On disc-with-hole and disc-with-handle partition functions in bosonic string theory

Abstract: Higher genus partition functions of string world sheets with boundaries are relevant, e.g. for computation of quantum corrections to Wilson loop expectation values. As a preparation for a possible study of strings in curved space like AdS here we consider examples of genus one partition functions of string world-sheets ending on a circle in the bosonic string theory in flat space. We begin with the partition function for annular topology, writing it as an integral over the modulus of the annulus. In the process, we compute the determinant of the Laplacian on the annulus for Dirichlet-Dirichlet and Dirichlet-Neumann boundary conditions. We then consider the case of the disc-with-handle topology using the gluing method. We first write the partition function using a Schottky parameterisation of the moduli space and then as an integral over the period matrix.