English

K3 surfaces associated to a cubic fourfold

Algebraic Geometry 2024-05-21 v2

Abstract

Let X5X\subset \P^5 be a smooth cubic fourfold. A well known conjecture asserts that XX is rational if and only if there an Hodge theoretically associated K3 surface SS. The surface SS can be associated to XX in two other different ways. If there is an equivalence of categories \sAXDb(S,α)\sA_X \simeq D^b(S,\alpha) where \sAX\sA_X is the Kuznetsov component of Db(X)D^b(X) and α\alpha is a Brauer class, or if there is an isomorphism between the transcendental motive t(X)t(X) and the (twisted ) transcendental motive of a K3 surfaceSS. In this note we consider families of cubic fourfolds with a finite group of automorphisms and describe the cases where there is an associated K3 surface in one of the above senses.

Keywords

Cite

@article{arxiv.2405.05074,
  title  = {K3 surfaces associated to a cubic fourfold},
  author = {Claudio Pedrini},
  journal= {arXiv preprint arXiv:2405.05074},
  year   = {2024}
}

Comments

23 pages Revised version.Added new results and more references

R2 v1 2026-06-28T16:20:47.752Z