A mean-field approach to multiple, long-delayed systems

The concept of multiple, long-delayed feedback systems is introduced and discussed with reference to a paradigmatic model. We analyze how the resulting chaotic dynamics is affected by the delay distribution. Via a mean-field approach, we show that a spatiotemporal representation equivalent to the one developed for the single delay can be extended to this wider class of dynamical systems. Numerical simulations are complemented by a theoretical study based on a multiple-scale analysis, which, in the vicinity of a Hopf bifurcation, allows mapping the initial model onto a complex Ginzburg Landau equation. As a result, we find that the only relevant feature influenced by the multiple delays is the size of the coherent spatiotemporal structures which, in turn, depends exclusively on a generalized variance of the delay distribution.