Timeline for About structure of parabolic subgroups of finite classical algebraic groups

4 events

when toggle format	what		by	license	comment
Mar 22, 2014 at 14:27	comment	added	Will Sawin		I think we can verify explicitly that this is true for classical groups. For $SL_n$, the Levi looks like $SL_a \times SL_b$ for $a+b=n$ and $U$ is just Homs from the standard representation of $SL_a$ to the standard representation of $SL_b$. For $SO_n$ the Levi is $Gl_a \times SO_{n-2a}$, and $U$ is an extension of homs between the standard representations by $\wedge^2$ of $GL_a$, with the second one the center unless the first is $0$. Same thing with $SP_{2n}$ and $\operatorname{Sym}^2$.
Mar 22, 2014 at 1:54	history	edited	Nick Gill	CC BY-SA 3.0	added 181 characters in body
Mar 21, 2014 at 21:19	history	edited	Nick Gill	CC BY-SA 3.0	added 282 characters in body
Mar 21, 2014 at 20:03	history	answered	Nick Gill	CC BY-SA 3.0