Results for "Nikolai Lauk"

total 1365took 0.11s
A number-state filter for pulses of lightDec 27 2015Mar 15 2016We present a detailed theoretical analysis of a Fock-state filter based on the photon-number dependent group delay in cavity induced transparency proposed in Phys. Rev. Lett. 105, 013601 (2010). We derive a general expression for the propagation velocity ... More
Towards long-distance quantum networks with superconducting processors and optical linksDec 20 2018We design a quantum repeater architecture, necessary for long distance quantum networks, using the recently proposed microwave cat state qubits, formed and manipulated via interaction between a superconducting nonlinear element and a microwave cavity. ... More
Fidelity of photon propagation in electromagnetically induced transparency in the presence of four-wave mixingApr 08 2013Jun 20 2013We study the effects of the four-wave mixing (4WM) in a quantum memory scheme based on electromagnetically induced transparency (EIT). We treat the problem of field propagation on the quantum mechanical level, which allows us to calculate the fidelity ... More
Towards room temperature indistinguishable single-photon sources using ultra-small mode volume cavities and solid-state emittersOct 10 2017Efficient sources of indistinguishable single photons that can operate at room temperature would be highly beneficial for many applications in quantum technology. We show that the implementation of such sources is a realistic goal using solid-state emitters ... More
Feasibility of efficient room-temperature solid-state sources of indistinguishable single photons using ultrasmall mode volume cavitiesOct 10 2017May 16 2018Highly efficient sources of indistinguishable single photons that can operate at room temperature would be very beneficial for many applications in quantum technology. We show that the implementation of such sources is a realistic goal using solid-state ... More
Interfacing Superconducting Qubits and Telecom Photons via a Rare-Earth Doped CrystalFeb 21 2014Jul 25 2014We propose a scheme to couple short single photon pulses to superconducting qubits. An optical photon is first absorbed into an inhomogeneously broadened rare-earth doped crystal using controlled reversible inhomogeneous broadening. The optical excitation ... More
Cross-spectral analysis of physiological tremor and muscle activity. I. Theory and application to unsynchronized EMGMay 08 1998We investigate the relationship between the extensor electromyogram (EMG) and tremor time series in physiological hand tremor by cross-spectral analysis. Special attention is directed to the phase spectrum and the effects of observational noise. We calculate ... More
Interfacing microwave qubits and optical photons via spin ensemblesJan 23 2015A protocol is discussed which allows one to realize a transducer for single photons between the optical and the microwave frequency range. The transducer is a spin ensemble, where the individual emitters possess both an optical and a magnetic-dipole transition. ... More
Electron Spin Coherences in Rare-Earth Optically Excited States for Microwave to Optical Quantum TransducersFeb 09 2018Efficient and reversible optical to microwave coherent transducers are required to enable entanglement transfer between superconducting qubits and light for quantum networks. Rare-earth-doped crystals that possess narrow optical and spin transitions are ... More
Electron Spin Coherences in Rare-Earth Optically Excited States for Microwave to Optical Quantum TransducersFeb 09 2018Feb 16 2018Efficient and reversible optical to microwave coherent transducers are required to enable entanglement transfer between superconducting qubits and light for quantum networks. Rare-earth-doped crystals that possess narrow optical and spin transitions are ... More
Quantum repeaters with individual rare-earth ions at telecommunication wavelengthsDec 14 2017Dec 18 2017We present a quantum repeater scheme that is based on individual Erbium and Europium ions. Erbium ions are attractive because they emit photons at telecommunication wavelength, while Europium ions offer exceptional spin coherence for long-term storage. ... More
Anomalous Quark Chromomagnetic Moment and Single-Spin AsymmetriesAug 22 2013Dec 26 2013We discuss a nonperturbative mechanism for the single-spin asymmetries (SSA) in the strong interaction. This mechanism is based on the existence of a large anomalous quark chromomagnetic moment (AQCM) induced by the nontrivial topological structure of ... More
The symmetrized polydisc cannot be exhausted by domains biholomorphic to convex domainsJul 09 2005We prove that the symmetrized polydisc cannot be exhausted by domains biholomorphic to convex domains.
