research

Moonshine in Fivebrane Spacetimes

Abstract

We consider type II superstring theory on K3×S1×R1,4K3 \times S^1 \times \mathbb{R}^{1,4} and study perturbative BPS states in the near-horizon background of two Neveu-Schwarz fivebranes whose world-volume wraps the K3×S1K3 \times S^1 factor. These states are counted by the spacetime helicity supertrace χ2(τ)\chi_2(\tau) which we evaluate. We find a simple expression for χ2(τ)\chi_2(\tau) in terms of the completion of the mock modular form H(2)(τ)H^{(2)}(\tau) that has appeared recently in studies of the decomposition of the elliptic genus of K3 surfaces into characters of the N=4 superconformal algebra and which manifests a moonshine connection to the Mathieu group M24M_{24}.Comment: 32 page

    Similar works