Raúl Toral

Spain Institute for Cross-Disciplinary Physics and Complex Systems in Palma de Mallorca

Raul Toral homepage


Constructive effects induced by heterogeneity: an application to a model for opinion formation


Heterogeneity amongst the members of a society or group is usually interpreted to be a source of disorder, and this effect has to overcome by a coupling of sufficiently large magnitude if a collective behavior is to emerge from the ensemble. For example, the rhythmic applause in a concert occurs despite the intrinsic tendency of each individual to clap at a different pace than the others. A similar example is that of fireflies that manage to flash in perfect synchrony despite the unavoidable diversity in the individuals. In this talk, I will present conclusive evidence showing that different sources of heterogeneity can induce, paradoxically, a resonant collective behavior in an ensemble of coupled bistable or excitable model systems. An application will be shown in the field of opinion spreading, where a simple majority-rule model is able to follow optimally an external stimulus (advertising) under the presence of the right amount of heterogeneity amongst the constituents.

  • Date/Time: Wedensday, 19 September 2007, 11:30 - 12:30 h
  • Place: ETH Zurich, D-MTEC, Kreuzplatz 5, room F 39