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Take a compact connected simple centreless Lie group $G$. Can the commutator map $G\times G\to G$ sending $(x,y)$ to $[x,y]$ be homotopic to a constant map?

I am interested mostly in the case, where $G={\rm PSU}(n)$.

As far as I understand, the commutator map is homologically trivial (right?).

There is a related question.

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1 Answer 1

up vote 7 down vote accepted

The following is the main theorem in

Araki, S.; James, I. M.; Thomas, E., "Homotopy-abelian Lie groups", Bull. Amer. Math. Soc. 1960.

Theorem: A compact connected Lie group is homotopy-abelian only if it is abelian.

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Thank you, Ramiro, this is what I sought! –  Anton Klyachko Oct 31 '13 at 17:02

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