Results for "V. Guarrera"

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Linear and non-linear coherent coupling in a Bell-Bloom magnetometerMar 13 2019Spin-exchange collisions in hot vapours are generally regarded as a decoherence mechanism. In contrast, we show that linear and non-linear spin-exchange coupling can lead to the generation of atomic coherence in a Bell-Bloom magnetometer. In particular, ... More
Microwave-dressed state-selective potentials for atom interferometryMar 09 2015We propose a novel and robust technique to realize a beam splitter for trapped Bose-Einstein condensates (BECs). The scheme relies on the possibility of producing different potentials simultaneously for two internal atomic states. The atoms are coherently ... More
Parametric amplification and noise-squeezing in room temperature atomic vapoursMar 01 2019We report on the use of parametric excitation to coherently manipulate the collective spin state of an atomic vapour at room temperature. Signatures of the parametric excitation are detected in the ground-state spin evolution. These include the excitation ... More
Towards a Bose-Glass of ultracold atoms in a disordered crystal of lightMar 24 2006Nov 13 2006Starting from one-dimensional Mott Insulators, we use a bichromatic optical lattice to add controlled disorder to an ideal optical crystal where bosonic atoms are pinned by repulsive interactions. Increasing disorder, we observe a broadening of the Mott ... More
Continuous Coupling of Ultracold Atoms to an Ionic Plasma via Rydberg ExcitationDec 21 2011We characterize the two-photon excitation of an ultracold gas of Rubidium atoms to Rydberg states analysing the induced atomic losses from an optical dipole trap. Extending the duration of the Rydberg excitation to several ms, the ground state atoms are ... More
Scanning electron microscopy of Rydberg-excited Bose-Einstein condensatesMar 07 2014We report on the realization of high resolution electron microscopy of Rydberg-excited ultracold atomic samples. The implementation of an ultraviolet laser system allows us to excite the atom, with a single-photon transition, to Rydberg states. By using ... More
Controlling the dynamics of an open many-body quantum system with localized dissipationDec 19 2012We experimentally investigate the action of a localized dissipative potential on a macroscopic matter wave, which we implement by shining an electron beam on an atomic Bose-Einstein condensate (BEC). We measure the losses induced by the dissipative potential ... More
Effect of interactions on the localization of a Bose-Einstein condensate in a quasi-periodic latticeNov 06 2006The transport properties of a Bose-Einstein condensate in a 1D incommensurate bichromatic lattice are investigated both theoretically and experimentally. We observe a blockage of the center of mass motion with low atom number, and a return of motion when ... More
Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguideJul 06 2005We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation ... More
Spatio-temporal Fermionization of Strongly Interacting 1D BosonsJan 24 2012Jul 19 2012Building on the recent experimental achievements obtained with scanning electron microscopy on ultracold atoms, we study one-dimensional Bose gases in the crossover between the weakly (quasi-condensate) and the strongly interacting (Tonks-Girardeau) regime. ... More
Noise correlation spectroscopy of the broken order of a Mott insulating phaseMar 13 2008We use a two-color lattice to break the homogeneous site occupation of an atomic Mott Insulator of bosonic 87Rb. We detect the disruption of the ordered Mott domains via noise correlation analysis of the atomic density distribution after time-of-flight. ... More
Holographic Fermi surfaces and bulk dipole couplingsFeb 18 2011Mar 14 2011Non-Fermi liquids can be studied using holographic duality. The low energy physics of a holographic Fermi surface is controlled by an emergent scale invariance. After reviewing these developments, we generalize the holographic calculation to include in ... More
Mesoscopic Rydberg-blockaded ensembles in the superatom regime and beyondJul 14 2014Feb 25 2016Controlling strongly interacting many-body systems enables the creation of tailored quantum matter, with properties transcending those based solely on single particle physics. Atomic ensembles which are optically driven to a Rydberg state provide many ... More
