论文标题

关于图的距离矩阵的等级

On the rank of the distance matrix of graphs

论文作者

Dratman, Ezequiel, Grippo, Luciano N., Moyano, Verónica, Pastine, Adrián

论文摘要

令$ g $为$ v(g)= \ {v_1,\ ldots,v_n \} $的连接图。 $(i,j)$ - $ g $的距离矩阵$ d(g)的条目是$ v_i $和$ v_j $之间的距离。在本文中,使用著名的Ramsey定理,我们证明,对于每个整数$ k \ ge 2 $,都有有限数量的图表,其距离矩阵具有等级$ k $。我们展示的图表列表,距离为$ 2 $和$ 3 $的距离矩阵。此外,我们研究属于图形家族的图形距离矩阵的等级,其直径最多是两个图形,即琐碎的完美图。我们证明,对于每个$η\ ge 1 $,都有一个毫无疑问的图形,带有无效$η$。我们还表明,对于阈值图,这是琐碎的完美图家族的子家族,无效的是一个。

Let $G$ be a connected graph with $V(G)=\{v_1,\ldots,v_n\}$. The $(i,j)$-entry of the distance matrix $D(G)$ of $G$ is the distance between $v_i$ and $v_j$. In this article, using the well-known Ramsey's theorem, we prove that for each integer $k\ge 2$, there is a finite amount of graphs whose distance matrices have rank $k$. We exhibit the list of graphs with distance matrices of rank $2$ and $3$. Besides, we study the rank of the distance matrices of graphs belonging to a family of graphs with their diameters at most two, the trivially perfect graphs. We show that for each $η\ge 1$ there exists a trivially perfect graph with nullity $η$. We also show that for threshold graphs, which are a subfamily of the family of trivially perfect graphs, the nullity is bounded by one.

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