33 citations · 227 across the 59 of their papers we have counts for
74 papers
Equivariantly normal varieties for diagonalizable group actions
Michel Brion
Given a finite group scheme over a field and a -variety , we obtain a criterion for to be -normal in the sense of \cite{Br24}. When is diagonalizable, we descr…
Minimal rational curves on complete symmetric varieties
Michel Brion, Shin-young Kim, Nicolas Perrin
We describe the families of minimal rational curves on any complete symmetric variety, and the corresponding varieties of minimal rational tangents (VMRT). In particular, we prove…
Actions of finite group schemes on curves
Michel Brion
Every action of a finite group scheme on a variety admits a projective equivariant model, but not necessarily a normal one. As a remedy, we introduce and explore the notion of…
The inverse Galois problem for connected algebraic groups
Michel Brion, Stefan Schröer
We show that each connected group scheme of finite type over an arbitrary ground field is isomorphic to the component of the identity inside the automorphism group scheme of some p…
On models of algebraic group actions
Michel Brion
We show that every action of a smooth algebraic group on a variety admits a normal projective model. Along the way, we present new proofs of some basic results on algebraic transfo…
Abelian varieties as automorphism groups of smooth projective varieties in arbitrary characteristics
Jérémy Blanc, Michel Brion
Let be an abelian variety over an algebraically closed field. We show that is the automorphism group scheme of some smooth projective variety if and only if has only fi…