Z. I. Sharifzoda, È. M. Muhamadiev, I. D. Nurov, “Cyclic solutions of the Pontryagin equation with a small parameter”, Itogi Nauki i Tekhniki. Sovrem. Mat. Pril. Temat. Obz., 2021, Volume 194,Pages <nobr>167

Cyclic solutions of the Pontryagin equation with a small parameter

Z. I. Sharifzoda^a, È. M. Muhamadiev^b, I. D. Nurov^a

^a Tajik National University, Dushanbe
^b Vologda State University

Abstract: In this paper, we examine the existence of periodic solutions to systems of nonlinear equations with a small parameter. We find conditions for the existence of periodic solutions, which expand the range of applicability of Pontryagin's method of small parameter.

Keywords: differential equation, periodic solution, topological methods, rotation of a vector field.

UDC: 517.91

MSC: 34A34

DOI: 10.36535/0233-6723-2021-194-167-171