Answer by nfdc23 for Rational Characters of a reductive group have the same...
The following is a mild and perhaps too-detailed variant on David Loeffler's answer. To adhere to Borel's textbook notation, I will write $X_F(G)$ for what you denote by $X(G)_F$ and will write...
View ArticleAnswer by David Loeffler for Rational Characters of a reductive group have...
This is much easier than it looks. The point is that any reductive group $G$ is isogenous to the product of its radical, which is its centre $Z(G)$, and its commutator subgroup, which is a semisimple...
View ArticleRational Characters of a reductive group have the same rank as split component
Let $G$ be a connected reductive group defined over a perfect field $F$. The split component $A$ of $G$ is the unique maximal $F$-split subtorus of the radical of $G$. For an algebraic group $H$ over...
View Article
More Pages to Explore .....
