English

Bridgeland Moduli spaces for Gushel-Mukai threefolds and Kuznetsov's Fano threefold conjecture

Algebraic Geometry 2021-08-30 v2

Abstract

We study the Hilbert scheme H\mathcal{H} of twisted cubics on a special smooth Gushel-Mukai threefolds X10X_{10}. We show that it is a smooth irreducible projective threefold if X10X_{10} is general among special Gushel-Mukai threefolds, while it is singular if X10X_{10} is not general. We construct an irreducible component of a moduli space of Bridgeland stable objects in the Kuznetsov component of X10X_{10} as a divisorial contraction of H\mathcal{H}. We also identify the minimal model of Fano surface C(X10)\mathcal{C}(X_{10}') of conics on a smooth ordinary Gushel-Mukai threefold with moduli space of Bridgeland stable objects in the Kuznetsov component of X10X_{10}'. As a result, we show that the Kuznetsov's Fano threefold conjecture is not true

Keywords

Cite

@article{arxiv.2012.12193,
  title  = {Bridgeland Moduli spaces for Gushel-Mukai threefolds and Kuznetsov's Fano threefold conjecture},
  author = {Shizhuo Zhang},
  journal= {arXiv preprint arXiv:2012.12193},
  year   = {2021}
}

Comments

35 pages, substantially rewritten, remove everything irrelevant. Fix typos and correct mistakes on computations, prove stronger results via Serre-invariant stability conditions