On sampling theorem with sparse decimated samplesMay 02 2016Nov 20 2016The classical sampling Nyquist-Shannon-Kotelnikov theorem states that a band-limited continuous time function is uniquely defined by infinite two-sided sampling series taken with a sufficient frequency. The paper shows that these band-limited functions ... More
On the delayed stochastic integration and continuity in the Hurst parameterOct 05 2015Nov 02 2015We consider an approach to stochastic integration with respect to fractional Brownian motion with the Hurst parameter H>1/2 in the framework based on usual integral sums. We suggest a integral defined for delayed processes; this is why we call it delayed ... More
Methods of tropical optimization in rating alternatives based on pairwise comparisonsAug 09 2016We apply methods of tropical optimization to handle problems of rating alternatives on the basis of the log-Chebyshev approximation of pairwise comparison matrices. We derive a direct solution in a closed form, and investigate the obtained solution when ... More
QCD in beauty decays: successes and puzzlesJun 08 2004The status of the heavy quark expansion for inclusive B decays is briefly reviewed from the perspective of confronting theory with data and of extracting the heavy quark parameters. A good agreement between properly applied theory and new precision data ... More
A "BPS expansion" for B and D mesonsNov 30 2003We analyze consequences of the approximation \mu_\pi^2 -\mu_G^2 << \mu_\pi^2 (a `BPS' limit) for B and D mesons. It is shown that neglecting perturbative effects many power corrections would vanish to all orders in 1/m_Q, in particular those violating ... More
A recursive equations based representation for the $G/G/m$ queueOct 22 2012New recursive equations designed for the G/G/m queue are presented. These equations describe the queue in terms of recursions for the arrival and departure times of customers, and involve only the operations of maximum, minimum and addition.
On causal extrapolation of sequences with applications to forecastingAug 16 2012Feb 07 2018The paper suggests a method of extrapolation of notion of one-sided semi-infinite sequences representing traces of two-sided band-limited sequences; this features ensure uniqueness of this extrapolation and possibility to use this for forecasting. This ... More
On causal band-limited mean square approximationNov 29 2011Aug 10 2012We study causal dynamic approximation of non-bandlimited processes by band-limited processes such that a part of the historical path of the underlying process is approximated in $L_2$-norm by the trace of a band-limited process. This allows to cover the ... More
On identity theorem for real functionsNov 04 2009Identity theorem for analytic complex functions says that a function is uniquely defined by its values on a set that contains a density point. The paper presents sufficient conditions for classes of real analytic functions that ensures similar property. ... More
On recovering parabolic diffusions from their time-averagesSep 07 2016Mar 27 2017The paper study a possibility to recover a parabolic diffusion from its time-average when the values at the initial time are unknown. This problem can be reformulated as a new boundary value problem where a Cauchy condition is replaced by a prescribed ... More
On prescribed change of profile for solutions of parabolic equationsMay 08 2011Parabolic equations with homogeneous Dirichlet conditions on the boundary are studied in a setting where the solutions are required to have a prescribed change of the profile in fixed time, instead of a Cauchy condition. It is shown that this problem ... More
Causal band-limitness and predictability criterions for one-sided sequencesAug 25 2014Sep 23 2014The paper studies frequency characteristics and predictability of real sequences, i.e., discrete time processes in deterministic setting. We consider band-limitness and predictability of one-sided sequences. We establish predictability of some classes ... More
Sub-ideal causal smoothing filters for real sequencesNov 27 2014Jul 04 2015The paper considers causal smoothing of the real sequences, i.e.,discrete time processes in a deterministic setting. A family of causal linear time-invariant filters is suggested. These filters approximate the gain decay for some non-causal smoothing ... More
Spectrum degeneracy for functions on branching lines and impact on extrapolation and samplingMay 17 2017Oct 21 2018The paper studies functions defined on continuous branching lines connected into a system. A notion of spectrum degeneracy for these functions is introduced. This degeneracy is based on the properties of the Fourier transforms for processes representing ... More
Real and complex k-planes in convex hypersurfacesAug 23 2012It is shown that that the rank of the second fundamental form (resp. the Levi form) of a $\mathcal C^2$-smooth convex hypersurface $M$ in $\Bbb R^{n+1}$ (resp. $\Bbb C^{n+1}$) does not exceed an integer constant $k<n$ near a point $p\in M,$ then through ... More
