Weil-Petersson volumes, stability conditions and wall-crossing

Abstract: In this paper we study Weil-Petersson volumes of the moduli spaces of conical hyperbolic surfaces. The moduli spaces are parametrised by their cone angles which naturally live inside Hassett's space of stability conditions on nodal curves. Such stability conditions produce weighted pointed stable curves which define compactifications of the moduli space of curves generalising the Deligne-Mumford compactification. The space of stability conditions decompose into chambers separated by walls. We assign to each chamber a polynomial corresponding to the Weil-Petersson volume of a moduli space of conical hyperbolic surfaces. The chambers are naturally partially ordered and the maximal chamber is assigned Mirzakhani's polynomial. We calculate wall-crossing polynomials, which relates the polynomial on any chamber to Mirzakhani's polynomial via wall-crossings, and we show how to apply this in particular cases. Since the polynomials are volumes, they have nice properties such as positivity, continuity across walls, and vanishing in certain limits.