ABSTRACT
In this appendix we recall the definitions and the main properties of strongly continuous and analytic semigroups that we use in this book. If not otherwise specified, we refer the reader to [51, 72, 104, 123] for the proofs of the results of this appendix. To begin with we give the definition of semigroup of bounded linear oper-
ators. Throughout this appendix, if not otherwise specified, X will denote a Banach space.
