An action of the Polishchuk differential operator via punctured surfaces

Abstract

For a family of Jacobians of smooth pointed curves there is a notion of tautological algebra. There is an action of ${\mathfrak{sl}}_2$ on this algebra. We define and study a lifting of the Polishchuk operator, corresponding to $f\in {\mathfrak{sl}}_2$, on an algebra consisting of punctured Riemann surfaces. As an application we prove that a collection of tautological relations on moduli of curves, discovered by Faber and Zagier, come from a class of relations on the universal Jacobian.

37 pages