English

On the image of the unstable Boardman map

Algebraic Topology 2019-06-14 v2

Abstract

We consider the `unstable Boardman map' (homomorphism if k>0k>0) b:πm+kΣkΩlSn+l[ΩlSn+l,ΩkSm+k]Hom(HΩlSn+l,HΩkSm+k)b:\pi^{m+k}\Sigma^k\Omega^lS^{n+l}\simeq[\Omega^lS^{n+l},\Omega^kS^{m+k}]\longrightarrow \mathrm{Hom}(H_*\Omega^lS^{n+l},H_*\Omega^kS^{m+k}) defined by h(f)=fh(f)=f_*. We work at the prime 22, with k=0k=0, and determine the image for various in the following cases : (1) m=nm=n and l>0l>0 arbitrary; (2) m>nm>n and l=1l=1. We observe that in most of the cases the image is trivial with the exceptions corresponding to the cases when either there is a (commutative) HH-space structure on SnS^n or there is a Hopf invariant one element.

Keywords

Cite

@article{arxiv.1806.07079,
  title  = {On the image of the unstable Boardman map},
  author = {Hadi Zare},
  journal= {arXiv preprint arXiv:1806.07079},
  year   = {2019}
}

Comments

This is an update, with an updated title, to an older arxiv post with this identifier as a note on `cospherical' classes

R2 v1 2026-06-23T02:34:17.449Z