Stephen Hardy (UVa)
A short history and proof of Lin's theorem
Are almost commuting self-adjoint matrices near commuting self-adjoint matrices? This question, introduced in the 1960s and championed by mathematicians such as Halmos, was finally satisfactorily answered in 1994 by Huaxin Lin. We will briefly explore the history of this and related approximation problems, and sketch the elementary proof of this remarkable result due to Friis and Rordam.