English

Some remarks on Brauer Classes of K3-type

Algebraic Geometry 2024-05-31 v1

Abstract

An element in the Brauer group of a general complex projective K3K3 surface SS defines a sublattice of the transcendental lattice of SS. We consider those elements of prime order for which this sublattice is Hodge-isometric to the transcendental lattice of another K3 surface XX. We recall that this defines a finite map between moduli spaces of polarized K3 surfaces and we compute its degree. We show how the Picard lattice of XX determines the Picard lattice of SS in the case that the Picard number of XX is two.

Keywords

Cite

@article{arxiv.2405.19848,
  title  = {Some remarks on Brauer Classes of K3-type},
  author = {Federica Galluzzi and Bert van Geemen},
  journal= {arXiv preprint arXiv:2405.19848},
  year   = {2024}
}

Comments

16 pages, submitted to Rendiconti Semin. Mat. Univ.Politecn. Torino, volume dedicated to the memory of Gianfranco Casnati