Fixpunktsätze für limeskompakte mengenwertige Abbildungen in nicht notwendig lokalkonvexen topologischen Vektorräumen
We describe the extension of the multiplication on a not-necessarily-discrete topological monoid to its flow compactification. We offer two applications. The first is a nondiscrete version of Hindman’s Theorem, and the second is a characterization of the projective minimal and elementary flows in terms of idempotents of the flow compactification of the monoid.
In this paper fixed point theorems for maps with nonempty convex values and having the local intersection property are given. As applications several minimax inequalities are obtained.
In this paper generalized quasivariational inequalities on Fréchet spaces are deduced from new fixed point theory of Agarwal and O’Regan [1] and O’Regan [7].
For a topological space let be the set of all compact subsets of . The purpose of this paper is to characterize Lindelöf Čech-complete spaces by means of the sets . Similar characterizations also hold for Lindelöf locally compact , as well as for countably -determined spaces . Our results extend a classical result of J. Christensen.
Several classes of hereditarily normal spaces are characterized in terms of extending upper semi-continuous compact-valued mappings. The case of controlled extensions is considered as well. Applications are obtained for real-valued semi-continuous functions.
We prove that a compact family of bounded condensing multifunctions has bounded condensing set-theoretic union. Compactness is understood in the sense of the Chebyshev uniform semimetric induced by the Hausdorff distance and condensity is taken w.r.t. the Hausdorff measure of noncompactness. As a tool, we present an estimate for the measure of an infinite union. Then we apply our result to infinite iterated function systems.