DMS Linear Algebra/Algebra Seminar

Speaker: Justin Chen, GA Tech

Title: The 4x4 orthostochastic variety

Abstract: A real matrix is called orthostochastic if it is the entrywise square of an orthogonal matrix. These matrices have been shown to be deeply connected to determinantal representations of polynomials, and also arise naturally in physics. However, the equations defining the real variety are known only up to the 3x3 case. I will outline a theorem* which gives set-theoretic equations for the 4x4 orthostochastic variety, using techniques of numerical algebraic geometry.

Based on joint work with Papri Dey.