1,125 research outputs found

    Vlasov scaling for stochastic dynamics of continuous systems

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    We describe a general scheme of derivation of the Vlasov-type equations for Markov evolutions of particle systems in continuum. This scheme is based on a proper scaling of corresponding Markov generators and has an algorithmic realization in terms of related hierarchical chains of correlation functions equations. Several examples of the realization of the proposed approach in particular models are presented.Comment: 23 page

    Non-equilibrium stochastic dynamics in continuum: The free case

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    We study the problem of identification of a proper state-space for the stochastic dynamics of free particles in continuum, with their possible birth and death. In this dynamics, the motion of each separate particle is described by a fixed Markov process MM on a Riemannian manifold XX. The main problem arising here is a possible collapse of the system, in the sense that, though the initial configuration of particles is locally finite, there could exist a compact set in XX such that, with probability one, infinitely many particles will arrive at this set at some time t>0t>0. We assume that XX has infinite volume and, for each α1\alpha\ge1, we consider the set Θα\Theta_\alpha of all infinite configurations in XX for which the number of particles in a compact set is bounded by a constant times the α\alpha-th power of the volume of the set. We find quite general conditions on the process MM which guarantee that the corresponding infinite particle process can start at each configuration from Θα\Theta_\alpha, will never leave Θα\Theta_\alpha, and has cadlag (or, even, continuous) sample paths in the vague topology. We consider the following examples of applications of our results: Brownian motion on the configuration space, free Glauber dynamics on the configuration space (or a birth-and-death process in XX), and free Kawasaki dynamics on the configuration space. We also show that if X=RdX=\mathbb R^d, then for a wide class of starting distributions, the (non-equilibrium) free Glauber dynamics is a scaling limit of (non-equilibrium) free Kawasaki dynamics

    A note on an integration by parts formula for the generators of uniform translations on configuration space

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    An integration by parts formula is derived for the first order differential operator corresponding to the action of translations on the space of locally finite simple configurations of infinitely many points on Rd. As reference measures, tempered grand canonical Gibbs measures are considered corresponding to a non-constant non-smooth intensity (one-body potential) and translation invariant potentials fulfilling the usual conditions. It is proven that such Gibbs measures fulfill the intuitive integration by parts formula if and only if the action of the translation is not broken for this particular measure. The latter is automatically fulfilled in the high temperature and low intensity regime

    Gibbs states of continuum particle systems with unbounded spins : existence and uniqueness

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    We study an infinite system of particles chaotically distributed over a Euclidean space Rd. Particles are characterized by their positions x∈Rd and an internal parameter (spin) σx∈Rm and interact via position-position and (position dependent) spin-spin pair potentials. Equilibrium states of such system are described by Gibbs measures on a marked configuration space. Due to the presence of unbounded spins, the model does not fit the classical (super-) stability theory of Ruelle. The main result of the paper is the derivation of sufficient conditions of the existence and uniqueness of the corresponding Gibbs measures

    Using dashboards for the business processes status analysis

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    This paper describes business process status analysis using the dashboards. The dashboards are considered as those, which belong to the most preferred Business Intelligence tools nowadays, which are used by both higher managers and ordinary employees. Existing software tools for dashboard design were reviewed, as well as the most popular visualization charts were outlined. The place and role of analytical dashboards as part of business process management is described

    Temporal solitons in optical microresonators

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    Dissipative solitons can emerge in a wide variety of dissipative nonlinear systems throughout the fields of optics, medicine or biology. Dissipative solitons can also exist in Kerr-nonlinear optical resonators and rely on the double balance between parametric gain and resonator loss on the one hand and nonlinearity and diffraction or dispersion on the other hand. Mathematically these solitons are solution to the Lugiato-Lefever equation and exist on top of a continuous wave (cw) background. Here we report the observation of temporal dissipative solitons in a high-Q optical microresonator. The solitons are spontaneously generated when the pump laser is tuned through the effective zero detuning point of a high-Q resonance, leading to an effective red-detuned pumping. Red-detuned pumping marks a fundamentally new operating regime in nonlinear microresonators. While usually unstablethis regime acquires unique stability in the presence of solitons without any active feedback on the system. The number of solitons in the resonator can be controlled via the pump laser detuning and transitions to and between soliton states are associated with discontinuous steps in the resonator transmission. Beyond enabling to study soliton physics such as soliton crystals our observations open the route towards compact, high repetition-rate femto-second sources, where the operating wavelength is not bound to the availability of broadband laser gain media. The single soliton states correspond in the frequency domain to low-noise optical frequency combs with smooth spectral envelopes, critical to applications in broadband spectroscopy, telecommunications, astronomy and low phase-noise microwave generation.Comment: Includes Supplementary Informatio

    Intersection local times of independent fractional Brownian motions as generalized white noise functionals

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    In this work we present expansions of intersection local times of fractional Brownian motions in Rd\R^d, for any dimension d1d\geq 1, with arbitrary Hurst coefficients in (0,1)d(0,1)^d. The expansions are in terms of Wick powers of white noises (corresponding to multiple Wiener integrals), being well-defined in the sense of generalized white noise functionals. As an application of our approach, a sufficient condition on dd for the existence of intersection local times in L2L^2 is derived, extending the results of D. Nualart and S. Ortiz-Latorre in "Intersection Local Time for Two Independent Fractional Brownian Motions" (J. Theoret. Probab.,20(4)(2007), 759-767) to different and more general Hurst coefficients.Comment: 28 page
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