English

Height four formal groups with quadratic complex multiplication

Algebraic Topology 2021-11-10 v1 Number Theory

Abstract

We construct spectral sequences for computing the cohomology of automorphism groups of formal groups with complex multiplication by a pp-adic number ring. We then compute the cohomology of the group of automorphisms of a height four formal group law which commute with complex multiplication by the ring of integers in the field Qp(p)\mathbb{Q}_p(\sqrt{p}), for primes p>5p>5. This is a large subgroup of the height four strict Morava stabilizer group. The group cohomology of this group of automorphisms turns out to have cohomological dimension 88 and total rank 8080. We then run the K(4)K(4)-local E4E_4-Adams spectral sequence to compute the homotopy groups of the homotopy fixed-point spectrum of this group's action on the Lubin-Tate/Morava spectrum E4E_4.

Keywords

Cite

@article{arxiv.1607.04113,
  title  = {Height four formal groups with quadratic complex multiplication},
  author = {A. Salch},
  journal= {arXiv preprint arXiv:1607.04113},
  year   = {2021}
}

Comments

arXiv admin note: text overlap with arXiv:1607.01108

R2 v1 2026-06-22T14:54:38.273Z