String cone and superpotential combinatorics for flag and Schubert varieties in type A
String cone and superpotential combinatorics for flag and Schubert varieties in type A
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A 型旗形和舒伯特变种的弦锥和超势组合学
DOI:
10.1016/j.jcta.2019.04.006
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发表时间:
2016
期刊:
影响因子:
--
通讯作者:
G. Fourier
中科院分区:
文献类型:
--
作者:
L. Bossinger;G. Fourier
We study the combinatorics of pseudoline arrangements and their relation to the geometry of flag and Schubert varieties. We associate to each pseudoline arrangement two polyhedral cones, defined in a dual manner. We prove that one of them is the weighted string cone by Littelmann and Berenstein-Zelevinsky. For the other we show how it arises in the framework of cluster varieties and mirror symmetry by Gross-Hacking-Keel-Kontsevich: for the flag variety the cone is the tropicalization of their superpotential while for Schubert varieties a restriction of the superpotential is necessary.We prove that the two cones are unimodularly equivalent. As a corollary of our combinatorial result we realize Caldero's toric degenerations of Schubert varieties as GHKK-degeneration using cluster theory.