On numerically trivial automorphisms of threefolds of general type

Zhi Jiang; Wenfei Liu; Hang Zhao

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arXiv · 2103.15626

On numerically trivial automorphisms of threefolds of general type

Zhi Jiang·Wenfei Liu·Hang Zhao

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Abstract

In this paper, we prove that the group $\mathrm{Aut}_\mathbb{Q}(X)$ of numerically trivial automorphisms are uniformly bounded for smooth projective threefolds $X$ of general type which either satisfy $q(X)\geq 3$ or have a Gorenstein minimal model. If $X$ is furthermore of maximal Albanese dimension, then $|\mathrm{Aut}_\mathbb{Q}(X)|\leq 4$, and equality can be achieved by an unbounded family of threefolds previously constructed by the third author. Along the way we prove a Noether type inequality for log canonical pairs of general type with the coefficients of the boundary divisor from a given subset $\mathcal{C}\subset (0,1]$ such that $\mathcal{C}\cup\{1\}$ attains the minimum.

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Zhi Jiang, Wenfei Liu, Hang Zhao. 2021-03-29. On numerically trivial automorphisms of threefolds of general type. https://arxiv.org/abs/2103.15626

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