Almost Periodic Solutions of Periodic Linear Partial Functional Differential Equations

Abstract

We study conditions for the abstract periodic linear functional differential equation = Ax + F(t)x_t + f(t) to have almost periodic with the same structure of frequencies as f. The main conditions are stated in terms of the spectrum of the monodromy operator associated with the equation and the frequencies of the forcing term f. The obtained results extend recent results on the subject. A discussion on how the results could be extended to the case when A depends on t is given.