Skip to main content
9 events
when toggle format what by license comment
Sep 26, 2013 at 21:58 answer added Little Lie Theory timeline score: 0
Sep 25, 2013 at 16:24 comment added Marguax I should have added that the final sentence of the 2nd paragraph is false. The finite simple group $A_5$ has a 3-dimensional representation in characteristic 0 which can be "reduced mod $p$" to give a (faithful) representation into ${\rm{SL}}_3(k)$ for finite fields $k$ with sufficiently large characteristic $r$, thereby making $A_5$ an $r'$-subgroup. But the Weyl group of ${\rm{SL}}_3$ is $S_3$, so the $r'$-subgroup $A_5$ cannot lie inside the normalizer of any maximal torus.
Sep 25, 2013 at 15:37 answer added Jim Humphreys timeline score: 1
Sep 25, 2013 at 14:07 comment added Marguax The condition that $K$ includes only semisimple elements is the same as the condition that the order of $K$ is prime to $r$, in view of the $\mathbf{F}_q$-rational Jordan decomposition and the existence of Sylow subgroups of finite groups. So the first sentence of your 3rd paragraph (phrased as a question) seems to be repeating the last sentence of your 2nd paragraph (not phrased as a question). Please clarify what you are asking for.
S Sep 25, 2013 at 12:29 history suggested Asaf CC BY-SA 3.0
Latexed the mathematical expressions in the question
Sep 25, 2013 at 12:06 review Suggested edits
S Sep 25, 2013 at 12:29
Sep 25, 2013 at 10:27 comment added José Figueroa-O'Farrill You can use LaTeX on this site by simply surrounding the mathematical expressions with dollar signs!
Sep 25, 2013 at 9:25 review First posts
Sep 25, 2013 at 9:25
Sep 25, 2013 at 9:06 history asked Little Lie Theory CC BY-SA 3.0