arXiv subjects

Dmitry Treschev

Publications and source records attributed to Dmitry Treschev.

21 records · Page 2Linked to original sources

arXiv2010

Hill's formula

In his study of periodic orbits of the 3 body problem, Hill obtained a formula relating the characteristic polynomial of the monodromy matrix of a periodic orbit and an infinite determinant of the Hessian of the action functional. A mathematically correct definition of the Hill determinant and a proof of Hill's formula were obtained later by Poincaré. We give two multidimensional generalizations of Hill's formula: to discrete Lagrangian systems (symplectic twist maps) and continuous Lagrangian systems. We discuss additional aspects which appear in the presence of symmetries or reversibility. We also study the change of the Morse index of a periodic trajectory after the reduction of order in a system with symmetries. Applications are given to the problem of stability of periodic orbits.

math.DS↗

arXiv2009

Oscillator and thermostat

We study the problem of a potential interaction of a finite-dimensional Lagrangian system (an oscillator) with a linear infinite-dimensional one (a thermostat). In spite of the energy preservation and the Lagrangian (Hamiltonian) nature of the total system, under some natural assumptions the final dynamics of the finite-dimensional component turns out to be simple while the thermostat produces an effective dissipation.

math.DS↗

arXiv2003

Continuous averaging in dynamical systems

The method of continuous averaging can be regarded as a combination of the Lie method, where a change of coordinates is constructed as a shift along solutions of a differential equation and the Neishtadt method, well-known in perturbation theory for ODE in the presence of exponentially small effects. This method turns out to be very effective in the analysis of one- and multi-frequency averaging, exponentially small separatrix splitting and in the problem of an inclusion of an analytic diffeomorphism into an analytic flow. We discuss general features of the method as well as the applications.

math.DS↗