Landau-Ginzburg Orbifolds and Symmetries of K3 CFTs

Understand

Recent developments in the study of the moonshine phenomenon, including umbral and Conway moonshine, suggest that it may play an important role in encoding the action of finite symmetry groups on the BPS spectrum of K3 string theory.

• To test and clarify these proposed K3-moonshine connections, we study Landau-Ginzburg orbifolds that flow to conformal field theories in the moduli space of K3 sigma models.
• We compute K3 elliptic genera twined by discrete symmetries that are manifest in the UV description, though often inaccessible in the IR.
• We obtain various twining functions coinciding with moonshine predictions that have not been observed in physical theories before.