Bøger af Sigurdur Helgason

The first edition of this book has been out of print for some time and I have decided to follow the publisher's kind suggestion to prepare a new edition. Here 5 provides proofs of the needed results about the Riesz potentials while 3-4 develop the tools from Fourier analysis following closely the account in Hormander's books (1963] and [1983].

Integral geometry is a fascinating area where numerous branches of mathematics meet together. This book is concentrated around the duality and double fibration, which is realized through the masterful treatment of a variety of examples.

The Radon transform is an important topic in integral geometry which deals with the problem of expressing a function on a manifold in terms of its integrals over certain submanifolds. Readers will find here an accessible introduction to Radon transform theory, an elegant topic in integral geometry.

This is a collection of essays taken from a conference: three of them deal with various aspects of integral geometry, with a common emphasis on several kinds of Radon transforms, their properties and applications, the other two share stress on CR manifolds and related problems.

Suitable as a text for both Riemannian geometry and for the analysis and geometry of symmetric spaces, this title features chapters on differential geometry and Lie groups. It also includes a chapter on functions on symmetric spaces, that gives an introduction to the study of spherical functions, and the theory of invariant differential operators.