## Kavli IPMU Komaba Seminar

開催情報 月曜日　16:30～18:00　数理科学研究科棟(駒場) 002号室 河野 俊丈

### 2014年01月30日(木)

17:00-18:30   数理科学研究科棟(駒場) 128号室
Hans Jockers 氏 (The University of Bonn)
Characteristic classes from 2d renormalized sigma-models (ENGLISH)
[ 講演概要 ]
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.