Genus $g$ Virasoro Correlation Functions for Vertex Operator Algebras
Michael P. Tuite, Michael Welby
TL;DR
The paper provides a genus $g$ framework for Virasoro $n$-point functions of VOAs using Schottky uniformisation and genus $g$ Zhu recursion. It constructs an explicit order-$n$ differential operator $\mathcal{D}_n(\mathbf{z})$ that acts on the normalised partition function $\Theta_V=Z_V Z_M^{-c}$ to yield the Virasoro $n$-point generating function, expressing $\mathcal{D}_n$ as a sum over Virasoro graphs with weights depending on the central charge $c$, the classical differential geometry on the surface (bidifferential, projective connection, holomorphic forms), and derivatives with respect to $3g-3$ period matrix elements. The weights are organized so that $\mathcal{D}_n$ captures Virasoro vacuum descendant correlators and obeys a precise recursive structure, with a first-principles derivation of the Ward identities and a detailed account of modular properties under homology base changes. This work links VOA correlation functions at genus $g$ to the differential geometry of moduli space, enabling modular differential equations and graph-based formulations of high-genus Virasoro correlators.
Abstract
For a simple, self-dual, strong CFT-type vertex operator algebra (VOA) of central charge $c$, we describe the Virasoro $n$-point correlation function on a genus $g$ marked Riemann surface in the Schottky uniformisation. We show that this $n$-point function determines the correlation functions for all Virasoro vacuum descendants. Using our recent work on genus $g$ Zhu recursion, we show that the Virasoro $n$-point function is determined by a differential operator $\mathcal{D}_{n}$ acting on the genus $g$ VOA partition function normalised by the Heisenberg partition function to the power of $c$. We express $\mathcal{D}_{n}$ as the sum of weights over certain Virasoro graphs where the weights explicitly depend on $c$, the classical bidifferential of the second kind, the projective connection, holomorphic 1-forms and derivatives with respect to any $3g-3$ locally independent period matrix elements. We also describe the modular properties of $\mathcal{D}_{n}$ under a homology base change.
