The hypergraph unreliability problem asks for the probability that a hypergraph gets disconnected when every hyperedge fails independently with a given probability. For graphs, the unreliability problem has been studied over many decades, and multiple fully polynomial-time approximation schemes are known starting with the work of Karger (STOC 1995). In contrast, prior to this work, no non-trivial result was known for hypergraphs (of arbitrary rank). In this paper, we give quasi-polynomial time approximation schemes for the hypergraph unreliability problem. For any fixed $\varepsilon \in (0, 1)$, we first give a $(1+\varepsilon)$-approximation algorithm that runs in $m^{O(\log n)}$ time on an $m$-hyperedge, $n$-vertex hypergraph. Then, we improve the running time to $m\cdot n^{O(\log^2 n)}$ with an additional exponentially small additive term in the approximation.
翻译:超图不可靠性问题要求计算当每条超边以给定概率独立失效时,超图失去连通的概率。对于图而言,不可靠性问题已历经数十年的研究,自Karger(STOC 1995)的开创性工作以来,已提出多种完全多项式时间近似方案。然而,在此工作之前,针对(任意秩的)超图尚无任何非平凡结果。本文给出了超图不可靠性问题的拟多项式时间近似方案。对于任意固定的$\varepsilon \in (0, 1)$,我们首先提出一个$(1+\varepsilon)$-近似算法,该算法在$m$条超边、$n$个顶点的超图上运行时间为$m^{O(\log n)}$。随后,我们将运行时间改进至$m\cdot n^{O(\log^2 n)}$,并在近似中增加一个指数级小的加性项。