Skip to main content
7 events
when toggle format what by license comment
Apr 26, 2011 at 1:25 comment added Tom Goodwillie I think you can use a subgroup of $PSL(4,\mathbb Z)$ that is conjugate in $PSL(4,\mathbb R)$ to a subgroup of $PSO(4)\cong SO(3)\times SO(3)$ that is isomorphic to $A_4\times A_4$.
Apr 25, 2011 at 15:25 comment added Jim Humphreys This is definitely a creative approach, though I still wonder whether something more conceptual (in a more general context of arithmetic groups) is possible. Also, I wonder what an efficient subgroup choice would be for $n=4$?
Apr 25, 2011 at 15:21 comment added Jim Humphreys Rather than add this as an answer it would be preferable just to accept Tom's answer.
Apr 25, 2011 at 1:51 history edited Tom Goodwillie CC BY-SA 3.0
added 3 characters in body; deleted 8 characters in body
Apr 24, 2011 at 18:23 history edited Tom Goodwillie CC BY-SA 3.0
deleted 7 characters in body
Apr 24, 2011 at 15:39 comment added John Franks Thanks Tom. I was, of course, only interested in the n even case. Your answer definitively answers the question for my purposes.
Apr 24, 2011 at 13:03 history answered Tom Goodwillie CC BY-SA 3.0