Statistics Papers

Document Type

Journal Article

Date of this Version

2015

Publication Source

The Annals of Applied Probability

Volume

25

Issue

5

Start Page

2462

Last Page

2502

DOI

10.1214/14-AAP1053

Abstract

Condensation phenomenon is often observed in social networks such as Twitter where one “superstar” vertex gains a positive fraction of the edges, while the remaining empirical degree distribution still exhibits a power law tail. We formulate a mathematically tractable model for this phenomenon that provides a better fit to empirical data than the standard preferential attachment model across an array of networks observed in Twitter. Using embeddings in an equivalent continuous time version of the process, and adapting techniques from the stable age-distribution theory of branching processes, we prove limit results for the proportion of edges that condense around the superstar, the degree distribution of the remaining vertices, maximal nonsuperstar degree asymptotics and height of these random trees in the large network limit.

Copyright/Permission Statement

The original and published work is available at: https://projecteuclid.org/euclid.aoap/1438261046#abstract

Keywords

Dynamic networks, preferential attachment, continuous time branching processes, characteristics of branching processes, multitype branching processes, Twitter, social networks, retweet graph

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Date Posted: 27 November 2017

This document has been peer reviewed.