Dimension Formulae in Genus Zero and Uniqueness of Vertex Operator Algebras

Jethro van Ekeren, Sven Möller, Nils R. Scheithauer

We prove a dimension formula for orbifold vertex operator algebras of central charge 24 by automorphisms of order $n$ such that ${\Gamma }_0(n)$ is a genus zero group. We then use this for…