International Journal of Mathematics and Mathematical Sciences
Volume 2006 (2006), Article ID 48274, 22 pages

Invariant triple products

Anton Deitmar

Mathematisches Institut, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 10, Tübingen 72076, Germany

Received 18 May 2005; Revised 26 June 2006; Accepted 5 July 2006

Copyright © 2006 Anton Deitmar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


It is shown that the space of invariant trilinear forms on smooth representations of a semisimple Lie group is finite dimensional if the group is a product of hyperbolic groups. Explicit upper bounds are given which are attained in the case of induced representations. Applications to automorphic coefficients are given.