Localization by Dissipative Disorder: a Deterministic Approach to Position MeasurementsMar 09 2015We propose an approach to position measurements based on the hypothesis that the action of a position detector on a quantum system can be effectively described by a dissipative disordered potential. We show that such kind of potential is able, via the ... More
Heterotic Flux Vacua from Hybrid Linear ModelsFeb 25 2009We construct hybrid linear models in which the chiral anomaly of a gauged linear sigma model is canceled by the classical anomaly of a gauged WZW model. Semi-classically, this corresponds to fibering the WZW model over the naive target space of the sigma ... More
A cold-atom random laserJan 03 2013Conventional lasers make use of optical cavities to provide feedback to gain media. Conversely, mirrorless lasers can be built by using disordered structures to induce multiple scattering, which increases the effective path length in the gain medium and ... More
Observation of local temporal correlations in trapped quantum gasesMay 24 2011We measure the temporal pair correlation function $g^{(2)}(\tau)$ of a trapped gas of bosons above and below the critical temperature for Bose-Einstein condensation. The measurement is performed {\it in situ} using a local, time-resolved single-atom sensitive ... More
Cross-dimensional phase transition from an array of 1D Luttinger liquids to a 3D Bose-Einstein condensateOct 07 2014We study the thermodynamic properties of a 2D array of coupled one-dimensional Bose gases. The system is realized with ultracold bosonic atoms loaded in the potential tubes of a two-dimensional optical lattice. For negligible coupling strength, each tube ... More
Thermodynamics of Strongly Correlated One-Dimensional Bose GasesApr 16 2013We investigate the thermodynamics of one-dimensional Bose gases in the strongly correlated regime. To this end, we prepare ensembles of independent 1D Bose gases in a two-dimensional optical lattice and perform high-resolution in situ imaging of the column-integrated ... More
Double resonant processes in $χ^{(2)}$ nonlinear periodic mediaAug 07 2000In a one-dimensional periodic nonlinear $\chi^{(2)}$ medium, by choosing a proper material and geometrical parameters of the structure, it is possible to obtain two matching conditions for simultaneous generation of second and third harmonics. This leads ... More
Neutron Diffraction and Optics of a Noncentrosymmetric Crystal. New Feasibility of a Search for Neutron EDMApr 25 2005May 03 2005Recently strong electric fields (up to 10^9 V/cm) have been discovered, which affect the neutrons moving in noncentrosymmetric crystals. Such fields allow new polarization phenomena in neutron diffraction and optics and provide, for instance, a new feasibility ... More
A remark on the Dixmier ConjectureNov 30 2018The Dixmier Conjecture says that every endomorphism of the (first) Weyl algebra $A_1$ (over a field of characteristic zero) is an automorphism, i.e., if $PQ-QP=1$ for some $P, Q \in A_1$ then $A_1 = K \langle P, Q \rangle$. The Weyl algebra $A_1$ is a ... More
Morita invariance of the filter dimension and of the inequality of BernsteinOct 29 2006It is proved that the filter dimenion is Morita invariant. A direct consequence of this fact is the Morita invariance of the inequality of Bernstein: if an algebra $A$ is Morita equivalent to the ring $\CD (X)$ of differential operators on a smooth irreducible ... More
On some basic properties of Leibniz algebrasFeb 14 2013Mar 01 2013This paper gives an overview of some basic properties of Leibniz algebras. Some of the results were known earlier, but in the article they are accompanied by new simple proofs. Some of the results are new. The article can be viewed as a digest or a mini-manual ... More
Namioka spaces and strongly Baire spacesJan 22 2016A notion of strongly Baire space is introduced. Its definition is a transfinite development of some equivalent reformulation of the Baire space definition. It is shown that every strongly Baire space is a Namioka space and every $\beta-\sigma$-unfavorable ... More
Dixmier's Problem 5 for the Weyl AlgebraMar 02 2004A proof is given to the Dixmier's 5'th problem for the Weyl algebra.
Criteria for a ring to have a left Noetherian left quotient ringAug 16 2015Two criteria are given for a ring to have a left Noetherian left quotient ring (this was an open problem since 70's). It is proved that each such ring has only finitely many maximal left denominator sets.
Polarons: from single polaron to short scale phase separationNov 07 2006Short review of the phase separation in the system of charged polarons.
