Sylow Criteria for Liftability of Automorphism Groups of Smooth Hypersurfaces

Abstract

In this paper, we first establish Sylow criteria for liftability of finite subgroups of the projective linear groups over arbitrary field. We also obtain Sylow criteria for $F$-liftability: if $F$ is a nonsingular polynomial of degree $d$ in $N$ variables over a field of characteristic zero, then a finite subgroup $G$ of $\mathrm{Lin}(F)$ is $F$-liftable if and only if for every prime $p$ dividing $\gcd (|G|,N,d)$, there exists a Sylow $p$-subgroup of $G$ that is $F$-liftable. Our proof combines restriction and corestriction in group cohomology with the reduction-to-Klein method.

15 pages. Comments welcome!