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arXiv 1610.04055cs.DScs.CC
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有界度布尔计数约束满足问题的配分函数逼近

Approximating partition functions of bounded-degree Boolean counting Constraint Satisfaction Problems

Andreas Galanis, Leslie Ann Goldberg, Kuan Yang

摘要:

研究了有限度下近似计数约束满足问题的复杂性.具体地说,给定一个布尔约束语言$Γ$和一个度界$Δ$,我们研究了#CSP $_Δ(Γ)$的复杂性,即计算满足$Γ$约束且其变量最多出现$Δ$次的CSP实例的赋值问题.我们的主要结果表明:(i)如果$Γ$中的每个函数都是仿射的,则#CSP $_Δ(Γ)$对于所有$Δ$都在FP中,(ii)否则,如果$Γ$中的每个函数都在称为IM $_2$的类中,则对于所有足够大的$Δ$,#CSP $_Δ(Γ)$在近似保持(AP)约简下等价于计数问题#BIS(二分图中独立集的计数问题)(iii)否则,对于所有足够大的$Δ$,即使在指数因子内,也是NP-困难的,以近似#CSP $_Δ(Γ)$的实例的满意分配的数目。我们的结果扩展了以前的结果,只适用于所谓的“保守”的情况。

英文摘要:

We study the complexity of approximate counting Constraint Satisfaction Problems (#CSPs) in a bounded degree setting. Specifically, given a Boolean constraint language $Γ$ and a degree bound $Δ$, we study the complexity of #CSP$_Δ(Γ)$, which is the problem of counting satisfying assignments to CSP instances with constraints from $Γ$ and whose variables can appear at most $Δ$ times. Our main result shows that: (i) if every function in $Γ$ is affine, then #CSP$_Δ(Γ)$ is in FP for all $Δ$, (ii) otherwise, if every function in $Γ$ is in a class called IM$_2$, then for all sufficiently large $Δ$, #CSP$_Δ(Γ)$ is equivalent under approximation-preserving (AP) reductions to the counting problem #BIS (the problem of counting independent sets in bipartite graphs) (iii) otherwise, for all sufficiently large $Δ$, it is NP-hard to approximate the number of satisfying assignments of an instance of #CSP$_Δ(Γ)$, even within an exponential factor. Our result extends previous results, which apply only in the so-called "conservative" case.

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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