Not signed in (Sign In)

Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

  • Sign in using OpenID

Site Tag Cloud

2-category 2-category-theory abelian-categories adjoint algebra algebraic algebraic-geometry algebraic-topology analysis analytic-geometry arithmetic arithmetic-geometry book bundles calculus categorical categories category category-theory chern-weil-theory cohesion cohesive-homotopy-type-theory cohomology colimits combinatorics complex complex-geometry computable-mathematics computer-science constructive cosmology definitions deformation-theory descent diagrams differential differential-cohomology differential-equations differential-geometry digraphs duality elliptic-cohomology enriched fibration foundation foundations functional-analysis functor gauge-theory gebra geometric-quantization geometry graph graphs gravity grothendieck group group-theory harmonic-analysis higher higher-algebra higher-category-theory higher-differential-geometry higher-geometry higher-lie-theory higher-topos-theory homological homological-algebra homotopy homotopy-theory homotopy-type-theory index-theory integration integration-theory k-theory lie-theory limits linear linear-algebra locale localization logic mathematics measure-theory modal modal-logic model model-category-theory monad monads monoidal monoidal-category-theory morphism motives motivic-cohomology nlab noncommutative noncommutative-geometry number-theory object of operads operator operator-algebra order-theory pages pasting philosophy physics pro-object probability probability-theory quantization quantum quantum-field quantum-field-theory quantum-mechanics quantum-physics quantum-theory question representation representation-theory riemannian-geometry scheme schemes set set-theory sheaf simplicial space spin-geometry stable-homotopy-theory stack string string-theory superalgebra supergeometry svg symplectic-geometry synthetic-differential-geometry terminology theory topology topos topos-theory tqft type type-theory universal variational-calculus

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to nForum
If you want to take part in these discussions either sign in now (if you have an account), apply for one now (if you don't).
    • 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.