Three-page embeddings of singular knotsSep 19 2003Sep 20 2003Construction of a semigroup with 15 generators and 84 relations is given. The center of this semigroup is in one-to-one correspondence with the set of all isotopy classes of non-oriented singular knots (links with finitely many double intersections in ... More
Two scales in neutrino physicsJun 28 2011The problem of neutrino mass origin is considered on the phenomenological level. The assumption is made that the neutrino mass values depend on two dominant contributions with their characteristic scales. The neutrino mass values as well as the values ... More
Fundamental interactions in quantum phase space specified by extra dimensional constantsNov 14 2007Dec 18 2007A generalized algebra of quantum observables, depending on extra dimensional constants, is considered. Some limiting forms of the algebra are investigated and their possible applications to the descriptions of interactions of fundamental particles are ... More
Mass spectra of excited meson states consisting of u-, d-quarks and antiquarksApr 11 2005Mass spectra of excited meson states consisting of u-, d-quarks and antiquarks with I = 1 are considered. The comparison between the existing experimental data and the mass values evaluated with phenomenological formulae is carried out. Problems of identification ... More
Open Clusters IC 4665 and Cr 359 and a Probable Birthplace of the Pulsar PSR B1929+10Oct 01 2008Based on the epicyclic approximation, we have simulated the motion of the young open star clusters IC 4665 and Collinder 359. The separation between the cluster centers is shown to have been minimal 7 Myr ago, 36 pc. We have established a close evolutionary ... More
Hamiltonian anomalies of bound states in QEDMay 13 2012The Bound State in QED is described in systematic way by means of nonlocal irreducible representations of the nonhomogeneous Poincare group and Dirac's method of quantization. As an example of application of this method we calculate triangle diagram $Para-Positronium ... More
Chiral Phenomenological Relations between Rates of Rare Radiative Decay of Kaon to Pion and leptons and the meson FormfactorsApr 09 2010Oct 08 2010In framework of the chiral perturbation theory we obtain the phenomenological relations between decay branches of rare radiative kaon to pion and leptons $K^+ \to \pi^+ l^+ l^-$ and $K^0_S \to \pi^0 l^+ l^-$ and meson form factors. The comparison of these ... More
On the two body problem in the classical electrodynamicsJan 12 2015Jan 14 2015In this paper we propose an approach to the problem of two body motion in classical electrodynamics that takes into account the electromagnetic radiation and the radiation reaction forces. The resulting differential equations are solved numerically.
Surface plasmon excitation by a quantum oscillatorNov 08 2009Dec 03 2009Surface waves in a thin uniform metal film are described in terms of quantum electrodynamics.The interaction of surface waves with a quantum oscillator is discussed in the dipole approximation. The increase in the spontaneous emission rate of the excited ... More
Viscous dark fluidOct 01 2007Oct 15 2007The unified dark energy and dark matter model within the framework of a model of a continuous medium with bulk viscosity (dark fluid) is considered. It is supposed that the bulk viscosity coefficient is an arbitrary function of the Hubble parameter. The ... More
Letters of a Bi-Rationalist: VII. Ordered terminationJul 31 2006Nov 21 2006To construct a resulting model in LMMP is sufficient to prove existence of log flips and their termination for certain sequences. We prove that LMMP in dimension $d-1$ and termination of terminal log flips in dimension $d$ imply, for any log pair of dimension ... More
CPT Groups of Spinor Fields in de Sitter and Anti-de Sitter SpacesJan 30 2014Apr 02 2015$CPT$ groups for spinor fields in de Sitter and anti-de Sitter spaces are defined in the framework of automorphism groups of Clifford algebras. It is shown that de Sitter spaces with mutually opposite signatures correspond to Clifford algebras with different ... More
Cyclic structures of Cliffordian supergroups and particle representations of Spin_+(1,3)Jul 26 2012Supergroups are defined in the framework of $\dZ_2$-graded Clifford algebras over the fields of real and complex numbers, respectively. It is shown that cyclic structures of complex and real supergroups are defined by Brauer-Wall groups related with the ... More
Group averaging for de Sitter free fields in terms of hyperspherical functionsFeb 18 2010Jun 03 2011We study the convergence of inner products of free fields over the homogeneous spaces of the de Sitter group and show that the convergence of inner products in the of $N$-particle states is defined by the asymptotic behavior of hypergeometric functions. ... More
