title: Ranking in interconnected multilayer networks reveals versatile nodes.
abstract: The determination of the most central agents in complex networks is important because they are responsible for a faster propagation of information, epidemics, failures and congestion, among others. A challenging problem is to identify them in networked systems characterized by different types of interactions, forming interconnected multilayer networks. Here we describe a mathematical framework that allows us to calculate centrality in such networks and rank nodes accordingly, finding the ones that play the most central roles in the cohesion of the whole structure, bridging together different types of relations. These nodes are the most versatile in the multilayer network. We investigate empirical interconnected multilayer networks and show that the approaches based on aggregating--or neglecting--the multilayer structure lead to a wrong identification of the most versatile nodes, overestimating the importance of more marginal agents and demonstrating the power of versatility in predicting their role in diffusive and congestion processes.
authors.affiliation: Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors.forename: Manlio
authors.initials: M
authors.lastname: De Domenico
authors.affiliation: Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Solé-Ribalta
authors.affiliation: 1] Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain [2] LaTTiCe-CNRS, École Normale Supérieure, 75005 Paris, France [3] Institut des Systèmes Complexes - Paris Île-de-France (ISC-PIF), 75013 Paris, France.
authors.forename: Elisa
authors.initials: E
authors.lastname: Omodei
authors.affiliation: Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors.forename: Sergio
authors.identifier: 0000000318200062
authors.initials: S
authors.lastname: Gómez
authors.affiliation: 1] Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona, Spain [2] IPHES, Institut Català de Paleoecologia Humana i Evolució Social, 43007 Tarragona, Spain.
authors.forename: Alex
authors.identifier: 0000000309370334
authors.initials: A
authors.lastname: Arenas