eprintid: 2685
rev_number: 8
eprint_status: archive
userid: 69
dir: disk0/00/00/26/85
datestamp: 2015-05-19 10:38:31
lastmod: 2015-05-19 10:38:31
status_changed: 2015-05-19 10:38:31
type: monograph
metadata_visibility: no_search
creators_name: Borassi, Michele
creators_name: Chessa, Alessandro
creators_name: Caldarelli, Guido
creators_id: 
creators_id: alessandro.chessa@imtlucca.it
creators_id: guido.caldarelli@imtlucca.it
title: Hyperbolicity Measures "Democracy" in Real-World Networks
ispublished: submitted
subjects: HA
subjects: HM
subjects: QC
divisions: EIC
full_text_status: none
monograph_type: working_paper
abstract: We analyze the hyperbolicity of real-world networks, a geometric quantity that measures if a space is negatively curved. In our interpretation, a network with small hyperbolicity is "aristocratic", because it contains a small set of vertices involved in many shortest paths, so that few elements "connect" the systems, while a network with large hyperbolicity has a more "democratic" structure with a larger number of crucial elements.
We prove mathematically the soundness of this interpretation, and we derive its consequences by analyzing a large dataset of real-world networks. We confirm and improve previous results on hyperbolicity, and we analyze them in the light of our interpretation.
Moreover, we study (for the first time in our knowledge) the hyperbolicity of the neighborhood of a given vertex. This allows to define an "influence area" for the vertices in the graph. We show that the influence area of the highest degree vertex is small in what we define "local" networks, like most social or peer-to-peer networks. On the other hand, if the network is built in order to reach a "global" goal, as in metabolic networks or autonomous system networks, the influence area is much larger, and it can contain up to half the vertices in the graph. In conclusion, our newly introduced approach allows to distinguish the topology and the structure of various complex networks.
date: 2015-03
date_type: submitted
publisher: ArXiv
pages: 10
institution: IMT Institute for Advanced Studies Lucca
official_url: http://arxiv.org/abs/1503.03061
citation:   Borassi, Michele and Chessa, Alessandro and Caldarelli, Guido  Hyperbolicity Measures "Democracy" in Real-World Networks.  Working Paper   ArXiv       (Submitted)