title: Opinion formation models on a gradient.
abstract: Statistical physicists have become interested in models of collective social behavior such as opinion formation, where individuals change their inherently preferred opinion if their friends disagree. Real preferences often depend on regional cultural differences, which we model here as a spatial gradient g in the initial opinion. The gradient does not only add reality to the model. It can also reveal that opinion clusters in two dimensions are typically in the standard (i.e., independent) percolation universality class, thus settling a recent controversy about a non-consensus model. However, using analytical and numerical tools, we also present a model where the width of the transition between opinions scales proportional g(-1/4), not proportional g(-4/7) as in independent percolation, and the cluster size distribution is consistent with first-order percolation.
authors.affiliation: Institute of Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Department of Engineering Mathematics, University of Bristol, Bristol, United Kingdom; Department of Mathematics, Imperial College London, London, United Kingdom.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Gastner
authors.affiliation: Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom.
authors.forename: Nikolitsa
authors.initials: N
authors.lastname: Markou
authors.affiliation: Department of Mathematics, Imperial College London, London, United Kingdom.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Pruessner
authors.affiliation: Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom.
authors.forename: Moez
authors.initials: M
authors.lastname: Draief
mesh_terms: D016000:Cluster Analysis; D008962:Models, Theoretical; D012919:Social Behavior