SMS scnews item created by Kevin Coulembier at Wed 6 Mar 2019 1108
Type: Seminar
Distribution: World
Expiry: 27 Mar 2019
Calendar1: 13 Mar 2019 1200-1300
CalLoc1: Carslaw 375
CalTitle1: Honeycombs, polytopes, and orbital measures: another look at representation theory
Auth: kevinc@pkevinc.pc (assumed)

Algebra Seminar: Coquereaux -- Honeycombs, polytopes, and orbital measures: another look at representation theory

Robert Coquereaux (Aix-Marseille Universite) 

Wednesday 13 March, 12-1pm, Place: Carslaw 375 

Title: Honeycombs, polytopes, and orbital measures: another look at representation
theory.  

Abstract: Several combinatorial models (pictographs) can be used to determine the
multiplicities (Littlewood - Richardson coefficients) of those irreducible
representations (irreps) that occur in the reduction of a product of two irreps of the
Lie group SU(n).  Such pictographs can be considered as the integer points of an
associated polytope whose volume can be expressed in terms of the Fourier transform of a
convolution product of orbital measures.  After describing several variants of this
construction, we discuss a few properties of the volume function, whose definition makes
sense in a wider context.