Mass media and repulsive interactions in continuous-opinion dynamics
5 pages, 6 figures. ; This letter focus on the effect of repulsive interactions on the adoption of an external message in an opinion model. With a simple change in the rules, we modify the Deffuant \emph{et al.} model to incorporate the presence of repulsive interactions. We will show that information receptiveness is optimal for an intermediate fraction of repulsive links. Using the master equation as well as Monte Carlo simulations of the message-free model, we identify the point where the system becomes optimally permeable to external influence with an order-disorder transition. ; We acknowledge financial support by the MEC (Spain) and FEDER (EU) through project FIS2007-60327. TVM acknowledges the support of FCT (Portugal) through Grant No. SFRH/BD/23709/2005, MP is supported by the Belgian Federal Government (IAP project "NOSY: Nonlinear systems, stochastic processes and statistical mechanics"). ; Peer reviewed