction of extremely short electromagnetic pulses in non-linear mediaDec 25 2000Propagation of the extremely short electromagnetic pulse in non-linear dielectric media without the slowly varying envelope approximation is discussed. The models under consideration take into account both resonant and not-resonant excitations of non-linear ... More
Holomorphic Currents and Duality in N=1 Supersymmetric TheoriesSep 12 2003Sep 30 2003Twisted supersymmetric theories on a product of two Riemann surfaces possess non-local holomorphic currents in a BRST cohomology. The holomorphic currents act as vector fields on the chiral ring. The OPE's of these currents are invariant under the renormalization ... More
Realization of $W_{1+\infty}$ and Virasoro Algebras in Supersymmetric Theories on Four ManifoldsJun 23 1994Jul 18 1994We demonstrate that a supersymmetric theory twisted on a K\"ahler four manifold $M=\Sigma_1 \times \Sigma_2 ,$ where $\Sigma_{1,2}$ are 2D Riemann surfaces, possesses a "left-moving" conformal stress tensor on $\Sigma_1$ ($\Sigma_2$) in the BRST cohomology. ... More
A precision measurement of the muon decay parameter deltaApr 14 2011The muon decay parameter delta characterizes momentum dependence of the parity-violating muon decay asymmetry. A new measurement of delta has been performed using the first physics data recorded by the TWIST experiment at TRIUMF. The obtained value, delta=0.74964+-0.00066(stat.)+-0.00112(syst.), ... More
Gravitational waves and large field inflationNov 30 2016According to the famous Lyth bound, one can confirm large field inflation by finding tensor modes with sufficiently large tensor-to-scalar ratio $r$. Here we will try to answer two related questions: Is it possible to rule out all large field inflationary ... More
Massey products in mapping toriOct 04 2016Let $\phi: M\to M$ be a diffeomorphism of a $C^\infty$ compact connected manifold, and $X$ its mapping torus. There is a natural fibration $p:X\to S^1$, denote by $\xi\in H^1(X, \mathbb{Z})$ the corresponding cohomology class. Let $\lambda\in \mathbb{Z}^*$. ... More
A virtual fundamental class construction for the moduli space of torus equivariant morphismsSep 22 2014May 09 2015Let X be a smooth projective variety with the action of the n dimensional torus. The article describes the moduli space of torus equivariant morphisms from stable toric varieties into X as the inverse limit of the GIT quotients of X and their flips when ... More
On Constructive Axiomatic MethodAug 14 2014Mar 26 2015In this last version of the paper one may find a critical overview of some recent philosophical literature on Axiomatic Method and Genetic Method.
On higher spin Uq(sl_2)-invariant R-matricesDec 23 2004Feb 28 2005The spectral decomposition of regular Uq(sl_2)-invariant solutions of the Yang-Baxter equation is studied. An algorithm for finding all possible solutions of spin s is developed. It also allows to reconstruct the R-matrix from a given nearest neighbour ... More
Massey products in mapping toriOct 04 2016Dec 20 2016Let $\phi: M\to M$ be a diffeomorphism of a $C^\infty$ compact connected manifold, and $X$ its mapping torus. There is a natural fibration $p:X\to S^1$, denote by $\xi\in H^1(X, \mathbb{Z})$ the corresponding cohomology class. Let $\lambda\in \mathbb{Z}^*$. ... More
Littlewood-Richardson semigroupsApr 30 1997This note is an extended abstract of my talk at the workshop on Representation Theory and Symmetric Functions, MSRI, April 14, 1997. We discuss the problem of finding an explicit description of the semigroup $LR_r$ of triples of partitions of length $\leq ... More
Violation of the Bell's type inequalities as a local expression of incompatibilityFeb 19 2019By filtering out the philosophic component we can be said that the EPR-paper was directed against the straightforward interpretation of the Heisenberg's uncertainty principle or more generally the Bohr's complementarity principle. The latter expresses ... More
Geometric quantization and mirror symmetryFeb 04 1999After the appearance of my preprint [T3] (Special Lagrangian geometry and slightly deformed algebraic geometry (spLag and sdAG), Warwick preprint 22/1998, alg-geom/9806006, 54 pp.). I received an e-mail from Cumrun Vafa, who recognized that the subject ... More
Special Langrangian geometry and slightly deformed algebraic geometry (spLag and sdAG)Jun 02 1998The special geometry of calibrated cycles, closely related to mirror symmetry among Calabi--Yau 3-folds, is itself a real form of a new subject, which we call slightly deformed algebraic geometry. On the other hand, both of these geometries are parallel ... More
The pseudo-effective cone of a non-Kählerian surface and applicationsApr 23 2007Jun 30 2007We describe the positive cone and the pseudo-effective cone of a non-K\"ahlerian surface. We use these results for two types of applications: - Describe the set $\sigma(X)$ of possible total Ricci scalars associated with Gauduchon metrics of fixed volume ... More
Derived Categories of Twisted Sheaves on Elliptic ThreefoldsDec 11 2000Mar 28 2001We construct an equivalence between the derived category of sheaves on an elliptic threefold without a section and a derived category of twisted sheaves (modules over an Azumaya algebra) on any small resolution of its relative Jacobian.
Did Lobachevsky Have A Model Of His "imaginary Geometry"?Aug 11 2010The invention of non-Euclidean geometries is often seen through the optics of Hilbertian formal axiomatic method developed later in the 19th century. However such an anachronistic approach fails to provide a sound reading of Lobachevsky's geometrical ... More
Vertex operators of ghost number three in Type IIB supergravityJan 15 2014Oct 25 2015We study the cohomology of the massless BRST complex of the Type IIB pure spinor superstring in flat space. In particular, we find that the cohomology at the ghost number three is nontrivial and transforms in the same representation of the supersymmetry ... More
Quiver Grassmannians and their Euler characteristics: Oberwolfach talk, May 2010Jun 04 2010This is an extended abstract of my talk at the Oberwolfach Workshop "Interactions between Algebraic Geometry and Noncommutative Algebra" (May 10 - 14, 2010). We present some properties of quiver Grassmannians and examples of explicit computations of their ... More