Tensor decompositions for SL(2) and outerplanar graphs

Aleksandrs Mihailovs
Department of Mathematics
University of Pennsylvania
Philadelphia, PA 19104-6395
http://www.math.upenn.edu/~mihailov/

The main result of this article is the decomposition of tensor products 
of representations of SL(2) in the sum of irreducible representations 
parametrized by outerplanar graphs. 
An outerplanar graph is a graph with the vertices 0, 1, 2, ..., m, 
edges of which can be drawn in the upper half-plane without intersections. 
I allow for a graph to have multiple edges, but don't allow loops. 

Submitted to the Journal of Combinatorial Theory, Series A.