title: Introduction: optimization in networks.
abstract: The recent surge in the network modeling of complex systems has set the stage for a new era in the study of fundamental and applied aspects of optimization in collective behavior. This Focus Issue presents an extended view of the state of the art in this field and includes articles from a large variety of domains in which optimization manifests itself, including physical, biological, social, and technological networked systems.
authors.affiliation: Department of Physics and Astronomy and Northwestern Institute on Complex Systems, Northwestern University, Evanston, Illinois 60208, USA. toro@nd.edu
authors.forename: Adilson E
authors.initials: AE
authors.lastname: Motter
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Toroczkai