Flip cycles in plabic graphs

Abstract Planar bicolored (plabic) graphs are combinatorial objects introduced by Postnikov to give parameterizations of the positroid cells of the totally nonnegative Grassmannian $$\text {Gr}^{\ge 0}(n,k)$$Gr≥0(n,k). Any two plabic graphs for the same positroid cell can be related by a sequence o...

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Main Authors: Balitskiy, Alexey, Wellman, Julian
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Springer International Publishing 2021
Online Access:https://hdl.handle.net/1721.1/131399
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author Balitskiy, Alexey
Wellman, Julian
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Balitskiy, Alexey
Wellman, Julian
author_sort Balitskiy, Alexey
collection MIT
description Abstract Planar bicolored (plabic) graphs are combinatorial objects introduced by Postnikov to give parameterizations of the positroid cells of the totally nonnegative Grassmannian $$\text {Gr}^{\ge 0}(n,k)$$Gr≥0(n,k). Any two plabic graphs for the same positroid cell can be related by a sequence of certain moves. The flip graph has plabic graphs as vertices and has edges connecting the plabic graphs which are related by a single move. A recent result of Galashin shows that plabic graphs can be seen as cross-sections of zonotopal tilings for the cyclic zonotope Z(n, 3). Taking this perspective, we show that the fundamental group of the flip graph is generated by cycles of length 4, 5, and 10, and use this result to prove a related conjecture of Dylan Thurston about triple crossing diagrams. We also apply our result to make progress on an instance of the generalized Baues problem.
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spelling mit-1721.1/1313992023-10-06T20:14:10Z Flip cycles in plabic graphs Balitskiy, Alexey Wellman, Julian Massachusetts Institute of Technology. Department of Mathematics Abstract Planar bicolored (plabic) graphs are combinatorial objects introduced by Postnikov to give parameterizations of the positroid cells of the totally nonnegative Grassmannian $$\text {Gr}^{\ge 0}(n,k)$$Gr≥0(n,k). Any two plabic graphs for the same positroid cell can be related by a sequence of certain moves. The flip graph has plabic graphs as vertices and has edges connecting the plabic graphs which are related by a single move. A recent result of Galashin shows that plabic graphs can be seen as cross-sections of zonotopal tilings for the cyclic zonotope Z(n, 3). Taking this perspective, we show that the fundamental group of the flip graph is generated by cycles of length 4, 5, and 10, and use this result to prove a related conjecture of Dylan Thurston about triple crossing diagrams. We also apply our result to make progress on an instance of the generalized Baues problem. 2021-09-20T17:16:55Z 2021-09-20T17:16:55Z 2020-02-17 2020-09-24T21:11:36Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/131399 Selecta Mathematica. 2020 Feb 17;26(1):15 en https://doi.org/10.1007/s00029-020-0544-1 Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer Nature Switzerland AG application/pdf Springer International Publishing Springer International Publishing
spellingShingle Balitskiy, Alexey
Wellman, Julian
Flip cycles in plabic graphs
title Flip cycles in plabic graphs
title_full Flip cycles in plabic graphs
title_fullStr Flip cycles in plabic graphs
title_full_unstemmed Flip cycles in plabic graphs
title_short Flip cycles in plabic graphs
title_sort flip cycles in plabic graphs
url https://hdl.handle.net/1721.1/131399
work_keys_str_mv AT balitskiyalexey flipcyclesinplabicgraphs
AT wellmanjulian flipcyclesinplabicgraphs