Skip to main content
13 events
when toggle format what by license comment
Jul 23, 2012 at 16:02 comment added Paul Reynolds A search of the literature indicates that while $\pi_2G = 0$ does follow from Bott's work in Milnor's book, it was in fact proved by E.Cartan in 1911 before Bott was even born.
Jul 22, 2012 at 7:20 history edited Kerry CC BY-SA 3.0
added 12 characters in body
Jul 22, 2012 at 7:19 comment added Kerry I am really embarrassed, my memory is not accurate; the papers asked whether $\pi_{1}G$ is free instead. Sorry for raisng the wrong question at here.
Jul 22, 2012 at 5:06 answer added Zhaoting Wei timeline score: 6
Jul 22, 2012 at 4:55 comment added Mariano Suárez-Álvarez Can you list couple of examples of papers which use the hypothesis that $\pi_2G\neq0$?
Jul 22, 2012 at 4:51 comment added Mariano Suárez-Álvarez The vanishing of $\pi_2$ was discussed at least once in MO: google might be of help finding the thread, which was very enlightening!
Jul 22, 2012 at 2:50 history edited Kerry CC BY-SA 3.0
added 46 characters in body
Jul 22, 2012 at 2:27 comment added Kerry You mean simple ones, or any? I did read Bott's collective papers but never seen this theorem. I shall check the link.
Jul 22, 2012 at 2:25 comment added Akhil Mathew Incidentally, $\pi_2 G = 0$ for any Lie group; this is a theorem of Bott. See mathoverflow.net/questions/8957/homotopy-groups-of-lie-groups for a very nice discussion or Milnor's book "Morse Theory."
Jul 22, 2012 at 2:21 comment added Kerry I see the problem, corrected.
Jul 22, 2012 at 2:21 history edited Kerry CC BY-SA 3.0
added 1 characters in body; added 25 characters in body
Jul 22, 2012 at 2:17 comment added Will Sawin Is that symplectic group supposed to have an even dimension?
Jul 22, 2012 at 2:12 history asked Kerry CC BY-SA 3.0