Optimal solution of investment problems via linear parabolic equations generated by Kalman filterApr 29 2008We consider optimal investment problems for a diffusion market model with non-observable random drifts that evolve as an Ito's process. Admissible strategies do not use direct observations of the market parameters, but rather use historical stock prices. ... More
Form-factors of the finite quantum XY-chainDec 22 2009Mar 31 2011Explicit factorized formulas for the matrix elements (form-factors) of the spin operators \sigma^x and \sigma^y between the eigenvectors of the Hamiltonian of the finite quantum periodic XY-chain in a transverse field were derived. The derivation is based ... More
A new algebraic solution to multidimensional minimax location problems with Chebyshev distanceOct 17 2012Both unconstrained and constrained minimax single facility location problems are considered in multidimensional space with Chebyshev distance. A new solution approach is proposed within the framework of idempotent algebra to reduce the problems to solving ... More
The 2D Zakharov-Kuznetsov-Burgers equation on a stripApr 17 2014An initial-boundary value problem for the 2D Zakharov-Kuznetsov-Burgers equation posed on a channel-type strip was considered. The existence and uniqueness results for regular and weak solutions in weighted spaces as well as exponential decay of small ... More
Kawahara-Burgers equation on a stripAug 25 2014An initial-boundary value problem for the 2D Kawahara-Burgers equation posed on a channel-type strip was considered. The existence and uniqueness results for regular and weak solutions in weighted spaces as well as exponential decay of small solutions ... More
Evaluation of the mean cycle time in stochastic discrete event dynamic systemsDec 25 2012We consider stochastic discrete event dynamic systems that have time evolution represented with two-dimensional state vectors through a vector equation that is linear in terms of an idempotent semiring. The state transitions are governed by second-order ... More
A smooth component of the fractional Brownian motion and optimal portfolio selectionSep 21 2015Oct 13 2015We consider fractional Brownian motion with the Hurst parameters from (1/2,1). We found that the increment of a fractional Brownian motion can be represented as the sum of a two independent Gaussian processes one of which is smooth in the sense that it ... More
Optimal replication of random claims by ordinary integrals with applications in financeJan 03 2013Jan 04 2013By the classical Martingale Representation Theorem, replication of random vectors can be achieved via stochastic integrals or solutions of stochastic differential equations. We introduce a new approach to replication of random vectors via adapted differentiable ... More
On stationary solutions of two-dimensional Euler EquationJun 22 2012We study the geometry of streamlines and stability properties for steady state solutions of the Euler equations for ideal fluid.
On detecting the dependence of time seriesOct 13 2010This short note suggests a heuristic method for detecting the dependence of random time series that can be used in the case when this dependence is relatively weak and such that the traditional methods are not effective. The method requires to compare ... More
A constrained tropical optimization problem: complete solution and application exampleMay 07 2013Nov 03 2013The paper focuses on a multidimensional optimization problem, which is formulated in terms of tropical mathematics and consists in minimizing a nonlinear objective function subject to linear inequality constraints. To solve the problem, we follow an approach ... More
Explicit solution of a tropical optimization problem with application to project schedulingMar 21 2013Nov 10 2013A new multidimensional optimization problem is considered in the tropical mathematics setting. The problem is to minimize a nonlinear function defined on a finite-dimensional semimodule over an idempotent semifield and given by a conjugate transposition ... More
Rating alternatives from pairwise comparisons by solving tropical optimization problemsApr 03 2015Nov 28 2015We consider problems of rating alternatives based on their pairwise comparison under various assumptions, including constraints on the final scores of alternatives. The problems are formulated in the framework of tropical mathematics to approximate pairwise ... More
On $L_1$-distance between first exit times from two regionsMar 20 2003First exit times from regions and their dependence on variations of boundaries are discussed for diffusion processes. The paper presents an estimate of $L_1$-distance between exit times from two regions via expectations of exit times.
