arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0911.4732cs.DMcs.DS
收藏

二部图的独立集的图多项式

A graph polynomial for independent sets of bipartite graphs

Qi Ge, Daniel Stefankovic

摘要:

我们引入了一个新的图多项式,编码有趣的性质的图,例如,匹配的数量和完美匹配的数量。最重要的是,对于二分图,多项式编码独立集的数量(#BIS)。我们分析了多项式在有理点上精确求值的复杂性,并证明了对于大多数点,精确求值是P-困难的(假设广义黎曼假设),而对于其余的点,精确求值是平凡的。我们猜想,一个自然的马尔可夫链可以用来近似估计的多项式的参数范围。该猜想,如果真的,将意味着一个近似计数算法的#BIS,一个问题显示,由[Dyer et al. 2004],是完整的(相对于,所谓的,AP-减少)为一个丰富的逻辑定义的子类的#P。我们给我们的猜想一个温和的支持,证明马尔可夫链是快速混合的树。作为一个副产品,我们表明,“单键翻转”随机簇模型的马尔可夫链是迅速混合恒定树宽图。

英文摘要:

We introduce a new graph polynomial that encodes interesting properties of graphs, for example, the number of matchings and the number of perfect matchings. Most importantly, for bipartite graphs the polynomial encodes the number of independent sets (#BIS). We analyze the complexity of exact evaluation of the polynomial at rational points and show that for most points exact evaluation is #P-hard (assuming the generalized Riemann hypothesis) and for the rest of the points exact evaluation is trivial. We conjecture that a natural Markov chain can be used to approximately evaluate the polynomial for a range of parameters. The conjecture, if true, would imply an approximate counting algorithm for #BIS, a problem shown, by [Dyer et al. 2004], to be complete (with respect to, so called, AP-reductions) for a rich logically defined sub-class of #P. We give a mild support for our conjecture by proving that the Markov chain is rapidly mixing on trees. As a by-product we show that the "single bond flip" Markov chain for the random cluster model is rapidly mixing on constant tree-width graphs.

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。

↑