On integrable discretization of the inhomogeneous Ablowitz-Ladik modelOct 13 1999An integrable discretization of the inhomogeneous Ablowitz-Ladik model with a linear force is introduced. Conditions on parameters of the discretization which are necessary for reproducing Bloch oscillations are obtained. In particular, it is shown that ... More
Time-resolved spectroscopy and photometry of the dwarf nova FS Aurigae in quiescenceJun 21 2001Oct 26 2001We present results of non-simultaneous time-resolved photometric and spectroscopic observations of the little-studied dwarf nova FS Aur in quiescence. The spectrum of FS Aur shows strong and broad emission lines of hydrogen and HeI, and of weaker HeII ... More
The group ${\rm K}_1(\mS_n)$ of the algebra of one-sided inverses of a polynomial algebraMay 19 2010May 03 2013The algebra $\mS_n$ of one-sided inverses of a polynomial algebra $P_n$ in $n$ variables is obtained from $P_n$ by adding commuting, {\em left} (but not two-sided) inverses of the canonical generators of the algebra $P_n$. The algebra $\mS_n$ is a noncommutative, ... More
Electroweak Phase Transition in Strong Magnetic Fields in the Standard Model of Elementary ParticlesDec 08 1999The electroweak phase transition in the magnetic and hypermagnetic fields is studied in the Standard Model on the base of investigation of symmetry behaviour within the consistent effective potential of the scalar and magnetic fields at finite temperature. ... More
Extinctions and distances of dark clouds from UGRIJHK photometry of red clump giants: the North America and Pelican nebulae complexNov 25 2009A possibility of applying 2MASS J, H, Ks, IPHAS r, i and MegaCam u, g photometry of red giants for determining distances to dark clouds is investigated. Red clump giants with a small admixture of G5-K1 and M2-M3 stars of the giant branch can be isolated ... More
Young Stars in the Camelopardalis Dust and Molecular Clouds. III. the GL 490 RegionMar 17 2008Using the infrared photometry data extracted from the 2MASS, IRAS and MSX databases, 50 suspected young stellar objects (YSOs) are selected from about 37500 infrared objects in the 3x3 deg area with the center at Galactic longitude 142.5 deg and latitude ... More
Young stars and clouds in CamelopardalisNov 18 2008Star formation in the Local spiral arm in the direction of the Galactic longitudes 132--158 deg is reviewed. Recent star-forming activity in this Milky Way direction is evidenced by the presence here of the Cam OB1 association and dense dust and molecular ... More
Surface modes and photonic modes in Casimir calculations for a compact cylinderDec 20 2007A rigorous formulation of the problem of calculating the electromagnetic vacuum energy of an infinite dielectric cylinder is discussed. It is shown that the physically relevant spectrum of electromagnetic excitations includes the surface modes and photonic ... More
On the model of the relativistic particle with curvature and torsionMay 29 1993Two integrals along the world trajectory of its curvature and torsion are added to the standard action for the point-like spinless relativistic particle. Since here the three-dimensional space-time is considered at the beginning, the torsion of the world ... More
On squaring the primary constraints in a generalized Hamiltonian dynamicsSep 02 1993Consideration of the model of the relativistic particle with curvature and torsion in the three-dimensional space-time shows that the squaring of the primary constraints entails a wrong result. The complete set of the Hamiltonian constraints arising here ... More
The nature of the Vela X-ray "jet"Dec 02 1999The nature of the Vela X-ray "jet", recently discovered by Markwardt & \"Ogelman (1995), is examined. It is suggested that the "jet" arises along the interface of domelike deformations of the Rayleigh-Taylor unstable shell of the Vela supernova remnant; ... More
Supernova remnant S147 and its associated neutron star(s)Aug 27 2005Apr 08 2006The supernova remnant S147 harbors the pulsar PSR J0538+2817 whose characteristic age is more than an order of magnitude greater than the kinematic age of the system (inferred from the angular offset of the pulsar from the geometric center of the supernova ... More
Light amplification and scattering by clusters made of small active particles: the local perturbation approachApr 04 2013Dec 14 2014The light amplification by finite active media is used extensively in modern optics applications. In this paper the light amplification and scattering by cluster of small particles is studied analytically and numerically with the help of the local perturbation ... More
On Justification of Gibbs DistributionApr 04 2005The paper develop a new approach to the justification of Gibbs canonical distribution for Hamiltonian systems with finite number of degrees of freedom. It uses the condition of nonintegrability of the ensemble of weak interacting Hamiltonian systems.
