ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)


Synchronization of coupled generators of quasi-periodic oscillations upon destruction of invariant curve

The purpose of this study is to describe the complete picture of synchronization of two coupled generators of quasi-periodic oscillations, to classify various types of synchronization, to study features of occurrence and destruction of multi-frequency quasi-periodic oscillations. Methods. The object of the research is systems of ordinary differential equations of various dimensions. The work uses the fourth-order Runge–Kutta method to solve a system of differential equations.

Numerical study of dynamical system generated by CABC vector field

Purpose of this study is to construct a helical vector field and analyze the dynamical system generated by it. Classic example of such field is the ABC (Arnold–Beltrami–Childress) flow, which is equations stationary solution of the dynamics of ideal incompressible fluid. The article numerically studies the structure of the phase space of a dynamical system determined by the constructed vector field under various assumptions. Methods. When constructing a dynamic system, the approach proposed for helical fields from the class of CABC (Compressible ABC) flows was used.

Multistability and memory effects in dynamical system with cosymmetric potential

The purpose of present study is the analysis of strong multistability in a dynamical system with cosymmetry. We study the dynamics and realization of steady-states in a mechanical system with two degrees of freedom. The minimum potential energy of the system is achieved on a curve in the form of an ellipse, which gives rise to a continuum family of equilibria and strong multistability. This problem belongs to the class of dynamical systems with cosymmetry. Methods.

Self-oscillating system generating rough hyperbolic chaos

Topic and aim. The aim of the work is design of rough chaos generator, whose attractor implements dynamics close to Anosov flow on a manifold of negative curvature, as well as constructing and analyzing mathematical model, and
conducting circuit simulation of the dynamics using the Multisim software.

Investigated models. A mathematical model is considered that is a set of ordinary differential equations of the ninth order with algebraic nonlinearity, and a circuit representing the chaos generator is designed.

Chaotic dynamics of pendulum ring chain with vibrating suspension

Topic and aim. The aim of the work is to introduce into consideration a mechanical system that is a chain of oscillators capable of demonstrating hyperbolic chaos due to the presence of attractor in the form of the Smale–Williams solenoid. Investigated model. We study the pendulum ring chain with parametric excitation due to the vertical oscillating motion of the suspension alternately at two different frequencies, so that the standing wave patterns appear in the chain with a spatial scale that differs by three times.

Dynamics of two field­coupled spin­transfer oscillators

The model of two field­coupled spin­transfer oscillators has been derived and studied. It has been shown that this model demonstrates phase synchronization in a wide bandwidth, quasiperiodic oscillations and chaos.

Regular and chaotic oscillations in astrocyte model with regulation of calcium release kinetics

The dynamics of an astrocyte model is investigated. The astrocytes represent a type of glial cells regulating oscillations of major signaling cells, e.g. neurons. Subserved by complex molecular mechanisms the astrocytes generate calcium auto-oscillations which, in turn, are associated with the release of neuroactive chemicals into extracellular space. At variance with classical astrocyte models the three-component model considered takes into account a regulation of calcium release due to nonlinear dynamics of inositol-1,4,5 trisphosphate (IP3).

Largest Lyapunov exponent of chaotic oscillatory regimes computing from point processes in the noise presence

We propose a modified method for computing of the largest Lyapunov exponent of chaotic oscillatory regimes from point processes at the presence of measurement noise that does not influence on the system’s dynamics. This modification allow a verification to be made of the estimated dynamical characteristics precision. Using the Rossler system in the regime of a phase-coherent chaos we consider features of application of this method to point processes of the integrate-and-fire and the threshold-crossing models. Download full version

Fractal geometry

The article deals with the bases of fractal geometry and fates of its creators. The biographies and the discoveries of Felix Hausdorff and Abram Besicovitch – the main characters of the great play called fractal geometry – are presented with the possible degree of detail. There is no doubt that the author and director of this play was Benoit Mandelbrot. The article presents his biography and brief descriptions of the lives of his predecessors: Henri Poincare, Maurice Gaston Julia and Pierre Gaston Jose Fatou.

Uniformly hyperbolic attractor in a system based on coupled oscillators with «figure-eight» separatrix

A new autonomous system with chaotic dynamics corresponding to Smale–Williams attractor in Poincare map is introduced. The system is constructed on the basis of the model with «figure-eight» separatrix on the phase plane discussed in former times by Y.I. Neimark. Our system is composed of two Neimark subsystems with generalized coordinates x and y. It is described by the equations with additional terms due to which the system becomes self-oscillating.