arXiv subjects

Diego Pazó

Publications and source records attributed to Diego Pazó.

39 records · Page 3Linked to original sources

arXiv2007

Spatiotemporal structure of Lyapunov vectors in chaotic coupled-map lattices

The spatiotemporal dynamics of Lyapunov vectors (LVs) in spatially extended chaotic systems is studied by means of coupled-map lattices. We determine intrinsic length scales and spatiotemporal correlations of LVs corresponding to the leading unstable directions by translating the problem to the language of scale-invariant growing surfaces. We find that the so-called 'characteristic' LVs exhibit spatial localization, strong clustering around given spatiotemporal loci, and remarkable dynamic scaling properties of the corresponding surfaces. In contrast, the commonly used backward LVs (obtained through Gram-Schmidt orthogonalization) spread all over the system and do not exhibit dynamic scaling due to artifacts in the dynamical correlations by construction.

nlin.CD↗

arXiv2006

Universal behavior in populations composed of excitable and self-oscillatory elements

We study the robustness of self-sustained oscillatory activity in a globally coupled ensemble of excitable and oscillatory units. The critical balance to achieve collective self-sustained oscillations is analytically established. We also report a universal scaling function for the ensemble's mean frequency. Our results extend the framework of the `Aging Transition' [Phys. Rev. Lett. 93, 104101 (2004)] including a broad class of dynamical systems potentially relevant in biology.

nlin.AO↗

arXiv2002

Travelling fronts in an array of coupled symmetric bistable units

A symmetry breaking mechanism is shown to occur in an array composed of symmetric bistable Lorenz units coupled through a nearest neighbour scheme. When the coupling is increased, we observe the route: standing --> oscillating --> travelling front. In some circumstances, this route can be described in terms of a gluing of two cycles on the plane. In this case, the asymptotic behaviour of the velocity of the front is found straightforward. However, it may also happen that the gluing bifurcation involves a saddle-focus fixed point. If so, front dynamics may become quite complex displaying several oscillating and propagating regimes, including chaotic (Shil'nikov-type) front propagation. Finally, we compare our results with different couplings and with other discrete bistable media.

nlin.PS↗