Black Holes and Hurwitz Class Numbers
arXiv:1705.06295 · doi:10.1142/S0218271817420032
Abstract
We define a natural counting function for BPS black holes in $K3 \times T^2$ compactification of type II string theory, and observe that it is given by a weight 3/2 mock modular form discovered by Zagier. This hints at tantalizing relations connecting black holes, string theory, and number theory.
6 pages, essay awarded third prize in the Gravity Research Foundation 2017 essay competition