# Sarah Trebat-Leder

Affiliation: Emory University

Email: sarahtrebatleder@gmail.com

Title Of Talk: A new moonshine for the Mathieu group $M_{23}$

Abstract: We show that for the Matthieu group $M_{23}$, there exists an infinite-dimensional graded module $M$ such that the graded trace of $g \in M_{23}$ acting on $M$ is, up to the constant term, identical to a monstrous moonshine McKay-Thompson series. This new moonshine comes from Matthieu moonshine, but is significantly simpler, as the functions involved are modular of weight 0 on genus zero subgroups instead of mock modular of weight 1/2.