On the Krein-Milman-Ky Fan theorem for convex compact metrizable sets.
Abstract
We extend the extension by Ky Fan of the Krein-Milman theorem. The $\Phi$-extreme points of a $\Phi$-convex compact metrizable space are replaced by the $\Phi$-exposed points in the statement of Ky Fan theorem. Our main results are based on new variational principles which are of independent interest. Several applications will be given.