We derive presentations of the interval groups related to all quasi-Coxeter elements in the Coxeter group of type . Type is the only infinite family of finite Coxeter groups that admits proper quasi-Coxeter elements. The presentations we obtain are over a set of generators in bijection with what we call a Carter generating set, and the relations are those defined by the related Carter diagram together with a twisted cycle or a cycle commutator relator, depending on whether the quasi-Coxeter element is a Coxeter element or not. The proof is based on the description of two combinatorial techniques related to the intervals of quasi-Coxeter elements.
In a subsequent work [4], we complete our analysis to cover all the exceptional cases of finite Coxeter groups, and establish that almost all the interval groups related to proper quasi-Coxeter elements are not isomorphic to the related Artin groups, hence establishing a new family of interval groups with nice presentations [4, 5]. Alongside the proof of the main results, we establish important properties related to the dual approach to Coxeter and Artin groups.
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Keywords: Coxeter groups, Quasi-Coxeter elements, Carter diagrams, Artin(–Tits) groups, dual approach to Coxeter and Artin groups, generalised non-crossing partitions, Garside structures, Interval (Garside) structures.
Baumeister, Barbara 1; Neaime, Georges 2; Rees, Sarah 3
@article{ALCO_2023__6_2_471_0, author = {Baumeister, Barbara and Neaime, Georges and Rees, Sarah}, title = {Interval groups related to finite {Coxeter} groups {I}}, journal = {Algebraic Combinatorics}, pages = {471--506}, publisher = {The Combinatorics Consortium}, volume = {6}, number = {2}, year = {2023}, doi = {10.5802/alco.266}, language = {en}, url = {https://alco.centre-mersenne.org/articles/10.5802/alco.266/} }
TY - JOUR AU - Baumeister, Barbara AU - Neaime, Georges AU - Rees, Sarah TI - Interval groups related to finite Coxeter groups I JO - Algebraic Combinatorics PY - 2023 SP - 471 EP - 506 VL - 6 IS - 2 PB - The Combinatorics Consortium UR - https://alco.centre-mersenne.org/articles/10.5802/alco.266/ DO - 10.5802/alco.266 LA - en ID - ALCO_2023__6_2_471_0 ER -
%0 Journal Article %A Baumeister, Barbara %A Neaime, Georges %A Rees, Sarah %T Interval groups related to finite Coxeter groups I %J Algebraic Combinatorics %D 2023 %P 471-506 %V 6 %N 2 %I The Combinatorics Consortium %U https://alco.centre-mersenne.org/articles/10.5802/alco.266/ %R 10.5802/alco.266 %G en %F ALCO_2023__6_2_471_0
Baumeister, Barbara; Neaime, Georges; Rees, Sarah. Interval groups related to finite Coxeter groups I. Algebraic Combinatorics, Volume 6 (2023) no. 2, pp. 471-506. doi : 10.5802/alco.266. https://alco.centre-mersenne.org/articles/10.5802/alco.266/
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