arXiv subjects
Publications and source records attributed to Yuriy E. Kuzovlev.
A very good as well as simple approximate solution is suggested to the problem which flat circular distribution of electric current in finite film produces a given axially symmetric distribution of normal-to-film magnetic field.
It is shown that evolution of an open quantum system can be exactly described in terms of wave function which obeys Schrodinger equation with randomly varying parameters whose statistics is universally determined by separate dynamics of the system's environment. Corresponding stochastic evolution of the wave function is unitary on average, and this property implies optical theorem for inelastic scattering as demonstrated by the example of one-dimensional conducting channel with thermally fluctuating potential perturbation.
The generating functional is derived for the fluctuation-dissipation relations which result from the unitarity and reversibility of microscopic dynamics and connect various statistical characteristics of many consecutive (continuous) observations in a quantum system subjected to external perturbations. Consequences of these relations in respect to the earlier suggested stochastic representation of interaction between two systems are considered.
The discrete unitary (reversible) analogues of the continuous (irreversible) tent maps are numerically investigated, in particular, the lengths probability distribution of their periodic orbits. It is found that its density can be well approximated by the inverse proportional law.
Exact generalized stochastic representation of deterministic interaction between two dynamical (quantum or classical) systems is derived which helps when considering one of them to replace another by equivalent commutative ($c$-number valued) random sources. The method is applied to classical Brownian motion of a particle in a gas, and statistics of this motion is reduced to statistics of the gas response to perturbations.
Generalized Langevin equation for characteristic functional of many-electron system dynamically interacting with a thermostat and besides subjected to external perturbation and observation is derived and formulated in terms of one-particle but stochastic density matrix. The scheme naturally includes also direct electron-electron interactions. Corresponding approximate Fokker-Plank kinetic equation is discussed. We point out that it possesses continuous degeneracy of stationary solution and therefore can hide long-correlated fluctuations of electron transport even if thermostat noise is short-correlated.
The 1/f-noise is considered which has no relation to long-lasting processes but originates from the same dynamical mechanisms as what are responsible for the loss of memory, fast relaxation and usual shot noise. The universal long-range statistics of memoryless random flows of events and of related Brownian motion is analysed whose peculiarity is close connection between spectral properties and non-Gaussian probabilistic properties both determined by only short-range characteristic time scales. The exact relations between equilibrium and non-equilibrium 1/f-noise in thermodynamical systems are presented. The existence of long-living higher-order correlations and flicker noise in the Kac's ring model is demonstrated. It is shown that conventional Boltzmannian gas kinetics losses 1/f-noise because incorrectly takes into account the conservation of particles and probabilities in collision events. The correctly performed translation of BBGKY hierarchy into kinetical language, under Boltzmann-Grad limit, results in infinite chain of kinetical equations which describe probability distributions on the hypersurfaces corresponding to encounters and collisions of particles. These equations can be reduced to Boltzmann's equation only in the limit of spatially uniform gas, but generally forbid the molecular chaos. If being applied to Brownian motion of gas particles, the theory yields 1/f fluctuations of self-diffusivity and mobility. This is example of Hamiltonian dynamics which produces 1/f-noise without any slow processes and long life-times.