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arXiv · 1301.1118

An Enriques involution of a supersingular K3 surface over odd characteristic

Junmyeong Jang
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Abstract

In this paper, we prove, as the complex case, a supersingular K3 surface over a field of odd characteristic has an Enriques involution if and only if there exists a primitive embedding of the twice of the Enriques lattice into the Neron-Severi group such that the orthogonal complement of the embedding has no vector of self-intersection -2 using the Crystalline Torelli theorem. By this criterion and some lattice calculation, we prove that when the characteristic of the base field is p=19 or p>23, a superingular K3 surface is an Enriques K3 surface if and only if the Artin invariant is less than 6.

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Junmyeong Jang. 2013-01-14. An Enriques involution of a supersingular K3 surface over odd characteristic. https://arxiv.org/abs/1301.1118

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