Higher Secondary Polytopes for Two-Dimensional Zonotopes
| Autor: | Bullock, Elisabeth, Gravel, Katie |
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| Rok vydání: | 2020 |
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| Druh dokumentu: | Working Paper |
| Popis: | Very recently, Galashin, Postnikov, and Williams introduced the notion of higher secondary polytopes, generalizing the secondary polytope of Gelfand, Kapranov, and Zelevinsky. Given an $n$-point configuration $\mathcal{A}$ in $\mathbb{R}^{d-1}$, they define a family of convex $(n-d)$-dimensional polytopes $\widehat{\Sigma}_{1}, \ldots, \widehat{\Sigma}_{n-d}$. The $1$-skeletons of this family of polytopes are the flip graphs of certain combinatorial configurations which generalize triangulations of $\text{conv} \mathcal{A}$. We restrict our attention to $d=2$. First, we relate the $1$-skeleton of the Minkowski sum $\widehat{\Sigma}_{k} + \widehat{\Sigma}_{k-1}$ to the flip graph of "hypertriangulations" of the deleted $k$-sum of $\mathcal{A}$ when $\mathcal{A}$ consists of distinct points. Second, we compute the diameter of $\widehat{\Sigma}_{k}$ and $\widehat{\Sigma}_{k}+\widehat{\Sigma}_{k-1}$ for all $k$. Comment: 20 pages, 11 figures |
| Databáze: | arXiv |
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