The integral estimations for ordinary differential equations and its application to the non-smooth optimal control problemsOct 29 2010The paper studies integral functionals with non-smooth functions from L_2 defined on solutions of ODEs. Some regularity is obtained in the form of estimates of L_2-norm for these functionals. This result is used for regularization of optimal control problems ... More
Dirac Eigenvalues of higher MultiplicityJan 16 2015Let M be a closed spin manifold of dimension at least three with a fixed topological spin structure. For any Riemannian metric, we can construct the associated Dirac operator. The spectrum of this Dirac operator depends on the metric of course. In 2005, ... More
Anomalous quark-gluon chromomagnetic interaction and high energy $ρ$-meson electroproductionNov 08 2011Feb 21 2012It is shown that existence of a large anomalous chromomagnetic moment of quark induced by non-perturbative structure of QCD leads to the additional contribution to exclusive $\rho$-meson electroproduction off proton target. The significant contribution ... More
A generalization of an inequality from IMO 2005Dec 08 2005A generalization of an inequality from IMO is proven.
Fractional Quantum Mechanics and Levy Path IntegralsOct 20 1999Oct 22 1999The fractional quantum and statistical mechanics have been developed via new path integrals approach.
On recovering solutions for SPDEs from their averagesNov 01 2016We study linear stochastic partial differential equations of parabolic type. We consider a new boundary value problem where a Cauchy condition is replaced by a prescribed average of the solution over time and probabilistic space. Well-posedness, existence, ... More
On sampling theorem with sparse decimated samplesMay 02 2016Jun 13 2016The classical sampling Nyquist-Shannon-Kotelnikov theorem states that a band-limited continuous time function is uniquely defined by infinite two-sided sampling series taken with a sufficient frequency. The paper shows that these band-limited functions ... More
Signatures of Right-Handed Majorana neutrinos and gauge bosons in $e γ$ CollisionsSep 27 2002Nov 28 2002The process $e^- \gamma \to e^+ W_R^- W_R^-$ is studied in the framework of the Left-Right symmetric model. It is shown that this reaction and $e^- \gamma \to l^+ W_R^- W_R^-$ for the arbitrary final lepton are likely to be discovered for CLIC collider ... More
Using tropical optimization to solve constrained minimax single-facility location problems with rectilinear distanceNov 24 2015Nov 28 2015We consider a constrained minimax single-facility location problem with addends on the plane with rectilinear distance. The problem is first formulated in a standard form, and then represented in terms of tropical mathematics as a constrained optimization ... More
Tests for Comparing Weighted Histograms. Review and ImprovementsJun 21 2016Sep 10 2016Histograms with weighted entries are used to estimate probability density functions. Computer simulation is the main application of this type of histograms. A review on chi-square tests for comparing weighted histograms is presented in this paper. Improvements ... More
On one sided band-limitness and extrapolation of sequencesAug 16 2012Aug 29 2016The paper suggests a notion of left band-limitness for one-sided semi-infinite sequences representing traces of two-sided band-limited sequences. A method of detecting these sequences is obtained. For more general one-sided sequences without this feature, ... More
Theoretical Aspects of Semileptonic B decaysJun 30 2003Strong interactions are addressed in connection to extracting |V_{cb}| and determining heavy quark parameters. A comprehensive approach allows a robust analysis not relying on a 1/m_c expansion; a percent defendable accuracy in |V_{cb}| becomes realistic. ... More
BLM-Resummation and OPE in Heavy Flavor TransitionsOct 20 1996Nov 04 1996An all-order resummation is performed for the effect of the running of the strong coupling in the zero recoil sum rule for the axial current and for the kinetic operator \vec\pi^2. The perturbative corrections to well-defined objects of OPE turn out to ... More
Heavy quark expansion in beauty: recent successes and problemsSep 10 2004The status of the QCD-based heavy quark expansion is briefly reviewed. A good agreement between properly applied theory and new precision data is observed. Critical remarks on certain recent claims from HQET are presented. Recent applications to the exclusive ... More
Combinatorial fiber bundles and fragmentation of a fiberwise PL-homeomorphismAug 30 2007Sep 16 2007With a compact PL manifold X we associate a category T(X). The objects of T(X) are all combinatorial manifolds of type X, and morphisms are combinatorial assemblies. We prove that the homotopy equivalence BT (X) \approx BPL(X) holds, where PL(X) is the ... More
Parabolic equations with the second order Cauchy conditions on the boundaryAug 15 2007The paper studies some ill-posed boundary value problems on semi-plane for parabolic equations with homogenuous Cauchy condition at initial time and with the second order Cauchy condition on the boundary of the semi-plane. A class of inputs that allows ... More
Backward parabolic Ito equations and second fundamental inequalityJun 23 2006Jul 26 2010Regularity of solutions is studied for backward stochastic parabolic Ito equations. An analog of the second energy inequality and the related existence theorem are obtained for domains with boundary.
