A Fusion Link Prediction Method Based on Limit

The theoretical limit of link prediction is a fundamental problem in this field. Taking the 7 network structure as object to research this problem is the mainstream method. This paper 8 proposes a new viewpoint that link prediction methods can be divided into single or combination 9 methods, based on the way they derive the similarity matrix, and investigates whether there a 10 theoretical limit exists for combination methods. We propose and prove necessary and sufficient 11 conditions for the combination method to reach the theoretical limit. The limit theorem reveals the 12 essence of combination method that is to estimate probability density functions of existing links 13 and nonexistent links. Based on limit theorem, a new combination method, theoretical limit fusion 14 (TLF) method, is proposed. Simulations and experiments on real networks demonstrated that TLF 15 method can achieve higher prediction accuracy. 16