Flag arrangements and triangulations of products of simplices

dc.creatorArdila, Federico
dc.creatorBilley, Sara
dc.date2006-05-22
dc.date.accessioned2026-07-07T07:14:27Z
dc.date.available2026-07-07T07:14:27Z
dc.descriptionWe investigate the line arrangement that results from intersecting d complete flags in C^n. We give a combinatorial description of the matroid T_{n,d} that keeps track of the linear dependence relations among these lines. We prove that the bases of the matroid T_{n,3} characterize the triangles with holes which can be tiled with unit rhombi. More generally, we provide evidence for a conjectural connection between the matroid T_{n,d}, the triangulations of the product of simplices Delta_{n-1} x Δ_{d-1}, and the arrangements of d tropical hyperplanes in tropical (n-1)-space. Our work provides a simple and effective criterion to ensure the vanishing of many Schubert structure constants in the flag manifold, and a new perspective on Billey and Vakil's method for computing the non-vanishing ones.
dc.description39 pages, 12 figures, best viewed in color
dc.identifierhttps://arxiv.org/abs/math/0605598
dc.identifierhttp://arxiv.org/abs/math/0605598
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/112883
dc.subjectCombinatorics
dc.subjectAlgebraic Geometry
dc.subject52C35; 05B35; 14M15; 52C22; 52C20
dc.titleFlag arrangements and triangulations of products of simplices
dc.typetext

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