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Apr 22, 2011 at 11:06 vote accept Honglu
Apr 22, 2011 at 11:06 vote accept Honglu
Apr 22, 2011 at 11:06
Apr 21, 2011 at 9:14 comment added Honglu I'm not able to judge. But if it is said to be right, I will accept this. I hope after finishing Hatcher and some references I would be able to read it.
Apr 21, 2011 at 7:36 history edited Oscar Randal-Williams CC BY-SA 3.0
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Apr 21, 2011 at 3:37 comment added Dylan Wilson You'd need the space to be simple (i.e. the action of $\pi_1$ to be trivial on higher homotopy groups) in order to apply the homology version of Whitehead here.
Apr 21, 2011 at 2:38 comment added Tom Goodwillie Wait a minute: The relative Hurewicz Theorem is not that strong. A map inducing isomorphisms on $\pi_1$ and $H_n$ for all $n$ need not be a weak equivalence.
Apr 21, 2011 at 1:47 comment added Honglu Why does a homology equivalence plus a $\pi_1$ lead to weak homotopy equivalence?
Apr 20, 2011 at 14:35 comment added Tom Goodwillie You mean, because the loopspace is not quite a group? but there are ways of rectifying that, for example Kan's Quillen adjunction between simplicial groups and reduced simplicial sets.
Apr 20, 2011 at 14:09 comment added Oscar Randal-Williams They won't typically be equivalent to classifying spaces of actual groups, though.
Apr 20, 2011 at 13:55 comment added Tom Goodwillie Or instead of using topological groups that are either abelian or discrete, you can use more general ones and say that $M$ and $N$ themselves are equivalent to classifying spaces, and do it that way. This is if they are connected. If they are not, then it is false.
Apr 20, 2011 at 13:48 history answered Oscar Randal-Williams CC BY-SA 3.0