Flexibility of Affine cones over Mukai fourfolds of genus $g\ge 7$

Abstract

We show that the affine cones over a general Fano-Mukai fourfold of genus $g=7$, $8$ and $9$ are flexible. Equivalently, there is an infinitely transitive action of the special automorphism group on such affine cones. In particular, any Mukai fourfold of genus $7,8$ and $9$ is ${\mathbb{A}}^2$-cylindrical.

18 pages. Comments welcome!