Ekeland's Variational Principle on Quasiordered Monoids

This paper deals with Ekeland's variational principle and some of its equivalents on quasioredered monoids. Indeed, Ekeland's variational principle, Kirk-Caristi fixed point theorem, Takahashi'sexistence principle and flower petal theorem on quasioredered monoids are given and also their equivalence are considered. Finally, an equilibrium formulation of Ekeland's principle is given

Keywords:

Qusiordered monoid , Order premetric , , Ekeland’s variational principle , flower petal