Large scale oscillatory behaviour in loaded asymmetric systems (Q1096068)

The authors study \(2\pi\)-periodic solutions of ``asymmetric'' nonlinear differential equations of the form \(u''+g(u)=s(1+\epsilon h(t)),\) where s is a constant, \(\epsilon\) a small parameter, \(h(t+2\pi)=h(t)\) and \(g'(+\infty)\neq g'(-\infty)\). Depending on g(u) there exist many such solutions close to s. \{Reviewer's remark: These results are closely related to \textit{H. Ehrmann} [Z. Angew. Math. Mech. 35, 326-327 (1955; Zbl 0065.074)].\}