Grad Student Colloquium

Benjamin Anderson-Sackaney, Department of Pure Mathematics, University of Waterloo

"Honeycombs and the Horn Problem"

We will talk about the main ideas behind the proof of Horn's Conjecture, the resolution of an eigenvalue problem posed by Hermann Weyl in 1912, conjectured by Alfred Horn in 1962. Allen Knutson and Terrence Tao  proved Horn's conjecture in 1999 by settling another open problem, namely, the saturation conjecture, a statement about so called Littlewood-Richardson coefficients. The key turned out to be Honeycomb models, a combinatorial object developed to study Littlewood-Richardson coefficients. We will discuss Honeycomb models and roughly how they were used to resolve the Horn conjecture.

MC 5501