Tyrrell McAllister (TU Eindhoven): Applications of polyhedral geometry to computational representation theory

We discuss several families of polyhedra that arise in the representation theory of semisimple Lie algebras. In the past 10 years, work by Berenstein and Zelevinsky and by Knutson and Tao has shown the fruitfulness of encoding coefficients related to the decompositions of representations as the number of lattice points contained in special families of polytopes. We discuss in particular applications of polytopes to the computational complexity of Clebsch--Gordan coefficients. We also mention some conjectures and results motivated by the polytopal interpretation of these coefficients.