English

On The Telescopic Picard Group

Algebraic Topology 2024-12-16 v3 Category Theory

Abstract

We prove that for any prime pp and height n1n \ge 1, the telescopic Picard group Pic(SpTn)\mathrm{Pic}(\mathrm{Sp}_{Tn}) contains a subgroup of the form Zp×Z/ap(pn1)\mathbb{Z}_p \times \mathbb{Z}/a_p(p^n-1), where ap=1a_p = 1 if p=2p = 2 and ap=2a_p = 2 if pp is odd. Using Kummer theory, we obtain an (Fpn×Z/n)(\mathbb{F}_{p^n}^\times \rtimes \mathbb{Z}/n)-Galois extension of ST(n)\mathbb{S}_{T(n)}, obtaining the first example of a lift of a non-Abelian Galois extension of the K(n)K(n)-local sphere to the telescopic world, at arbitrary positive height and prime. Our proof proceeds by setting up a higher categorical framework for the periodicity theorem, utilizing the symmetries of this framework to construct Picard elements.

Keywords

Cite

@article{arxiv.2412.07716,
  title  = {On The Telescopic Picard Group},
  author = {Shai Keidar},
  journal= {arXiv preprint arXiv:2412.07716},
  year   = {2024}
}

Comments

57 pages, comments are welcome!

R2 v1 2026-06-28T20:29:48.607Z