# Rational Singularities for Moment Maps of Totally Negative Quivers

## TL;DR

This paper proves that the zero-fiber of the moment map of a totally negative quiver has rational singularities and explores its implications in arithmetic geometry.

## Contribution

The paper introduces a generalization of jet space dimension bounds and applies them to prove rational singularities in quiver moment maps.

## Key findings

- The zero-fiber of the moment map of a totally negative quiver has rational singularities.
- The rational singularities property is extended to moduli spaces in 2-Calabi-Yau categories.
- Jet counts over finite fields are connected to p-adic volumes of moduli spaces.

## Abstract

We prove that the zero-fiber of the moment map of a totally negative quiver has rational singularities. Our proof consists in generalizing dimension bounds on jet spaces of this fiber, which were introduced by Budur. We also transfer the rational singularities property to other moduli spaces of objects in 2-Calabi-Yau categories, based on recent work of Davison. This has interesting arithmetic applications on quiver moment maps and moduli spaces of objects in 2-Calabi-Yau categories. First, we generalize results of Wyss on the asymptotic behaviour of counts of jets of quiver moment maps over finite fields. Moreover, we interpret the limit of counts of jets on a given moduli space as its p-adic volume under a canonical measure analogous to the measure built by Carocci, Orecchia and Wyss on certain moduli spaces of coherent sheaves.