Marcin Borkowski
Spaces with abstract polyhedra and fixed points
In 1988, Horvath defined a certain structure in topological spaces, generalizing (among others) a convex polyhedron in Euclidean space, a convex subset of a vector space and a hyperconvex set. In 1995, S. Park and H. Kim proved some fixed point theorems for u.s.c. multifunctions defined on a space with such a structure. We will discuss the proofs and consequences of their theorems.