Quantitative deformation theorems and critical point theory
Jean-Noël Corvellec · Pacific Journal of Mathematics · 1999
In the framework of critical point theory for continuous functionals defined on metric spaces, we show how quantitative deformation properties can be used to obtain saddle-point type results, even in the case when the usual geometric assumptions are not satisfied.We thus unify and extend to a nonsmooth setting some recent results of Schechter.