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arXiv · 1804.07431

Finding Cliques in Social Networks: A New Distribution-Free Model

Jacob Fox·Tim Roughgarden·C. Seshadhri·Fan Wei·Nicole Wein
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Abstract

We propose a new distribution-free model of social networks. Our definitions are motivated by one of the most universal signatures of social networks, triadic closure---the property that pairs of vertices with common neighbors tend to be adjacent. Our most basic definition is that of a "$c$-closed" graph, where for every pair of vertices $u,v$ with at least $c$ common neighbors, $u$ and $v$ are adjacent. We study the classic problem of enumerating all maximal cliques, an important task in social network analysis. We prove that this problem is fixed-parameter tractable with respect to $c$ on $c$-closed graphs. Our results carry over to "weakly $c$-closed graphs", which only require a vertex deletion ordering that avoids pairs of non-adjacent vertices with $c$ common neighbors. Numerical experiments show that well-studied social networks tend to be weakly $c$-closed for modest values of $c$.

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BibTeXRIS

Jacob Fox, Tim Roughgarden, C. Seshadhri, Fan Wei, Nicole Wein. 2018-04-20. Finding Cliques in Social Networks: A New Distribution-Free Model. https://arxiv.org/abs/1804.07431

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