{ "id": "0908.3436", "version": "v1", "published": "2009-08-24T15:21:52.000Z", "updated": "2009-08-24T15:21:52.000Z", "title": "Rank-based attachment leads to power law graphs", "authors": [ "Jeannette Janssen", "Pawel Pralat" ], "journal": "SIAM Journal of Discrete Math 24, 2010, pp. 420--440", "categories": [ "math.CO", "math.PR" ], "abstract": "We investigate the degree distribution resulting from graph generation models based on rank-based attachment. In rank-based attachment, all vertices are ranked according to a ranking scheme. The link probability of a given vertex is proportional to its rank raised to the power -a, for some a in (0,1). Through a rigorous analysis, we show that rank-based attachment models lead to graphs with a power law degree distribution with exponent 1+1/a whenever vertices are ranked according to their degree, their age, or a randomly chosen fitness value. We also investigate the case where the ranking is based on the initial rank of each vertex; the rank of existing vertices only changes to accommodate the new vertex. Here, we obtain a sharp threshold for power law behaviour. Only if initial ranks are biased towards lower ranks, or chosen uniformly at random, we obtain a power law degree distribution with exponent 1+1/a. This indicates that the power law degree distribution often observed in nature can be explained by a rank-based attachment scheme, based on a ranking scheme that can be derived from a number of different factors; the exponent of the power law can be seen as a measure of the strength of the attachment.", "revisions": [ { "version": "v1", "updated": "2009-08-24T15:21:52.000Z" } ], "analyses": { "subjects": [ "05C80", "05C07" ], "keywords": [ "rank-based attachment", "power law graphs", "power law degree distribution", "initial rank", "graph generation models" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0908.3436J" } } }