RTGC Seminar: Orbifolds of conformal field theories and cohomology of sporadic groups

Seminar | April 14 | 4-5:30 p.m. | 939 Evans Hall

 Theo Johnson-Freyd, Perimeter Institute

 Department of Mathematics

I will report on work in progress to understand the fourth integral cohomology of the two most famous sporadic finite groups: the Fischer–Griess Monster and Conway's group Co0. These cohomology classes arise when studying orbifolds of conformal field theories; in that world, they are called "anomalies". I will explain the connection between fermionic anomalies and "string structures" on representations. I will also describe how to move information about anomalies through orbifolds.