Abstract
We consider three notions of connectivity and their interactions in partially ordered sets coming from reduced factorizations of an element in a generated group. While one form of connectivity essentially reflects the connectivity of the poset diagram, the other two are a bit more involved: Hurwitz-connectivity has its origins in algebraic geometry, and shellability in topology. We propose a framework to study these connectivity properties in a uniform way. Our main tool is a certain linear order of the generators that is compatible with the chosen element.
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We thank the anonymous referee for the many comments and suggestions that helped improve both content and exposition of this paper.
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HM is partially supported by a Public Grant overseen by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” Program (Reference: ANR-10-LABX-0098) and by Digiteo project PAAGT (Nr. 2015-3161D). VR is supported by the Austrian Science Foundation FWF, Grants Z130-N13 and F50-N15, the latter in the framework of the Special Research Program “Algorithmic and Enumerative Combinatorics”.
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Mühle, H., Ripoll, V. Connectivity Properties of Factorization Posets in Generated Groups. Order 37, 115–149 (2020). https://doi.org/10.1007/s11083-019-09496-1
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DOI: https://doi.org/10.1007/s11083-019-09496-1