English

A note on the second James-Hopf invariant

Algebraic Topology 2026-06-28 v1

Abstract

This paper characterizes the stabilized second James-Hopf invariant by means of three axioms. Specifically, we show that it is the unique natural transformation satisfying the Cartan formula, vanishing on suspensions, and a metastable EHP property. The proof combines the natural stable splitting of the James construction with Goodwillie calculus.

Cite

@article{arxiv.2606.29486,
  title  = {A note on the second James-Hopf invariant},
  author = {John R. Klein},
  journal= {arXiv preprint arXiv:2606.29486},
  year   = {2026}
}