Commuting Matrices: Algebra and Geometry

Al Sethuraman
Department of Mathematics, California State University, Northridge

Abstract: A classical theorem of Gerstenhaber and Motskin-Taussky states that the dimension of the algebra generated by a pair of commuting n x n matrices is at most n. We study the geometry underlying the proof and discuss the status of the following open problem: is the dimension of the algebra generated by a triple of commuting n x n matrices also bounded by n? Along the way, we will discuss algebraic varieties, the Zariski topology, irreducible components, and related wondrous beasts.