Special isogenies and tensor product multiplicities
Representation Theory
2007-06-18 v1 Algebraic Geometry
Abstract
We show that any bijection between two root systems that preserves angles (but not necessarily lengths) gives rise to inequalities relating tensor product multiplicities for the corresponding complex semisimple Lie groups (or Lie algebras). We explain the inequalities in two ways: combinatorially, using Littelmann's Path Model, and geometrically, using isogenies between algebaric groups defined over an algebraically closed field of positive characteristic.
Cite
@article{arxiv.0706.2324,
title = {Special isogenies and tensor product multiplicities},
author = {Shrawan Kumar and John R. Stembridge},
journal= {arXiv preprint arXiv:0706.2324},
year = {2007}
}