Time: 9h00, Wednesday, June 8, 2016
Location: Room 6, Building A14, Institute of Mathematics, 18 Hoang Quoc Viet, Cau Giay, Hanoi
Abstract: Let $G$ be an algebraic group defined over a field $k$, and let $H$ be a $k$-subgroup. We say that $H$ is an epimorphic subgroup of $G$ if every morphism $f:G to G'$ is uniquely determined by its restriction on $H$. In the case of smooth connected affine algebraic groups over an algebraically closed field, this notion has been studied and used for investigating the rational connected varieties by Borel-Bien (1992), Borel-Bien-Kollar (1996). Also, some rationality properties of epimorphic subgroups was obtained by N. Q. Thang-B. (2005). In this talk, I present some recent results given by M. Brion regarding epimorphic subgroups in the setting of algebraic group schemes.