A qualitative study of a trigonometric autonomous system
A qualitative analysis is made of the autonomous system \(\dot x = \sin y\), \(\dot y = - \sin x + d \sin ny\) defined on the torus \(T^ 2 = [-\pi, \pi] \times [-\pi, \pi]\), where \(d \in R\) and \(n\) is a positive integer. It is proved that for \(0 < d \ll I\) the system has at least \(2(n-1)\) limit cycles.
scientific article; zbMATH DE number 566445