A New Proof and an Extension of a Theorem of P. Rabinowitz Concerning Nonlinear Wave Equations

摘要

In 1978, P. Rabinowitz proved a theorem concerned with the existence of a nontrivial periodic solution of a nonlinear wave equation with a continuous increasing superlinear nonlinear term. In this paper we present a new and simpler proof of this theorem and relax an assumption on the nonlinear term, which is a discontinuous nondecreasing function. (Author)