Timeline for Simply connected algebraic groups and reductive subgroups of maximal rank

11 events

when toggle format	what		by	license	comment
May 1, 2013 at 0:24	answer	added	Jeffrey Adams		timeline score: 3
Apr 13, 2013 at 23:03	comment	added	Jim Humphreys		P.S. I finally got around to looking again at the 1949 paper by Borel and de Siebenthal on compact Lie groups. Though I remembered their algorithm and table, which carry over to root systems in algebraic settings, I had completely forgotten their useful Remarque II. I'm not quite sure whether it applies readily to algebraic groups, especially in prime characteristic, but it shortcuts some fundamental group questions (still leaving perhaps a case-free question).
Apr 13, 2013 at 13:03	vote	accept	Jim Humphreys
Apr 13, 2013 at 13:03	history	edited	Jim Humphreys	CC BY-SA 3.0	added 1046 characters in body
Apr 7, 2013 at 20:17	history	edited	Jim Humphreys	CC BY-SA 3.0	added 2 characters in body
Apr 7, 2013 at 13:29	history	edited	Jim Humphreys	CC BY-SA 3.0	added 695 characters in body
Apr 5, 2013 at 20:00	answer	added	Paul Levy		timeline score: 5
Apr 4, 2013 at 19:28	answer	added	Allen Knutson		timeline score: 2
Apr 4, 2013 at 16:40	answer	added	Marc van Leeuwen		timeline score: 1
Apr 4, 2013 at 16:15	comment	added	Misha		Jim: I do not know an answer but one approach would be to look at Dynkin et al classification of maximal subgroups of G. Either you would find a counter example or you can induct. This is a bit unsatisfactory since it requires case-by-case analysis especially in the exceptional cases.
Apr 4, 2013 at 13:47	history	asked	Jim Humphreys	CC BY-SA 3.0