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arXiv math/0001128math.CO
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局部树宽、排除子项和近似算法

Local tree-width, excluded minors, and approximation algorithms

Martin Grohe

摘要:

图G=(V,E)的局部树宽是函数ltw^G:N -> N,它使G中的r-邻域的最大树宽与每个自然数r相关联.我们的主要图论结果是一个分解定理的排除未成年人的图,基本上说,这样的图可以分解成树的图有界的局部树宽度。作为这个定理的应用,我们证明了一些组合最优化问题,如最小顶点覆盖、最小支配集和最大独立集,当被限制在一类图中,且图中有一个排除子图时,它们具有多项式时间的近似方案.

英文摘要:

The local tree-width of a graph G=(V,E) is the function ltw^G: N -> N that associates with every natural number r the maximal tree-width of an r-neighborhood in G. Our main graph theoretic result is a decomposition theorem for graphs with excluded minors that essentially says that such graphs can be decomposed into trees of graphs of bounded local tree-width. As an application of this theorem, we show that a number of combinatorial optimization problems, such as Minimum Vertex Cover, Minimum Dominating Set, and Maximum Independent Set have a polynomial time approximation scheme when restricted to a class of graphs with an excluded minor.

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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