Event time:
Tuesday, April 17, 2018 - 4:30pm to 5:30pm
Speaker:
Theo Johnson-Freyd
Speaker affiliation:
Perimeter Institute
Event description:
Whenever a finite group G acts on a 2dquantum field theory, it determines a ``gauge anomaly'' living in the fourth integral group cohomology of G. I will describe what I know about H4 for certain sporadic groups, focusing on the most charismatic ones: the Monster and Conway's largest group. In particular, I will suggest thatoften H4(G) is cyclic and generated by the gauge anomaly of a distinguished ``moonshine'' representation of G.