dorsal/arxiv
View SchemaA note on the scatteredness of reflection orders
| Authors | Weijia Wang, Rui Wang |
|---|---|
| Categories | |
| ArXiv ID | 2601.09275vv1 |
| URL | https://arxiv.org/abs/2601.09275 |
| License | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
Abstract
In this note, we characterize affine Coxeter systems among all Coxeter systems in terms of the structure of their reflection orders. For an infinite irreducible system $(W,S)$, we show that affineness is equivalently characterized by the scatteredness of all reflection orders, by the existence of a reflection order of type $\omega+\omega^*$, and by a finiteness property of intervals determined by dihedral reflection subgroups. Our proof exploits the geometry of projective roots, the isotropic cone and the universal reflection subgroups in an infinite non-affine Coxeter group.
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"abstract": "In this note, we characterize affine Coxeter systems among all Coxeter systems in terms of the structure of their reflection orders. For an infinite irreducible system $(W,S)$, we show that affineness is equivalently characterized by the scatteredness of all reflection orders, by the existence of a reflection order of type $\\omega+\\omega^*$, and by a finiteness property of intervals determined by dihedral reflection subgroups. Our proof exploits the geometry of projective roots, the isotropic cone and the universal reflection subgroups in an infinite non-affine Coxeter group.",
"arxiv_id": "2601.09275",
"authors": [
"Weijia Wang",
"Rui Wang"
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"math.GR"
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"license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
"title": "A note on the scatteredness of reflection orders",
"url": "https://arxiv.org/abs/2601.09275",
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