Supersingular K3 Surfaces are Unirational
arXiv:1304.5623
Abstract
We show that supersingular K3 surfaces in characteristic are related sequences of very special correspondences. This is not enough to conclude that they are unirational. As a byproduct, we exhibit a fibration structure on the moduli space of rigidified K3 crystals. We also establish Shioda-Inose type isogeny theorems for K3 surfaces with Picard rank in positive characteristic.
due to a mistake in Proposition 3.5, the unirationality of supersingular K3 surfaces remains a conjecture: see the appendix for erratum