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The classification of 2-compact groups

Andersen, Kasper LU orcid and Grodal, Jesper (2009) In Journal of the American Mathematical Society 22(2). p.387-436
Abstract
We prove that any connected 2-compact group is classified by its

2-adic root datum, and in particular the exotic 2-compact group

DI(4), constructed by Dwyer-Wilkerson, is the only simple 2-compact group not arising as the 2-completion of a compact connected Lie group. Combined with our earlier work with Møller and Viruel for p odd, this establishes the full classification of p-compact groups, stating that, up to isomorphism, there is a one-to-one correspondence between connected p-compact groups and root data over the p-adic integers. As a consequence we prove the maximal torus conjecture, giving a one-to-one correspondence between compact Lie groups and finite loop spaces admitting a maximal torus. Our proof is a general... (More)
We prove that any connected 2-compact group is classified by its

2-adic root datum, and in particular the exotic 2-compact group

DI(4), constructed by Dwyer-Wilkerson, is the only simple 2-compact group not arising as the 2-completion of a compact connected Lie group. Combined with our earlier work with Møller and Viruel for p odd, this establishes the full classification of p-compact groups, stating that, up to isomorphism, there is a one-to-one correspondence between connected p-compact groups and root data over the p-adic integers. As a consequence we prove the maximal torus conjecture, giving a one-to-one correspondence between compact Lie groups and finite loop spaces admitting a maximal torus. Our proof is a general induction on the dimension of the group, which works for all primes. It refines the Andersen-Grodal-Møller-Viruel methods by incorporating the theory of root data over the p-adic integers, as developed by Dwyer-Wilkerson and the authors. Furthermore we devise a different way of dealing with the rigidification problem by utilizing obstruction groups calculated by Jackowski-McClure-Oliver in the early 1990s. (Less)
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author
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publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Mathematical Society
volume
22
issue
2
pages
387 - 436
publisher
American Mathematical Society (AMS)
external identifiers
  • scopus:77950582963
ISSN
0894-0347
DOI
10.1090/S0894-0347-08-00623-1
language
English
LU publication?
no
id
3060e347-5d28-46ed-a329-17800df38bc9 (old id 3412526)
alternative location
http://www.ams.org/journals/jams/2009-22-02/S0894-0347-08-00623-1/
date added to LUP
2016-04-01 12:30:06
date last changed
2022-03-29 01:46:24
@article{3060e347-5d28-46ed-a329-17800df38bc9,
  abstract     = {{We prove that any connected 2-compact group is classified by its<br/><br>
2-adic root datum, and in particular the exotic 2-compact group<br/><br>
DI(4), constructed by Dwyer-Wilkerson, is the only simple 2-compact group not arising as the 2-completion of a compact connected Lie group. Combined with our earlier work with Møller and Viruel for p odd, this establishes the full classification of p-compact groups, stating that, up to isomorphism, there is a one-to-one correspondence between connected p-compact groups and root data over the p-adic integers. As a consequence we prove the maximal torus conjecture, giving a one-to-one correspondence between compact Lie groups and finite loop spaces admitting a maximal torus. Our proof is a general induction on the dimension of the group, which works for all primes. It refines the Andersen-Grodal-Møller-Viruel methods by incorporating the theory of root data over the p-adic integers, as developed by Dwyer-Wilkerson and the authors. Furthermore we devise a different way of dealing with the rigidification problem by utilizing obstruction groups calculated by Jackowski-McClure-Oliver in the early 1990s.}},
  author       = {{Andersen, Kasper and Grodal, Jesper}},
  issn         = {{0894-0347}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{387--436}},
  publisher    = {{American Mathematical Society (AMS)}},
  series       = {{Journal of the American Mathematical Society}},
  title        = {{The classification of 2-compact groups}},
  url          = {{http://dx.doi.org/10.1090/S0894-0347-08-00623-1}},
  doi          = {{10.1090/S0894-0347-08-00623-1}},
  volume       = {{22}},
  year         = {{2009}},
}