Maximal commutative unipotent subgroups and a characterization of affine spherical varieties

Andriy Regeta, Immanuel van Santen

We describe maximal commutative unipotent subgroups of the automorphism group $\mathrm{Aut}(X)$ of an irreducible affine variety $X$. Further we show that a group isomorphism $\mat…