953 research outputs found
Mean Field Asymptotic Behavior of Quantum Particles with Initial Correlations
In the paper we consider the problem of the rigorous description of the
kinetic evolution in the presence of initial correlations of quantum large
particle systems. One of the developed approaches consists in the description
of the evolution of quantum many-particle systems within the framework of
marginal observables in mean field scaling limit. Another method based on the
possibility to describe the evolution of states within the framework of a
one-particle marginal density operator governed by the generalized quantum
kinetic equation in case of initial states specified by a one-particle marginal
density operator and correlation operators.Comment: 17 page
On the Initial-Value Problem to the Quantum Dual BBGKY Hierarchy
We develop a rigorous formalism for the description of the evolution of
observables in quantum systems of particles. We construct a solution of the
initial-value problem to the quantum dual BBGKY hierarchy of equations as an
expansion over particle clusters whose evolution are governed by the
corresponding-order dual cumulant (dual semi-invariant) of the evolution
operators of finitely many particles. For initial data from the space of
sequences of bounded operators the existence and uniqueness theorem is proved.Comment: 22 page
On Semigroups of Large Particle Systems and their Scaling Asymptotic Behavior
We consider semigroups of operators for hierarchies of evolution equations of
large particle systems, namely, of the dual BBGKY hierarchy for marginal
observables and the BBGKY hierarchy for marginal distribution functions. We
establish that the generating operators of the expansions for one-parametric
families of operators of these hierarchies are the corresponding order
cumulants (semi-invariants) of semigroups for the Liouville equations. We also
apply constructed semigroups to the description of the kinetic evolution of
interacting stochastic Markovian processes, modeling the microscopic evolution
of soft active matter. For this purpose we consider the mean field asymptotic
behavior of the semigroup generated by the dual BBGKY hierarchy for marginal
observables. The constructed scaling limit is governed by the set of recurrence
evolution equations, namely, by the Vlasov-type dual hierarchy. Moreover, the
relationships of this hierarchy of evolution equations with the Vlasov-type
kinetic equation with initial correlations are established.Comment: 17 pages. arXiv admin note: text overlap with arXiv:1308.450
Quantum Kinetic Evolution of Marginal Observables
We develop a rigorous formalism for the description of the evolution of
observables of quantum systems of particles in the mean-field scaling limit.
The corresponding asymptotics of a solution of the initial-value problem of the
dual quantum BBGKY hierarchy is constructed. Moreover, links of the evolution
of marginal observables and the evolution of quantum states described in terms
of a one-particle marginal density operator are established. Such approach
gives the alternative description of the kinetic evolution of quantum
many-particle systems to generally accepted approach on basis of kinetic
equations.Comment: 18 page
Quantitative estimation of business activity in the market of tourist services
The critical analysis of approaches of various authors to definition of the basic quantity indicators of the market of tourist services is carried out. Methods of calculation of such important characteristics of the tourist markets are offered, such as: capacity of the real and potential markets, the size of the market, market structure, factor of a saturation of the market. Information sources for an exact
establishment of size of the specified are considered
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