Birkhoff-Kellogg theorems on invariant directions for multimaps
Several Birkhoff-Kellogg type theorems on invariant directions for \(\mathcal{U}^{\mathcal{K}}_{\mathcal{C}}\) multifunctions in Hausdorff locally convex topolocical vector spaces and in Hausdorff topological vector spaces are proved. As consequence, Birkhoff-Kellogg type results for Kakutani multifunctions, acyclic multifunctions, O'Neill multifunctions, approximable multifunctions, and multifunctions admissible in Górniewicz' sense are deduced. Also, invariant direction results for countably condensing multifunctions are presented.
scientific article; zbMATH DE number 1929991