Canonical Gibbs distribution and thermodynamics of mechanical systems with a finite number of degrees of freedomApr 04 2005Traditional derivation of Gibbs canonical distribution and the justification of thermodynamics are based on the assumption concerning an isoenergetic ergodicity of a system of $n$ weakly interacting identical subsystems and passage to the limit $n\to\infty$. ... More
Billiards, invariant measures, and equilibrium thermodynamics. IIMar 09 2005The kinetics of collisionless continuous medium is studied in a bounded region on a curved manifold. We have assumed that in statistical equilibrium, the probability distribution density depends only on the total energy. It is shown that in this case, ... More
Description of moduli space of projective structures via fat graphsDec 25 1993Feb 01 1994We give an elementary explicit construction of cell decomposition of the moduli space of projective structures on a two dimensional surface analogous to the decomposition of Penner/Strebel for moduli space of complex structures. The relations between ... More
Lepton mass and mixing in a Neutrino Mass Model based on $S_4$ flavor symmetryMar 12 2016We study a neutrino mass model based on $S_4$ flavor symmetry which accommodates lepton mass, mixing with non-zero $\theta_{13}$ and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and ... More
Current status of the Dynamical Casimir EffectApr 19 2010Oct 24 2010This is a brief review of different aspects of the so-called Dynamical Casimir Effect and the proposals aimed at its possible experimental realizations. A rough classification of these proposals is given and important theoretical problems are pointed ... More
Resonance Photon Generation in a Vibrating CavityOct 26 1998The problem of photon creation from vacuum due to the nonstationary Casimir effect in an ideal one-dimensional Fabry--Perot cavity with vibrating walls is solved in the resonance case, when the frequency of vibrations is close to the frequency of some ... More
Quantum spectrum of black holesSep 12 2005Oct 03 2005The black hole as the thermodynamical system in equilibrium possesses the periodicity of motion in imaginary time, that allows us to formulate the quasi-classical rule of quantization. The rule yields the equidistant spectrum for the entropy of non-rotating ... More
Radial geodesics as a microscopic origin of black hole entropy. I: Confined under the Schwarzschild horizonDec 19 2004Feb 03 2005Causal radial geodesics with a positive interval in the Schwarzschild metric include a subset of trajectories completely confined under a horizon, which compose a thermal statistical ensemble with the Hawking-Gibbons temperature. The Bekenstein--Hawking ... More
Quintessence and black holesOct 14 2002Dec 20 2002We present new static spherically-symmetric exact solutions of Einstein equations with the quintessential matter surrounding a black hole charged or not as well as for the case without the black hole. A condition of additivity and linearity in the energy-momentum ... More
Quantum gravity as a consistent local field theoryJul 05 2002Sep 09 2002We show that the Einstein-Hilbert action for the gravitational field can be obtained as a linear low-energy approximation for the dynamical massless fields in the theory with the lagrangian quadratic in the gauge field strength-tensor of spin connection ... More
Model for three generations of fermionsJun 30 1998Jul 31 1998A model is constructed for a chiral abelian gauge-interaction of fermions and a potential of three higgses, so that the potential possesses a discrete symmetry of the vacuum state, which provides the introduction of three generations for the fermions. ... More
Estimate of $α_s(m_Z)$ in sum rules for bottomoniumOct 25 1996The value of $\alpha_s(m_Z)=0.106\pm 0.005$ is obtained in a scheme of sum rules for the leptonic constants of the vector $nS$-levels in the heavy $(\bar b b)$-quarkonium.
Semileptonic $B\to D^{(*)}lν$ decays, the slope of Isgur-Wise function and $|V_{bc}|$ value in potential quark modelSep 19 1994The modification of the naive potential model of the heavy meson is considered on the basis of the single-time prescription for the quark-meson form factor and the covariant choice of the quatk relative momentum. The application of the model to the description ... More
Thermodynamical instability of black holesAug 07 2012In contrast to Hawking radiation of black hole with a given spacetime structure, we consider a competitive transition due to a heat transfer from a hotter inner horizon to a colder outer horizon of Kerr black hole, that results in a stable thermodynamical ... More
Isospin breaking in scalar and pseudoscalar channels of radiative $J/ψ$-decaysFeb 06 2007Feb 08 2007In the framework of simple assumption on factorizing a mixing of vector state with isoscalar components in effective amplitudes of isospin breaking caused by the electromagnetic quark current, a branching fraction of radiative $J/\psi\to a_0$ transition ... More
Leptonic constant of pseudoscalar B_c mesonApr 02 2003Apr 06 2003We calculate the leptonic constant for the ground pseudoscalar state of B_c meson in the framework of QCD-motivated potential model taking into account the two-loop anomalous dimension for the heavy quark current in the nonrelativistic QCD as matched ... More
Exclusive Decays and Lifetime of B_c Meson in QCD sum rulesNov 04 2002Feb 07 2003We summarize theoretical calculations of B_c decays and lifetime in the framework of QCD sum rules and compare the results with the estimates by the methods of Operator Product Expansion in the inverse heavy quark masses as well as of potential quark ... More
Evolution of flat universe with a cosmological term in modified Relativistic Theory of Gravitation as a scalar-tensor extension of General RelativityJun 01 2001Apr 04 2002We consider the dynamics of tensor and scalar gravitational fields in the Relativistic Theory of Gravitation with the Minkowskian vacuum metric and generalize the formulation to the massless graviton. The potential of scalar field is determined in the ... More
Model for two generations of fermionsAug 01 1997Feb 27 1998In the model with the spontaneous breaking of chiral gauge symmetry, the vacuum structure for the pair of Higgs fields can provide the introduction of two generations of fermions. The mixing matrix of charged currents is determined.
