Covers counting via Feynman Calculus
arXiv:1204.2480
Abstract
Let be a finite group. In this paper we present a tool for counting the number of principle -bundles over a surface. As an application, we express (non-standard) generating functions for double Hurwitz numbers as integrals over commutative Frobenius algebras, associated with symmetric groups.
15 pages, 5 figures