Rational cubic fourfolds with associated singular K3 surfaces
arXiv:2004.08446
Abstract
Generalizing a recent construction of Yang and Yu, we study to what extent one can intersect Hassett's Noether-Lefschetz divisors in the moduli space of cubic fourfolds . In particular, we exhibit arithmetic conditions on 20 indexes that assure that the divisors all intersect one another. This allows us to produce examples of rational cubic fourfolds with an associated K3 surface with rank 20 Néron-Severi group, i.e. a singular K3 surface.
14 pages