The intrinsic mountain pass principle
The authors extend the results of \textit{M. Schechter} [Pac. J. Math. 171, No. 2, 529-544 (1995; Zbl 0901.58008)] dropping any smoothness or even continuity assumptions on the considered functional. For this, a new version of the deformation lemma is proved.
scientific article; zbMATH DE number 1346179