Proceedings of the Royal Society of Edinburgh: Section A Mathematics

Research Article

Periodic solutions of a nonlinear wave equation

Abbas Bahria1 and Haïm Brezisa1

a1 Analyse Numeŕique, Université Paris VI, Tour 55, 4 pl. Jussieu, 75230 Paris Cedex 05

Synopsis

We provide a sufficient and “almost” necessary condition for the existence of a periodic solution of the equation

S0308210500011896_eqnU1

where F is nondecreasing in u and has a small linear growth as |u|→∞.

(Received May 23 1979)