Conditions of existence of bounded solutions of differential equation in Banach space on the real axis

Abstract

We consider an equation of the form $y''(t)- By(t) = f(t), \ t \in (-\infty, \infty)$, where $B$ is a positive operator in a Banach space. For the vector-valued function $f(t)$, we establish sufficient conditions under which a bounded solution to this equation exists and is unique.