Solar type III bursts with high-frequency cut-off

New results in the study of solar type III bursts observed with the UTR-2 radio telescope are presented. The main feature of these bursts is a high-frequency cut-off. The solar activity manifestation was connected with the emergency of a new group of solar spots behind the solar limb relative to an observer on the Earth. This burst type was identified by analyzing its frequency drift rate, duration and flux depending on frequency. The solar bursts were linked to a group of similar events. The cut-off frequency is different from burst to burst and lies within 30-55 MHz. The cut-off origin is considered in the context of propagation effects between the burst sources moving behind the solar limb and the ground-based radio instruments.Comment: 6 pages, 4 figures, 1 tabl

Memory Effects and Macroscopic Manifestation of Randomness

It is shown that due to memory effects the complex behaviour of components in a stochastic system can be transmitted to macroscopic evolution of the system as a whole. Within the Markov approximation widely using in ordinary statistical mechanics, memory effects are neglected. As a result, a time-scale separation between the macroscopic and the microscopic level of description exists, the macroscopic differential picture is no a consequence of microscopic non-differentiable dynamics. On the other hand, the presence of complete memory in a system means that all its components have the same behaviour. If the memory function has no characteristic time scales, the correct description of the macroscopic evolution of such systems have to be in terms of the fractional calculus.Comment: LaTeX, 18 pages, 1 postscript figure. New extended version, new paragraphs and references adde

Beam propagation in a Randomly Inhomogeneous Medium

An integro-differential equation describing the angular distribution of beams is analyzed for a medium with random inhomogeneities. Beams are trapped because inhomogeneities give rise to wave localization at random locations and random times. The expressions obtained for the mean square deviation from the initial direction of beam propagation generalize the "3/2 law".Comment: 4 page

Subordination model of anomalous diffusion leading to the two-power-law relaxation responses

We derive a general pattern of the nonexponential, two-power-law relaxation from the compound subordination theory of random processes applied to anomalous diffusion. The subordination approach is based on a coupling between the very large jumps in physical and operational times. It allows one to govern a scaling for small and large times independently. Here we obtain explicitly the relaxation function, the kinetic equation and the susceptibility expression applicable to the range of experimentally observed power-law exponents which cannot be interpreted by means of the commonly known Havriliak-Negami fitting function. We present a novel two-power relaxation law for this range in a convenient frequency-domain form and show its relationship to the Havriliak-Negami one.Comment: 5 pages; 3 figures; corrected versio

Fractional Integro-Differential Equations for Electromagnetic Waves in Dielectric Media

We prove that the electromagnetic fields in dielectric media whose susceptibility follows a fractional power-law dependence in a wide frequency range can be described by differential equations with time derivatives of noninteger order. We obtain fractional integro-differential equations for electromagnetic waves in a dielectric. The electromagnetic fields in dielectrics demonstrate a fractional power-law relaxation. The fractional integro-differential equations for electromagnetic waves are common to a wide class of dielectric media regardless of the type of physical structure, the chemical composition, or the nature of the polarizing species (dipoles, electrons, or ions)

Chaotic and pseudochaotic attractors of perturbed fractional oscillator

We consider a nonlinear oscillator with fractional derivative of the order alpha. Perturbed by a periodic force, the system exhibits chaotic motion called fractional chaotic attractor (FCA). The FCA is compared to the ``regular'' chaotic attractor. The properties of the FCA are discussed and the ``pseudochaotic'' case is demonstrated.Comment: 20 pages, 7 figure