A simple almost-periodicity criterion and applications (Q1086413)

A simple sufficient condition for almost periodicity of functions \(u: {\mathbb{R}}\to X\) into a complete metric space X is observed and exploited for solutions of periodic linear ordinary differential equations in a Euclidean space (e.g. Hill's equation) and trajectories of periodic processes on a complete metric space (e.g. semilinear partial differential equations).