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    • CommentRowNumber1.
    • CommentAuthorAli Caglayan
    • CommentTimeOct 12th 2018
    • (edited Oct 12th 2018)

    Start of Eilenberg-MacLane space article.

    Naming of the constructors is not really ideal, but I don’t like the ones in the original paper. The recursion principle is there it may need some more explaining. I have neglected the induction principle for now.

    Also I have made GG an arbitary group, yet the construction of higher EM-spaces require it to be abelian. Given the definition of the higher EM-spaces I don’t see what is stopping it from being non-abelian. I would guess that K(G,2)K(G,2) would have π 2\pi_2 as the abelianisation of GG. Which may be interesting.

    v1, current

    • CommentRowNumber2.
    • CommentAuthorMike Shulman
    • CommentTimeOct 12th 2018

    Yes, if you write down the construction of “K(G,n)K(G,n)” for nonabelian GG, then you should end up with K(G ab,n)K(G_{ab},n) when n>1n\gt 1. Given the construction K(G,2)=ΣK(G,1) 2K(G,2) = \Vert \Sigma K(G,1) \Vert_2, this should be a special case of the Hurewicz theorem.

    • CommentRowNumber3.
    • CommentAuthorAli Caglayan
    • CommentTimeOct 12th 2018

    @Mike Do you know if anybody has written down a proof of Hurewicz in HoTT yet? Even if it’s on an evelope?

    • CommentRowNumber4.
    • CommentAuthorMike Shulman
    • CommentTimeOct 13th 2018

    I don’t think so.