Representation of functionals of Ito processes and their first exit timesJun 23 2006Jul 28 2010The representation theorem is obtained for functionals of non-Markov processes and their first exit times from bounded domains. These functionals are represented via solutions of backward parabolic Ito equations. As an example of applications, analogs ... More
On detecting and quantification of randomness for one-sided sequencesJan 24 2016Jun 22 2016The paper studies discrete time processes and their predictability and randomness in deterministic pathwise setting, without using probabilistic assumptions on the ensemble. We suggest some approaches to quantification of randomness based on frequency ... More
Using tropical optimization to solve constrained minimax single-facility location problems with rectilinear distanceNov 24 2015Sep 07 2017The aim of this paper is twofold: first, to extend the area of applications of tropical optimization by solving new constrained location problems, and second, to offer new closed-form solutions to general problems that are of interest to location analysis. ... More
Algebraic solution to a constrained rectilinear minimax location problem on the planeDec 25 2012We consider a constrained minimax single facility location problem on the plane with rectilinear distance. The feasible set of location points is restricted to rectangles with sides oriented at a 45 degrees angle to the axes of Cartesian coordinates. ... More
An algebraic approach to project schedule development under precedence constraintsOct 24 2012An approach to schedule development in project management is developed within the framework of idempotent algebra. The approach offers a way to represent precedence relationships among activities in projects as linear vector equations in terms of an idempotent ... More
Two unconditionally implied parameters and volatility smiles and skewsMar 20 2013Apr 22 2013The paper studies estimation of parameters of diffusion market models from historical data. The standard definition of implied volatility for these models presents its value as an implicit function of several parameters, including the risk-free interest ... More
Predictors for discrete time processes with energy decay on higher frequenciesDec 07 2011Aug 21 2018The predictability of discrete-time processes is studied in a deterministic setting. A family of one-step-ahead predictors is suggested for processes of which the energy decays at higher frequencies. For such processes, the prediction error can be made ... More
On the fractional stochastic integration for random non-smooth integrandsOct 05 2015Feb 18 2019The paper suggests a way of stochastic integration of random integrands with respect to fractional Brownian motion with the Hurst parameter H> 1/2. The integral is defined initially on the processes that are "piecewise" predictable on a short horizon. ... More
A pathwise inference method for the parameters of diffusion termsJun 18 2015Apr 11 2017We consider inference of the parameters of the diffusion term for Cox-Ingersoll-Ross and similar processes with a power type dependence of the diffusion coefficient from the underlying process. We suggest some original pathwise estimates for this coefficient ... More
On statistical indistinguishability of the complete and incomplete marketsSep 21 2012May 30 2013The possibility of statistical evaluation of the market completeness and incompleteness is investigated for continuous time diffusion stock market models. It is known that the market completeness is not a robust property: small random deviations of the ... More
On sampling theorem with sparse decimated samples: exploring branching spectrum degeneracyMay 02 2016Oct 30 2017The paper investigates possibility of recovery of sequences from their decimated subsequences. It is shown that this recoverability is associated with certain spectrum degeneracy of a new kind, and that a sequences of a general kind can be approximated ... More
Transmission of a continuous signal via one-bit capacity channelDec 12 2013Jan 21 2015We study the problem of the transmission of currently observed time variable signals via a channel that is capable of sending a single binary signal only for each measurement of the underlying process. For encoding and decoding, we suggest a modification ... More
Tropical optimization problems with application to project scheduling with minimum makespanMar 02 2014Jun 14 2016We consider multidimensional optimization problems in the framework of tropical mathematics. The problems are formulated to minimize a nonlinear objective function that is defined on vectors over an idempotent semifield and calculated by means of multiplicative ... More
