English

THH(Z) and the image of J

Algebraic Topology 2025-05-06 v1 Algebraic Geometry K-Theory and Homology

Abstract

Let pp be an odd prime number and jp\mathrm{j}_p the pp-complete connective image of J spectrum. We establish an equivalence of cyclotomic E\mathbb{E}_\infty-rings THH(Z)psh(jptriv)\mathrm{THH}(\mathbb{Z})^{\wedge}_p \simeq \mathrm{sh}(\mathrm{j}_p^{\mathrm{triv}}) and an equivalence of E\mathbb{E}_\infty-rings TP(Z)pjptS1\mathrm{TP}(\mathbb{Z})^{\wedge}_p \simeq \mathrm{j}_p^{\mathrm{t}\mathrm{S}^1}. We also record a few applications of this: a new perspective, with some new information, on the description of TC(Z)p\mathrm{TC}(\mathbb{Z})^{\wedge}_p as a spectrum; height 11 analogues of the fiber squares of Antieau-Mathew-Morrow-Nikolaus, resulting in new calculations in K(1)\mathrm{K}(1)-localized algebraic K-theory; and a proof of a slight refinement of the noncommutative crystalline-de Rham comparison result of Petrov-Vologodsky.

Keywords

Cite

@article{arxiv.2505.02218,
  title  = {THH(Z) and the image of J},
  author = {Sanath K. Devalapurkar and Arpon Raksit},
  journal= {arXiv preprint arXiv:2505.02218},
  year   = {2025}
}