Link prediction in networks using effective transitions

Abstract We introduce a new method for predicting the formation or the detection of unobserved links in real-world networks, which we refer to as the method of effective transitions. This method relies on the theory of isospectral matrix reductions to compute the probability of eventually transitioning from one vertex to another in a (biased) random walk on the network. This link prediction technique is quite versatile and can be used to predict links in networks that are directed or undirected and are either weighted or unweighted. We apply this method to a large number of social, technological, and natural networks and show that it is competitive with other link predictors, often outperforming them. We also provide a method of approximating our effective transition method and show that aside from having much lower temporal complexity, this approximation often provides more accurate predictions than the original effective transition method. We also prove a number of results regarding our effective transition algorithm and its approximation.