Complete solution of a constrained tropical optimization problem with application to location analysisNov 12 2013Apr 16 2014We present a multidimensional optimization problem that is formulated and solved in the tropical mathematics setting. The problem consists of minimizing a nonlinear objective function defined on vectors over an idempotent semifield by means of a conjugate ... More
A Proof of Willcocks's ConjectureAug 19 2017Mar 03 2018We give a proof of Willcocks's Conjecture, stating that if $p - q$ and $p + q$ are relatively prime, then there exists a Hamiltonian tour of a $(p, q)$-leaper on a square chessboard of side $2(p + q)$. The conjecture was formulated by T. H. Willcocks ... More
Densities mixture unfolding for data obtained from detectors with finite resolution and limited acceptanceOct 06 2014Jan 05 2015A procedure based on a Mixture Density Model for correcting experimental data for distortions due to finite resolution and limited detector acceptance is presented. Addressing the case that the solution is known to be non-negative, in the approach presented ... More
CHIWEI: A code of goodness of fit tests for weighted and unweighted histogramsApr 19 2011Oct 10 2011A self-contained Fortran-77 program for goodness of fit tests for histograms with weighted entries as well as with unweighted entries is presented. The code calculates test statistics for case of histogram with normalized weights of events and in case ... More
The 2D Kawahara equation on half-stripFeb 11 2014We formulate on a half-strip an initial boundary value problem for the two-dmensional Kawahara equation. Existence and uniqueness of a regular solution as well as the exponential decay rate for the elevated norm of small solutions are proven.
Maximin setting for investment problems and fixed income management with observable but non-predictable parametersJul 27 2002We study optimal investment problem for a diffusion market consisting of a finite number of risky assets (for example, bonds, stocks and options). Risky assets evolution is described by Ito's equation, and the number of risky assets can be larger than ... More
Evaluation of the Lyapunov exponent for generalized linear second-order exponential systemsDec 25 2012We consider generalized linear stochastic dynamical systems with second-order state transition matrices. The entries of the matrix are assumed to be either independent and exponentially distributed or equal to zero. We give an overview of new results ... More
First Order BSPDEs in higher dimension for optimal control problemsMar 22 2016Oct 30 2018The paper studies the First Order BSPDEs (Backward Stochastic Partial Differential Equations) suggested earlier for a case of multidimensional state domain with a boundary. These equations represent analogs of Hamilton-Jacobi-Bellman equations and allow ... More
Optimal data recovery and forecasting with dummy long-horizon forecastsApr 29 2016The paper suggests a method of recovering of missing values based on optimal approximation by band-limited processes for sequences, i.e. discrete time processes, that are not necessarily band-limited. The problem is considered in the pathwise setting, ... More
A paradox of diffusion market model related with existence of winning combinations of optionsMar 19 2001We consider strategies of investments into options and diffusion market model. It is shown that there exists a correct proportion between "put" and "call" in the portfolio such that the average gain is almost always positive for a generic Black and Scholes ... More
Stochastic Theory of Foreign Exchange Market DynamicsSep 29 1999A new stochastic theory of a foreign exchange markets dynamics is developed. As a result we have the new probability distribution which well describes statistical and scaling dependencies ''experimentally'' observed in foreign exchange markets in recent ... More
Pathwise estimation of the diffusion term for Cox-Ingersoll-Ross and similar processesJun 18 2015Jun 19 2015We consider estimation of the diffusion term for Cox-Ingersoll-Ross and similar processes with a power type dependence of the diffusion coefficient from the underlying process. We suggest some new pathwise estimates for this coefficient and for the power ... More
On recovering parabolic diffusions from their time-averagesSep 07 2016Oct 11 2016The paper study a possibility to recover a parabolic diffusion from its time-average when the values at the initial time are unknown. This problem can be reformulated as a new boundary value problem where a Cauchy condition is replaced by a prescribed ... More
First Order BSPDEs: examples in higher dimensionMar 22 2016May 17 2016The paper studies the First Order BSPDEs (Backward Stochastic Partial Differential Equations)suggested earlier for a case of multidimensional state domain with a boundary. These equations represent analogs of Hamilton-Jacobi-Bellman equations and allow ... More
