Positroids and Schubert matroids
Positroids and Schubert matroids
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正拟阵和舒伯特拟阵
DOI：
10.1016/j.jcta.2011.06.006
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Suho Oh
中科院分区：
文献类型：
--
作者：
Suho Oh
波斯特尼科夫以完全非负的格拉斯曼函数对细胞进行了组合描述。这些细胞对应于一类特殊的类阵，称为正类阵。我们证明了他的猜想：正似体正是循环移位的舒伯特拟阵的交集。这导致了易于计算的正类的组合描述。
Postnikov gave a combinatorial description of the cells in a totally nonnegative Grassmannian. These cells correspond to a special class of matroids called positroids. We prove his conjecture that a positroid is exactly an intersection of cyclically shifted Schubert matroids. This leads to a combinatorial description of positroids that is easily computable.