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arXiv 1408.6573math.CO
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具有非奇异$N_2$的三重三元系

Threefold triple systems with nonsingular $N_2$

Peter J. Dukes, Kseniya Garaschuk

摘要:

关于图和超图的关联矩阵的秩与它们的组合结构之间的关系,已有许多结果。在这里,我们考虑广义关联矩阵$N_2$(定义为包含对的边缘)的一类自然超图:三元系与索引为3。这样的系统与非奇异$N_2$(在有理数)似乎是相当罕见的,但他们可以与PBD封闭构造。事实上,对于大的阶数$v$,获得了接近$\binom{v}{2}$的秩的范围。

英文摘要:

There are various results connecting ranks of incidence matrices of graphs and hypergraphs with their combinatorial structure. Here, we consider the generalized incidence matrix $N_2$ (defined by inclusion of pairs in edges) for one natural class of hypergraphs: the triple systems with index three. Such systems with nonsingular $N_2$ (over the rationals) appear to be quite rare, yet they can be constructed with PBD closure. In fact, a range of ranks near $\binom{v}{2}$ is obtained for large orders $v$.

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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