Department colloquium - Bernd Sturmfels

Title: The Geometry of Gaussoids

Speaker: Bernd Sturmfels. Director of the Max Planck Institute for Mathematics in the Sciences, Leipzig 

Abstract:  Gaussoids offer a new link between combinatorics, statistics and algebraic geometry. Introduced by Lnenicka and Matus in 2007, their axioms describe conditional independence for Gaussian random variables. We explain this theory and how it relates to matroids. The role of the Grassmannian for matroids is now played by a projection of the Lagrangian Grassmannian. We discuss the classification and realizability of gaussoids, and we explore oriented gaussoids, valuated gaussoids, and the analogue to positroids. This is joint work with Tobias Boege, Alessio D'Ali and Thomas Kahle.