Modified renormalonJul 05 1995In the framework of renormalon consideration in the approximation of a large number of quark flavours, a role of the anomalous dependence of gluon propagator on the scale $\mu$ is shown.
Masses of $nS$-wave Heavy Quarkonium Levels from QCD Sum RulesJul 26 1994Using a specific scheme of the QCD sum rules, one derives an universal formula for the mass differences for the $nS$-levels of heavy qiarkonium. This relation does not depend on the flavours of the heavy quarks, composing the quarkonium, and it is in ... More
The ${\rm Jacobian Conjecture}_{2n}$ implies the ${\rm Dixmier Problem}_n$Dec 12 2005Using the author's inversion formula for automorphisms of the Weyl algebras with polynomial coefficients and the bound on its degree a slightly shorter (algebraic) proof is given of the result of A. Belov-Kanel and M. Kontsevich that the Jacobian Conjecture ... More
Enhanced effect of temporal variation of the fine structure constant and strong interaction in 229ThApr 24 2006Nov 21 2011The relative effects of variation of the fine structure constant alpha=e^2/hc and dimensionless strong interaction parameter m_q/Lambda_{QCD} are enhanced 5-6 orders of magnitude in very narrow ultraviolet transition between the ground and first excited ... More
Limits on temporal variation of quark masses and strong interaction from atomic clock experimentsFeb 06 2003We perform calculations of the dependence of nuclear magnetic moments on quark masses and obtain limits on the variation of m_q/Lambda_{QCD} from recent atomic clock experiments with hyperfine transitions in H, Rb, Cs, Hg+ and optical transtion in Hg+. ... More
Slow long-range decay of bound Hartree-Fock orbitals and enhancement of the exchange interaction and tunnelingAug 15 2008Exchange interaction strongly influences the long-range behaviour of localised electron orbitals. It violates the oscillation theorem (creates extra nodes) and produces a power-law decay instead of the usual exponential decrease at large distances. For ... More
The System of Molecular Clouds in the Gould BeltJul 01 2016Based on high-latitude molecular clouds with highly accurate distance estimates taken from the literature, we have redetermined the parameters of their spatial orientation. This system can be approximated by a 350x235x140 pc ellipsoid inclined by the ... More
Mobilisation readiness state and the frequency structure of heart rate variabilityMay 05 2010A number of studies showed association of mental status with heart rate variability. This work discovered a feature of frequency structure of heart rate variability that is associated with mental readiness. In three independent groups of 64, 39, and 19 ... More
Namioka spaces and topological gamesDec 23 2015We introduce a class of $\beta-v$-unfavorable spaces, which contains some known classes of $\beta$-unfavorable spaces for topological games of Choquet type. It is proved that every $\beta-v$-unfavorable space $X$ is a Namioka space, that is for any compact ... More
Some extensions of the class of $k$-convex bodiesSep 22 2008We study relations of some classes of $k$-convex, $k$-visible bodies in Euclidean spaces. We introduce and study \textrm{circular projections} in normed linear spaces and classes of bodies related with families of such maps, in particular, \textrm{$k$-circular ... More
On Disjointness of Mixing Rank One ActionsSep 04 2011For flows the rank is an invariant by linear change of time. But what we can say about isomorphisms? It seems that in case of mixing flows this problem is the most difficult. However the known technique of joinings provides non-isomorphism for mixing ... More
On Local Rank, Joinings and Asymptotic Properties of Measure-Preserving ActionsMay 31 2012The note contains a collection of facts and observations around locally rank one actions as well as constructions connected with some results by T.Downarowicz, A.Katok, J.King, F.Parreau, A.A.Prikhodko, E.Roy, J.Serafin, J-P.Thouvenot et al.
