Integrated semigroups,C-semigroups and the abstract Cauchy problem

LetA be a linear operator on a Banach space. We consider when the following holds. (*)u′(t,x)=A(u(t,x)) (t≥0),u(0,x)=x, has a unique solution, for allx in the domain ofA ⁿ⁺¹ . We discuss the relationship between (*), integrated semigroups, and C-semigroups. We use this to obtain new results about integrated semigroups and the abstract Cauchy problem. We give several examples where (*) may be easily shown using C-semigroups. Many of these examples may not be done directly using integrated semigroups.