title: Cycles and clustering in multiplex networks.
abstract: In multiplex networks, cycles cannot be characterized only by their length, as edges may occur in different layers in different combinations. We define a classification of cycles by the number of edges in each layer and the number of switches between layers. We calculate the expected number of cycles of each type in the configuration model of a large sparse multiplex network. Our method accounts for the full degree distribution including correlations between degrees in different layers. In particular, we obtain the numbers of cycles of length 3 of all possible types. Using these, we give a complete set of clustering coefficients and their expected values. We show that correlations between the degrees of a vertex in different layers strongly affect the number of cycles of a given type, and the number of switches between layers. Both increase with assortative correlations and are strongly decreased by disassortative correlations. The effect of correlations on clustering coefficients is equally pronounced.
authors.affiliation: Department of Physics & I3N, University of Aveiro, Portugal.
authors.forename: Gareth J
authors.initials: GJ
authors.lastname: Baxter
authors.affiliation: Idiro Analytics, Clarendon House, 39 Clarendon Street, Dublin 2, Ireland.|MACSI, Department of Mathematics and Statistics, University of Limerick, Ireland.
authors.forename: Davide
authors.initials: D
authors.lastname: Cellai
authors.affiliation: Department of Physics & I3N, University of Aveiro, Portugal.|A. F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Dorogovtsev
authors.affiliation: Department of Physics & I3N, University of Aveiro, Portugal.
authors.forename: José F F
authors.initials: JF
authors.lastname: Mendes