Periodic solutions of forced Liénard equations (Q1200106)

The paper proves sufficient conditions for the existence of \(T\)-periodic solutions \(x(t)\) of the differential equation \(\ddot x+f(x)\dot x+g(t,x)=e(t)\) where \(g(t+T,x)=g(t,x)\) and \(e(t+T)=e(t)\). The theory of nonhomogeneous linear periodic systems and the Schauder fixed point theorem are used.