Communications in Number Theory and Physics

Volume 3 (2009)

Number 3

Superconformal algebras and mock theta functions 2: Rademacher expansion for K3 surface

Pages: 531 – 554



Tohru Eguchi (Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan)

Kazuhiro Hikami (Department of Mathematics, Naruto University of Education, Tokushima, Japan)


The elliptic genera of the K3 surfaces, both compact andnon-compact cases, are studied by using the theory of mocktheta functions. We decompose the elliptic genus in termsof the $\mathcal{N}=4$ superconformal characters atlevel-$1$, and present an exact formula for thecoefficients of the massive (non-BPS) representations usingPoincaré–Maass series.

Published 1 January 2009