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arXiv math/0505155math.CO
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连通图的一种划分

A partition of connected graphs

Gus Wiseman

摘要:

我们定义了一个算法k,它取一个全序顶点集上的连通图G,并返回一棵增树R(它不一定是G的子树)。我们刻画了图的集合G,使得k(G)=R.因为这个集合具有简单的结构(它同构于非空幂集的乘积),所以很容易根据增树来评估某些图不变量。特别地,我们证明了,直到符号,系数x^q的色多项式的G是增加森林的数量与q个组件,满足一个条件,我们称之为G-连通。我们还找到了G的增G-连通树与无断圈子树之间的一个双射。

英文摘要:

We define an algorithm k which takes a connected graph G on a totally ordered vertex set and returns an increasing tree R (which is not necessarily a subtree of G). We characterize the set of graphs G such that k(G)=R. Because this set has a simple structure (it is isomorphic to a product of non-empty power sets), it is easy to evaluate certain graph invariants in terms of increasing trees. In particular, we prove that, up to sign, the coefficient of x^q in the chromatic polynomial of G is the number of increasing forests with q components that satisfy a condition that we call G-connectedness. We also find a bijection between increasing G-connected trees and broken circuit free subtrees of G.

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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