Arrangements of equal minors in the positive Grassmannian - Inria - Institut national de recherche en sciences et technologies du numérique Access content directly
Conference Papers Discrete Mathematics and Theoretical Computer Science Year : 2014

Arrangements of equal minors in the positive Grassmannian


We discuss arrangements of equal minors in totally positive matrices. More precisely, we would like to investigate the structure of possible equalities and inequalities between the minors. We show that arrangements of equals minors of largest value are in bijection with sorted sets, which earlier appeared in the context of alcoved polytopes and Gröbner bases. Maximal arrangements of this form correspond to simplices of the alcoved triangulation of the hypersimplex; and the number of such arrangements equals the Eulerian number. On the other hand, we conjecture and prove in many cases that arrangements of equal minors of smallest value are exactly the weakly separated sets. Weakly separated sets, originally introduced by Leclerc and Zelevinsky, are closely related to the \textitpositive Grassmannian and the associated cluster algebra.
Fichier principal
Vignette du fichier
dmAT0167.pdf (790.98 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

hal-01207569 , version 1 (01-10-2015)



Miriam Farber, Alexander Postnikov. Arrangements of equal minors in the positive Grassmannian. 26th International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2014), 2014, Chicago, United States. pp.777-788, ⟨10.46298/dmtcs.2441⟩. ⟨hal-01207569⟩


152 View
697 Download



Gmail Facebook Twitter LinkedIn More