Ulam stabilities of ordinary differential equations in a Banach space

Let (B;j j ) be a Banach space, A : B ! B be the infinitesimal generator of a C0- semigroup, I := (a;b) or (a;+1( and f 2 C(I B;B). In this paper we present and discuss four types of Ulam stability: Ulam-Hyers stability, generalized Ulam-Hyers stability, Ulam-Hyers-Rassias stability and generalized Ulam-Hyers-Rassias stability for the following differential equation u 0 (t) = A(u(t)) +f(t;u(t)); t2 I: