Complete reducibility of subgroups of reductive algebraic groups over nonperfect fields IV: An $F_4$ example

Falk Bannuscher, Alastair Litterick, Tomohiro Uchiyama

Let $k$ be a nonperfect separably closed field. Let $G$ be a connected reductive algebraic group defined over $k$. We study rationality problems for Serre's notion of complete redu…