On Mixing Constructions with Algebraic SpacersAug 06 2011Aug 09 2011We recall a proof of the mixing for almost all Ornstein's stochastic rank one constructions, replace stochastic spacers by special algebraic ones and prove the mixing in this new situation.
Simple Spectrum for Tensor Products of Mixing Map PowersJul 24 2011We prove the existence of a mixing rank one map $T$ such that the product $T\otimes T^2\otimes T^3\otimes...$ has simple spectrum. This result is used in S.V. Thikhonov's proof of the existence of mixing transformation with homogeneous spectrum of multiplicity ... More
Spectral multiplicity for powers of weakly mixing automorphismsFeb 15 2011We study the behavior of maximal multiplicities $mm (R^n)$ for the powers of a weakly mixing automorphism $R$. For some special infinite set $A$ we show the existence of a weakly mixing rank-one automorphism $R$ such that $mm (R^n)=n$ and $mm(R^{n+1}) ... More
Exclusive C=+ charmonium production in $e^+ e^- \to H+γ$ at B-factories within light cone formalismJun 30 2010In this paper the cross sections of the processes $e^+ e^- \to H+\gamma, H=\eta_c, \eta_c', \chi_{c0}, \chi_{c1}, \chi_{c2}$ are calculated. The calculation is carried out at the leading twist approximation of light cone formalism. Within this approach ... More
Vertex corrections to the mean-field electrical conductivity in strongly disordered electron systemsSep 27 2012Mean-field theory of non-interacting disordered electron systems is widely and successfully used to describe equilibrium properties of alloys in the whole range of disorder strengths. It, however, fails to take into account effects of quantum coherence ... More
The generalized Weyl Poisson algebras and their Poisson simplicity criterionFeb 02 2019A new class of Poisson algebras, the class of {\em generalized Weyl Poisson algebras}, is introduced. It can be seen as Poisson algebra analogue of generalized Weyl algebras or as giving a Poisson structure to (certain) generalized Weyl algebras. A Poisson ... More
Gravitational collapse as the source of gamma-ray burstsMay 21 2008If the threshold for $e^{-}e^{+}$ pair production depends on an angle between photon momenta, and if the $\gamma$-rays are collimated right in gamma-ray burst (GRB) source then another solution of the compactness problem is possible. The list of basic ... More
The gamma-ray bursts and core-collapse supernovae - global star forming rate peaks at large redshiftsOct 29 2013This is a brief review on the first Gamma-Ray Bursts (GRB) optical identifications - GRB host galaxies and Star Forming Rate (SFR) at relatively small redshifts (z), on the metallicities of GRB hosts, the similarities and differences between GRB hosts ... More
On S. Mazur's problems 8 and 88 from the Scottish BookMar 24 2007The paper discusses Problems 8 and 88 posed by Stanislaw Mazur in the Scottish Book. It turns out that negative solutions to both problems are immediate consequences of the results of Section 5 of my paper "Estimates of functions of power bounded operators ... More
Factorization of monomorphisms of a polynomial algebra in one variableJan 07 2007Let $K[x]$ be a polynomial algebra in a variable $x$ over a commutative $\Q$-algebra $K$, and $\G'$ be the monoid of $K$-algebra monomorphisms of $K[x]$ of the type $\s : x\mapsto x+\l_2x^2+... +\l_nx^n$, $\l_i\in K$, $\l_n$ is a unit of $K$. It is proved ... More
The group of automorphisms of the algebra of one-sided inverses of a polynomial algebraMar 17 2009Jun 15 2009The algebra $\mS_n$ in the title is obtained from a polynomial algebra $P_n$ in $n$ variables by adding commuting, {\em left} (but not two-sided) inverses of the canonical generators of $P_n$. Ignoring non-Noetherian property, the algebra $\mS_n$ belongs ... More
Universal Coverings of the Orthogonal GroupsMay 13 2004Universal coverings of the orthogonal groups and their extensions are studied in terms of Clifford-Lipschitz groups. An algebraic description of basic discrete symmetries (space inversion $P$, time reversal $T$, charge conjugation $C$ and their combinations ... More
The groups of automorphisms of the Witt $W_n$ and Virasoro Lie algebrasApr 13 2013The groups of automorphisms of the Witt $W_n$ and Virasoro Lie algebras are found.