# MathCS Seminar

Title: Vector-valued Hirzebruch-Zagier series and class number sums
Seminar: Algebra
Speaker: Brandon Williams of UC Berkeley
Contact: David Zureick-Brown, dzb@mathcs.emory.edu
Date: 2018-04-17 at 4:00PM
Venue: W304
Abstract:
For any fundamental discriminant $D > 0$, Hirzebruch and Zagier constructed a modular form of weight two whose Fourier coefficients are corrections of the Hurwitz class number sums $\sum_{r^2 \equiv 4n \, (D)} H((4n - r^2) / D)$. In this talk, we will discuss how one can reinterpret their result and remove the condition that $D$ is fundamental by working instead with vector-valued modular forms for Weil representations.