Deformations of elliptic fibre bundles in positive characteristic
arXiv:1005.2142 · doi:10.1215/00277630-2141608
Abstract
We study deformation theory of elliptic fibre bundles over curves in positive characteristics. As applications, we give examples of non-liftable elliptic surfaces in charactertic two and three, which answers a question of Katsura and Ueno. Also, we construct a class of elliptic fibrations, whose liftability is equivalent to a conjecture of F. Oort concerning the liftability of automorphisms of curves. Finally, we classify deformations of bielliptic surfaces.
Many typos fixed (thanks to the referee). Minor improvements in presentation