ON SOME PERTURBED VARIATIONAL PRINCIPLES: CONNEXIONS AND APPLICATIONS

We prove a modified version of a theorem of Ghoussoub and Maurrey, which is a general smooth perturbation variational principle, by operating some changes on it. Two other theorems, which are also variational principles, are discussed, one of them being a generalization of a theorem due to Deville, Godefroy and Zizler, while the other is a linear perturbation variational principle in reflexive spaces. Several connexions with other forms of variational principles are pointed out and two applications of these results are given.