Timeline for What are the outer automorphisms of a Coxeter group?
Current License: CC BY-SA 3.0
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| Dec 6, 2014 at 2:56 | comment | added | John Baez | Thanks! If we think of the Coxeter group concretely as transformations of $\mathbb{R}^8$, the only central element is $x \mapsto -x$. Then this outer automorphism must be $w \mapsto \det(w) w$: i.e., it does nothing to even products of reflections through roots, and multiplies odd products by $-1$. Sound right? | |
| Dec 5, 2014 at 19:16 | history | edited | Qiaochu Yuan | CC BY-SA 3.0 |
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| Dec 5, 2014 at 19:04 | history | edited | Qiaochu Yuan | CC BY-SA 3.0 |
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| Dec 5, 2014 at 18:54 | history | answered | Qiaochu Yuan | CC BY-SA 3.0 |