Knowledge of an analytic group implies knowledge of its module category.
However complete knowledge of the category does not determine the group.
Professor Magid shows here that the category determines another, larger
group and an algebra of functions in this new group. The new group and
its function algebra are completely described; this description thus
tells everything that is known when the module category, as a category,
is given. This categorical view brings together and highlights the
significance of earlier work in this area by several authors, as well as
yielding new results. By including many examples and computations
Professor Magid has written a complete account of the subject that is
accessible to a wide audience. Graduate students and professionals who
have some knowledge of algebraic groups, Lie groups and Lie algebras
will find this a useful and interesting text.