#### Volume 16, issue 3 (2016)

 Recent Issues
 The Journal About the Journal Editorial Board Editorial Interests Editorial Procedure Submission Guidelines Submission Page Subscriptions Author Index To Appear Contacts ISSN (electronic): 1472-2739 ISSN (print): 1472-2747
The homotopy types of $\mathrm{PU}(3)$– and $\mathrm{PSp}(2)$–gauge groups

### Sho Hasui, Daisuke Kishimoto, Akira Kono and Takashi Sato

Algebraic & Geometric Topology 16 (2016) 1813–1825
##### Abstract

Let $G$ be a compact connected simple Lie group. Any principal $G$–bundle over ${S}^{4}$ is classified by an integer $k\in ℤ\cong {\pi }_{3}\left(G\right)$, and we denote the corresponding gauge group by ${\mathsc{G}}_{k}\left(G\right)$. We prove that ${\mathsc{G}}_{k}\left(PU\left(3\right)\right)\simeq {\mathsc{G}}_{\ell }\left(PU\left(3\right)\right)$ if and only if $\left(24,k\right)=\left(24,\ell \right)$, and ${\mathsc{G}}_{k}\left(PSp\left(2\right)\right){\simeq }_{\left(p\right)}{\mathsc{G}}_{\ell }\left(PSp\left(2\right)\right)$ for any prime $p$ if and only if $\left(40,k\right)=\left(40,\ell \right)$, where $\left(m,n\right)$ is the gcd of integers $m,n$.

##### Keywords
gauge group, Samelson product
Primary: 55P35
Secondary: 55Q15
##### Publication
Received: 23 June 2015
Revised: 29 September 2015
Accepted: 11 December 2015
Published: 1 July 2016
##### Authors
 Sho Hasui Department of Mathematics Kyoto University Kyoto 606-8502 Japan Daisuke Kishimoto Department of Mathematics Kyoto University Kyoto 606-8502 Japan Akira Kono Department of Mathematical Science, Faculty of Science and Engineering Doshisha University Kyoto 610-0394 Japan Takashi Sato Department of Mathematics Kyoto University Kyoto 606-8502 Japan