This monograph provides a systematic treatment of the
abstract theory of adjoint semigroups. After presenting the
basic elementary results, the following topics are treated
in detail: The sigma (X, X )-topology, -reflexivity, the
Favard class, Hille-Yosida operators, interpolation and
extrapolation, weak -continuous semigroups, the codimension
of X in X , adjoint semigroups and the Radon-Nikodym
property, tensor products of semigroups and duality,
positive semigroups and multiplication semigroups.
The major part of the material is reasonably self-contained
and is accessible to anyone with basic knowledge of semi-
group theory and Banach space theory. Most of the results
are proved in detail. The book is addressed primarily to
researchers working in semigroup theory, but in view of the
"Banach space theory" flavour of many of the results, it
will also be of interest to Banach space geometers and
operator theorists.

The adjoint semigroup.- The ?(X,X?)-topology.- Interpolation, extrapolation and duality.- Perturbation theory.- Dichotomy theorems.- Adjoint semigroups and the RNP.- Tensor products.- The adjoint of a positive semigroup.