GIT stable cubic threefolds and certain fourfolds of $K3^{[2]}$-type
Abstract
We study the behaviour on some nodal hyperplanes of the isomorphism, described in a paper of 2019 by Boissi\`ere, Camere and Sarti, between the moduli space of smooth cubic threefolds and the moduli space of hyperk\"ahler fourfolds of -type with a non-symplectic automorphism of order three, whose invariant lattice has rank one and is generated by a class of square 6; along those hyperplanes the automorphism degenerates by jumping to another family. We generalize their result to singular nodal cubic threefolds having one singularity of type for providing birational maps between the loci of cubic threefolds where a generic element has an isolated singularity of the types and some moduli spaces of hyperk\"ahler fourfolds of -type with non-symplectic automorphism of order three belonging to different families. In order to treat the case, we introduce the notion of K\"ahler cone sections of -type generalizing the definition of -general polarized hyperk\"ahler manifolds.
Cite
@article{arxiv.2301.11149,
title = {GIT stable cubic threefolds and certain fourfolds of $K3^{[2]}$-type},
author = {Lucas Li Bassi},
journal= {arXiv preprint arXiv:2301.11149},
year = {2025}
}
Comments
Second version, minor changes