Berlin 2015 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 56: Aging in Physical and Biological Systems (focus session, joint DY/BP)

BP 56.5: Vortrag

Freitag, 20. März 2015, 11:30–11:45, BH-N 334

Aging of Classical Oscillators during a Noise-Driven Migration of Oscillator Phases — •Hildegard Meyer-Ortmanns and Florin Ionita — Jacobs University Bremen, 28759 Bremen

We consider classical nonlinear oscillators like rotators and Kuramoto oscillators on hexagonal lattices of small or intermediate size. When the coupling between the elements is repulsive and the bonds are frustrated, we observe coexisting states, each one with its own basin of attraction. For special lattices sizes the multiplicity of stationary states gets extremely rich. When disorder is introduced into the system by additive or multiplicative Gaussian noise, we observe a noise-driven migration of oscillator phases in a rather rough potential landscape. Upon this migration, a multitude of different escape times from one metastable state to the next is generated. Based on these observations, it does not come as a surprise that the set of oscillators shows physical aging. Physical aging is characterized by nonexponential relaxation after a perturbation, breaking of time-translation invariance, and dynamical scaling. When our system of oscillators is quenched from the regime of a unique fixed point toward the regime of multistable limit-cycle solutions, the autocorrelation functions depend on the waiting time after the quench, so that time translation invariance is broken, and dynamical scaling is observed for a certain range of time scales. It is an open question as to whether physical aging as we have studied here, is also responsible for biological aging in these excitable or oscillatory systems in biological realizations.

F. Ionita, H. Meyer-Ortmanns, Phys. Rev. Lett. 112, 094101 (2014).