DIAMETERS OF GRAPHS OF REDUCED WORDS AND RANK-TWO ROOT SUBSYSTEMS

We study the diameter of the graph G(w) of reduced words of an element w in a Coxeter group W whose edges correspond to applications of the Coxeter relations. We resolve conjectures of Reiner-Roichman [Trans. Amer. Math. Soc. 365 (2013), pp. 2279-2802] and Dahlberg-Kim [Diameters of graphs on reduce...

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Bibliographic Details
Main Authors: Gaetz, C. (Author), Gao, Y. (Author)
Format: Article
Language:English
Published: American Mathematical Society 2022
Online Access:View Fulltext in Publisher
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Summary:We study the diameter of the graph G(w) of reduced words of an element w in a Coxeter group W whose edges correspond to applications of the Coxeter relations. We resolve conjectures of Reiner-Roichman [Trans. Amer. Math. Soc. 365 (2013), pp. 2279-2802] and Dahlberg-Kim [Diameters of graphs on reduced words of 12 and 21-inflations, arXiv:2010.15758, 2020] by proving a tight lower bound on this diameter when W = Sn is the symmetric group and by characterizing the equality cases. We also give partial results in other classical types which illustrate the limits of current techniques. © 2022 American Mathematical Society.
ISBN:00029939 (ISSN)
DOI:10.1090/proc/15912