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arXiv 0907.2053math.AGmath.CO
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星树度量的热带混合

Tropical mixtures of star tree metrics

Maria Angelica Cueto

摘要:

我们研究树度量,可以实现为两个星树度量的混合物。我们证明了,只有树承认这样的分解是那些来自一棵树,最多有一个内部的边缘,其重量满足一定的线性不等式。我们还刻画了相应的混合映射的纤维。此外,我们讨论了热带割线品种的一般框架,我们解释我们的结果在此设置。最后,我们证明了$n$分类群上的树度量秩集是无界的。

英文摘要:

We study tree metrics that can be realized as a mixture of two star tree metrics. We prove that the only trees admitting such a decomposition are the ones coming from a tree with at most one internal edge, and whose weight satisfies certain linear inequalities. We also characterize the fibers of the corresponding mixture map. In addition, we discuss the general framework of tropical secant varieties and we interpret our results within this setting. Finally, we show that the set of tree metric ranks of metrics on $n$ taxa is unbounded.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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