Time：12:00-13:45, Thursday, Oct 6, 2022
ZOOM ID: 845 2669 4139
PASSCODE: 616988
Host: Dr. Xing Gu, Institute for Theoretical Sciences, Westlake University
Speaker：Prof. Christian Haesemeyer, University of Melbourne
Biography: Christian Haesemeyer is a Professor of mathematics at the University of Melbourne. His research is in algebraic K-theory. He has worked on K-theory of singularities, on motives and algebraic cycles, and in motivic homotopy theory. Most recently, he has become interested in t-structures on derived categories of schemes.
Title：Diagonalising matrices, vector bundles, and K-theory of algebraic singularities
Abstract: It is a basic fact from linear algebra that a real or complex matrix A such that A^2 = A is diagonalisable. If we allow the entries of the matrix to be functions on some space instead of scalars, then this is no longer true in general. In this talk, we will explain how this algebraic question relates to the geometry and topology of the space. In the second part, we will explain how modern methods from algebraic K-theory allow us to solve an old problem about the (stable) diagonalisability of idempotent matrices over certain rings of functions on algebraic singularities. This is joint work with G. Cortinas, M. E. Walker, and C. Weibel.
