Almost Periodicity in Linear Topological Spaces Revisited

Abstract

Almost periodic functions with values in Banach spaces, and even more generally in Fréchet spaces and $p$-Fréchet spaces, have been investigated by many authors. The purpose of this paper is to investigate the extent to which some results of these authors also hold in the setting of topological vector spaces, not necessarily locally convex or $p$-locally convex. In fact, most of our results (Theorems 3.3, 3.5-3.8) do not require even completeness or metrizability of the range space. We thus extend and unify several known results.