English

A computation of $THH_*(ku)$ using a gathered spectral sequence

Algebraic Topology 2026-05-19 v2 K-Theory and Homology

Abstract

In this article, we extend the computation of topological Hochschild homology (THH) of the Adams summand \ell of pp-local connective complex topological K-theory (kuku) to kuku itself. We leverage the relation up1=v1u^{p-1} = v_1, where uu is a generator of kuku_* and v1v_1 is a generator of \ell_*, and we consider the cofiber of the multiplication by v1v_1 in kuku, denoted ku/v1ku/v_1. We use the morphism between the Bockstein spectral sequences of the multiplication by v1v_1 computing THH()THH_*(\ell) and THH(ku)THH_*(ku); we develop a general technique using what we term a gathered spectral sequence that allows us to explore the relationship between the Bockstein spectral sequences for the multiplications by v1v_1 and uu, from which we derive a complete computation of THH(ku)THH_*(ku). Our method is not only applicable to this specific problem but may also prove useful in other computations.

Keywords

Cite

@article{arxiv.2511.02346,
  title  = {A computation of $THH_*(ku)$ using a gathered spectral sequence},
  author = {Maxime Chaminadour},
  journal= {arXiv preprint arXiv:2511.02346},
  year   = {2026}
}

Comments

41 pages; revised the argument for the torsion-free extensions at the beginning of section 5.3; improved the presentation

R2 v1 2026-07-01T07:20:47.756Z