Collective stochastic coherence and synchronizability in weighted scale-free networks

摘要

Coupling frequently enhances noise-induced coherence and synchronization ininteracting nonlinear systems, but it does so separately. In principlecollective stochastic coherence and synchronizability are incompatiblephenomena, since strongly synchronized elements behave identically and thustheir response to noise is indistinguishable to that of a single element.Therefore one can expect systems that synchronize well to have a poorcollective response to noise. Here we show that, in spite of this apparentconflict, a certain coupling architecture is able to reconcile the twoproperties. Specifically, our results reveal that weighted scale-free networksof diffusively coupled excitable elements exhibit both high synchronizabilityof their subthreshold dynamics and a good collective response to noise of theirpulsed dynamics. This is established by comparing the behavior of this systemto that of random, regular, and unweighted scale-free networks. We attributethe optimal response of weighted scale-free networks to the link homogeneity(with respect to node degree) provided by the weighting procedure, whichbalances the degree heterogeneity typical of SFNs.