Limit cycles for a class of third-order differential equations (Q976558)

The authors study the limit cycles of the following class of third-order ordinary differential equations \[ \dddot{x}-\mu\ddot{x}+\dot{x}-\mu x=\varepsilon F(x,\dot{x},\ddot{x},t) \] where \(\mu \neq 0\), and the dot means derivative with respect to variable \(t\), \(\varepsilon\) is small enough and \(F\in \mathcal{C}^2\) is a \(2\pi\)-periodic function of variable \(t\). The variables \(x\) and \(t\), and parameters \(\mu\) and \(\varepsilon\) are real.