摘要翻译:
固定热带射影空间Tp^{d-1}中n个热带共线点的空间T_{d,n}等价于秩至多为2的矩阵的行列式簇的热带化,该矩阵由实d×n个热带或Kapranov秩至多为2的矩阵组成,列的模射影等价。我们证明了它等于tp^{d-1}中n个有标记热带线的模空间M_{0,n}(tp^{d-1},1)在求值图下的象。因此,我们利用M_{0,n}(Tp^{d-1},1)的单纯扇结构,导出了T_{d,n}的自然单纯扇结构,它与d+n分类群的系统树空间的单纯扇结构一致。Trappmann和Ziegler证明了系统树的空间是可壳的。利用类似的方法,我们证明了T_{d,n}在我们的单纯扇结构下是可壳的,并计算了原点链接的同调性。T_{d,n}的脱壳性是Develin在2005年提出的。
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英文标题:
《The space of tropically collinear points is shellable》
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作者:
Hannah Markwig, Josephine Yu
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最新提交年份:
2009
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分类信息:
一级分类:Mathematics 数学
二级分类:Combinatorics 组合学
分类描述:Discrete mathematics, graph theory, enumeration, combinatorial optimization, Ramsey theory, combinatorial game theory
离散数学,图论,计数,组合优化,拉姆齐理论,组合对策论
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一级分类:Mathematics 数学
二级分类:Algebraic Geometry 代数几何
分类描述:Algebraic varieties, stacks, sheaves, schemes, moduli spaces, complex geometry, quantum cohomology
代数簇,叠,束,格式,模空间,复几何,量子上同调
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英文摘要:
The space T_{d,n} of n tropically collinear points in a fixed tropical projective space TP^{d-1} is equivalent to the tropicalization of the determinantal variety of matrices of rank at most 2, which consists of real d x n matrices of tropical or Kapranov rank at most 2, modulo projective equivalence of columns. We show that it is equal to the image of the moduli space M_{0,n}(TP^{d-1},1) of n-marked tropical lines in TP^{d-1} under the evaluation map. Thus we derive a natural simplicial fan structure for T_{d,n} using a simplicial fan structure of M_{0,n}(TP^{d-1},1) which coincides with that of the space of phylogenetic trees on d+n taxa. The space of phylogenetic trees has been shown to be shellable by Trappmann and Ziegler. Using a similar method, we show that T_{d,n} is shellable with our simplicial fan structure and compute the homology of the link of the origin. The shellability of T_{d,n} has been conjectured by Develin in 2005.
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PDF链接:
https://arxiv.org/pdf/0711.0944