Umbral Moonshine and Niemeier Lattices

Seminar: 
Number Theory
Event time: 
Tuesday, September 24, 2013 - 12:30pm to Monday, September 23, 2013 - 8:00pm
Location: 
LOM 205
Speaker: 
Miranda Cheng
Speaker affiliation: 
Institut de Mathematiques de Jussieu, Paris
Event description: 

In this talk I will discuss a new type of moonshine phenomenon relating mock modular forms and finite groups. The construction of this umbral moonshine is based on the 23 even, unimodular rank 24 Niemeier lattices with non-trivial root systems. I will also comment on the relation between umbral moonshine and Hauptmoduls of genus zero groups. The talk will be based on joint work with John Duncan and Jeff Harvey.