Frum-Ketkov Type Multivalued Operators

Abstract

Let (M, d) be a metric space, X subset of M be a nonempty closed subset and K subset of M be a nonempty compact subset. By definition, an upper semi-continuous multivalued operator F : X -> P (X) is said to be a strong Frum-Ketkov type operator if there exists alpha is an element of]0, 1[ such that e(d)(F(x), K) <= alpha D-d (x, K), for every x is an element of X, where e(d) is the excess functional generated by d and D-d is the distance from a point to a set. In this paper, we will study the fixed points of strong Frum-Ketkov type multivalued operators.