Zero-cycles on Moduli Spaces of Twisted Sheaves and Applications to Double EPW Quartics

TL;DR

This paper extends results on zero-cycles from untwisted to twisted K3 surface moduli spaces, linking them to double EPW quartics and Verra fourfolds, and compares their Beauville--Voisin classes.

Contribution

It generalizes zero-cycle results to twisted K3 surfaces and connects these to double EPW quartics and Verra fourfolds.

Findings

Effective zero-cycles agree if and only if they agree in the associated Verra fourfold.

The twisted Beauville--Voisin class matches the Beauville--Voisin class in the studied case.

Abstract

Chen, Li, Zhang, and Zhang extended the results of Shen, Yin, and Zhao on zero-cycles on moduli spaces of stable objects on $K3$ surfaces to the twisted setting. In this work, we complement this by extending results by Vial and Martin--Vial to moduli spaces on twisted $K3$ surfaces. Exploiting the fact that double EPW quartics can be realised as moduli spaces of twisted sheaves, we show that effective zero-cycles agree if and only if they agree in the associated Verra fourfold and show that the twisted Beauville--Voisin class of Chen, Li, Zhang, and Zhang agrees with the Beauville--Voisin class in that case.