Quasi-F-splittings in birational geometry III

TL;DR

This paper establishes a connection between quasi-$F$-regular singularities and klt singularities in birational geometry, introducing quasi-test ideals to facilitate the proof.

Contribution

It proves that $Q$-Gorenstein quasi-$F$-regular singularities are klt and introduces quasi-test ideals as a new tool.

Findings

$Q$-Gorenstein quasi-$F$-regular singularities are klt

Introduction of quasi-test ideals

Advances understanding of singularities in birational geometry

Abstract

We prove that $\mathbb Q$-Gorenstein quasi-$F$-regular singularities are klt. To this end, we shall introduce quasi-test ideals.