Kavli IPMU Komaba Seminar

Speaker: Hans Jockers (The University of Bonn)
Title: Characteristic classes from 2d renormalized sigma-models
Date (JST): Thu, Jan 30, 2014, 17:00 - 18:30
Place: Room 128, Mathematical Sciences Building, Komaba Campus, The University of Tokyo
Abstract: The Hirzebruch-Riemann-Roch formula relates the holomorphic Euler characteristic of holomorphic vector bundles to topological invariants of compact complex manifold. I will explain a generalization of the Mukai's modified first Chern character map, which introduces certain characteristic classes that have not been considered in this form by Hirzebruch. This naturally leads to the characteristic Gamma class based on the Gamma function. The characteristic Gamma class has a surprising relation to the quantum theory of certain 2d sigma-models with compact complex manifolds as their target spaces. I will argue that the Gamma class describes perturbative quantum corrections to the classical theory of those sigma models.