Multiplicative invariant theory, as a research area in its own right within the wider spectrum of invariant theory, is of relatively recent vintage. The present text offers a coherent account of the basic results achieved thus far..
Multiplicative invariant theory is intimately tied to integral representations of finite groups. Therefore, the field has a predominantly discrete, algebraic flavor. Geometry, specifically the theory of algebraic groups, enters through Weyl groups and their root lattices as well as via character lattices of algebraic tori.
Throughout the text, numerous explicit examples of multiplicative invariant algebras and fields are presented, including the complete list of all multiplicative invariant algebras for lattices of rank 2.
The book is intended for graduate and postgraduate students as well as researchers in integral representation theory, commutative algebra and, mostly, invariant theory.
Encyclopaedia of Mathematical Sciences Volume 135 Invariant Theory and Algebraic Transformation Groups VI Subseries Editors: R.V. Gamkrelidze V.L. Popov Martin Lorenz Multiplicative Invariant Theory 123 Author Martin Lorenz Department of Mathematics Temple University Philadelphia, PA 19122, USA e-mail:
[email protected] Founding editor of the Encyclopaedia of Mathematical Sciences: R. V. Gamkrelidze Mathematics Subject Classification (2000): Primary: 13A50 Secondary: 13H10, 13D45, 20C10, 12F20 ISSN 0938-0396 ISBN 3-540-24323-2 Springer Berlin Heidelberg New York This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reu