Implicit multifunction theorems in complete metric spaces

Implicit multifunction theorems in complete metric spaces

In this paper, we establish some new characterizations of the metric regularity of implicit multifunctions in complete metric spaces by using the lower semicontinuous envelopes of the distance functions for set-valued mappings. Through these new characterizations it is possible to investigate implicit multifunction theorems based on coderivatives and on contingent derivatives as well as the per...

Variational Methods in Metric Regularity and Implicit Multifunction Theorems

Implicit Multifunction Theorems

We prove a general implicit function theorem for multifunctions with a metric estimate on the implicit multifunction and a characterization of its coderivative. Traditional open covering theorems, stability results, and sufficient conditions for a multifunction to be metrically regular or pseudo-Lipschitzian can be deduced from this implicit function theorem. We prove this implicit multifunctio...

Fixed Point Theorems in Complete Metric Spaces

THE STUDY in fixed point theory has generally developed in three main directions: generalization of conditions which ensure existence, and, if possible, uniqueness, of fixed points; investigation of the character of the sequence of iterates (T”x)~~~, where T: X + X, X a complete metric space, is the map under consideration; study of the topoligical properties of the set of fixed points, wheneve...

Common Fixed Point Theorems for Four Mappings in Complete Metric Spaces