Predictors for time series with energy decay on higher frequenciesDec 07 2011Aug 07 2012The predictability of discrete-time processes is studied in a deterministic setting. A family of one-step-ahead predictors is suggested for processes of which the energy decays at higher frequencies. For such processes, the prediction error can be made ... More
Strong interaction effects in semileptonic B decaysOct 02 2002Strong interaction effects are addressed in connection to extracting |V_{cb}|. A comprehensive approach is described not relying on a 1/m_c expansion; it allows a percent accuracy without ad hoc assumptions about higher-order effects. An alternative to ... More
Topics in the Heavy Quark ExpansionOct 30 2000Nov 06 2000Achievements in the heavy quark theory over the last decade are reviewed, with the main emphasis put on dynamical methods which quantify nonperturbative effects via application of the Operator Product Expansion. These include the total weak decay rates ... More
Perturbative corrections to the semileptonic b-decay moments: E^\ell_{cut} dependence and running-α_s effects in the OPE approachMar 15 2004We have calculated the perturbative corrections to all the structure functions in the semileptonic decays of a heavy quark. Assuming an arbitrary gluon mass as a technical tool allowed to obtain in parallel all the BLM corrections. We report the basic ... More
On the chromomagnetic expectation value μ_G^2 and higher power corrections in heavy flavor mesonsNov 13 2001Nov 25 2001The important parameter \mu_G^2 of the heavy quark expansion is analyzed including perturbative and power corrections. It is found that \mu_G^2(2GeV) is known with a few percent accuracy. The perturbative corrections are computed and found small. A nonperturbative ... More
Universal estimate of the gradient for parabolic equationsSep 06 2007Apr 29 2008We suggest a modification of the estimate for weighted Sobolev norms of solutions of parabolic equations such that the matrix of the higher order coefficients is included into the weight for the gradient. More precisely, we found the upper limit estimate ... More
On recovering missing values for sequences in a pathwise settingApr 18 2016Sep 18 2018The paper suggests a frequency criterion of error-free recoverability of a missing value for sequences, i.e. discrete time processes, in a pathwise setting without probabilistic assumptions. The paper establishes error-free recoverability for classes ... More
A tropical extremal problem with nonlinear objective function and linear inequality constraintsDec 26 2012We consider a multidimensional extremal problem formulated in terms of tropical mathematics. The problem is to minimize a nonlinear objective function, which is defined on a finite-dimensional semimodule over an idempotent semifield, subject to linear ... More
Liouville theorem for Beltrami flowMar 06 2014We prove that the Beltrami flow of ideal fluid in $R^3$ of a finite energy is zero.
Precision calculations for Higgs-boson production at hadron collidersSep 21 2012The next-to-next-to-leading order (NNLO) calculation of the effective Higgs gluon coupling $C_1$ for the lightest Minimal Supersymmetric Standard Model (MSSM) Higgs boson $h^0$ is presented. Selected numerical results for the total production cross section ... More
Machine learning approach to inverse problem and unfolding procedureApr 12 2010May 25 2011A procedure for unfolding the true distribution from experimental data is presented. Machine learning methods are applied for simultaneous identification of an apparatus function and solving of an inverse problem. A priori information about the true distribution ... More
On martingale measures and pricing for continuous bond-stock market with stochastic bondAug 03 2011Sep 30 2014This papers addresses the stock option pricing problem in a continuous time market model where there are two stochastic tradable assets, and one of them is selected as a num\'eraire. It is shown that the presence of arbitrarily small stochastic deviations ... More
On the isomorphism problem for non-ergodic systems with discrete spectrumNov 15 2017Jan 05 2018The article presents a new perspective on the isomorphism problem for non-ergodic measure-preserving dynamical systems with discrete spectrum which is based on the connection between ergodic theory and topological dynamics constituted by topological models. ... More
Pseudogap and the chemical potential position topology in multiband superconductorsJun 25 2015Original definition of the pseudogap [11,12] allowes to connect it conceptually with a topological insulator. It concerns the multiband superconductivity background with variable chemical potential position.