English

Homotopy Normal Maps

Algebraic Topology 2015-07-16 v9

Abstract

Normal maps between discrete groups NGN\rightarrow G were characterized [FS] as those which induce a compatible topological group structure on the homotopy quotient EN×NGEN\times_N G. Here we deal with topological group (or loop) maps NGN\rightarrow G being normal in the same sense as above and hence forming a homotopical analogue to the inclusion of a topological normal subgroup in a reasonable way. We characterize these maps by a compatible simplicial loop space structure on Bar(N,G)Bar_\bullet(N,G), invariant under homotopy monoidal functors, e.g. Localizations and Completions. In the course of characterizing homotopy normality, we define a notion of a "homotopy action" similar to an AA_{\infty} action on a space, but phrased in terms of Segal's 'special Δ\Delta-spaces' and seem to be of importance on its own right. As an application of the invariance of normal maps, we give a very short proof to a theorem of Dwyer and Farjoun namely that a localization by a suspended map of a principal fibration of connected spaces is again principal.

Keywords

Cite

@article{arxiv.1011.4708,
  title  = {Homotopy Normal Maps},
  author = {Matan Prasma},
  journal= {arXiv preprint arXiv:1011.4708},
  year   = {2015}
}

Comments

This paper appeared under "Matan Prezma"; later papers of the author appear under "Matan Prasma"

R2 v1 2026-06-21T16:46:58.300Z