A Lusternik-Schnirelmann Type Theorem for C¹-Frechet Manifolds

This is the authors' abstract. We don't add key points for this paper.

We prove a Lusternik-Schnirelmann type theorem for a C1- function φ : M → R, where M is a connected infinite dimensional Frechet manifold of class C1. To this end, in this context we prove the so-called Deformation Lemma and by using it we derive the result generalizing the Minimax Principle.