Faculty of Mathematics and Computer Science, Babeş-Bolyai University, Cluj-Napoca 400084, Romania
Copyright © 2006 S. Cobzaş. This is an open access article distributed under the
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Abstract
In the appendix to the book by F. F. Bonsal, Lectures on
Some Fixed Point Theorems of Functional Analysis (Tata Institute,
Bombay, 1962) a proof by Singbal of the Schauder-Tychonoff fixed
point theorem, based on a locally convex variant of Schauder
mapping method, is included. The aim of this note is to show that
this method can be adapted to yield a proof of Kakutani fixed
point theorem in the locally convex case. For the sake of
completeness we include also the proof of Schauder-Tychonoff
theorem based on this method. As applications, one proves a
theorem of von Neumann and a minimax result in game theory.