Equations of the moduli of pointed curves in the infinite Grassmannian

Abstract

The main result of this paper is the explicit computation of the equations defining the moduli space of triples $(C,p,z)$ (where $C$ is an integral and complete algebraic curve, $p$ a smooth rational point and $z$ a formal trivialization around $p$) in the infinite Grassmannian of $k((t))$. This is achieved by introducing infinite Grassmannians, tau and Baker-Ahkiezer functions algebraically and by proving an Addition Formula for tau functions.