Weierstrass mock modular forms and certain VOAs

Using techniques from the theory of mock modular forms and harmonic Maaß forms, especially Weierstrass mock modular forms,
we establish several dimension formulas for certain holomorphic, strongly rational vertex operator algebras, complementing previous
work by van Ekeren, Möller, and Scheithauer. As an application, we show that certain special values of the completed Weierstrass zeta
function are rational. This talk is based on joint work with Lea Beneish.