RIND seminar on Mathematical Physics and String Theory

June 20, 2022 at 4 p.m. only via Zoom

Ilka Brunner (LMU München)
Nils Carqueville (Universität Wien)
Hans Jockers (JGU Mainz)
Peter Mayr (LMU München)
Simone Noja (Universität Heidelberg)
Ivo Sachs (LMU München)
Johannes Walcher (Universität Heidelberg)

Joint seminar series on Mathematical Physics and String Theory

Path integral derivations of K-theoretic Donaldson invariants
Heeyeon Kim (Rutgers U.)

We discuss path integral derivations of topologically twisted partition functions of 5d SU(2) supersymmetric Yang-Mills theory on M4 x S1, where M4 is a smooth closed four-manifold. Mathematically, they can be identified with the K-theoretic version of the Donaldson invariants. In particular, we provide two different path integral derivations of their wall-crossing formula for b_2^+(M4)=1, first in the so-called U-plane integral approach, and in the perspective of instanton counting. We briefly discuss the generalization to b_2^+(M4)>1.