496 research outputs found
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
Anomalous diffusion. A competition between the very large jumps in physical and operational times
In this paper we analyze a coupling between the very large jumps in physical
and operational times as applied to anomalous diffusion. The approach is based
on subordination of a skewed Levy-stable process by its inverse to get two
types of operational time - the spent and the residual waiting time,
respectively. The studied processes have different properties which display
both subdiffusive and superdiffusive features of anomalous diffusion underlying
the two-power-law relaxation patterns.Comment: 6 pages, 3 figures; corrected versio
Hamiltonian formalism of fractional systems
In this paper we consider a generalized classical mechanics with fractional
derivatives. The generalization is based on the time-clock randomization of
momenta and coordinates taken from the conventional phase space. The fractional
equations of motion are derived using the Hamiltonian formalism. The approach
is illustrated with a simple-fractional oscillator in a free state and under an
external force. Besides the behavior of the coupled fractional oscillators is
analyzed. The natural extension of this approach to continuous systems is
stated. The interpretation of the mechanics is discussed.Comment: 16 pages, 5 figure
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
- …
