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arXiv · 2109.01361

Lyapunov spectrum scaling for classical many-body dynamics close to integrability

Merab Malishava·Sergej Flach
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Abstract

We propose a novel framework to characterize the thermalization of many-body dynamical systems close to integrable limits using the scaling properties of the full Lyapunov spectrum. We use a classical unitary map model to investigate macroscopic weakly nonintegrable dynamics beyond the limits set by the KAM regime. We perform our analysis in two fundamentally distinct long-range and short-range integrable limits which stem from the type of nonintegrable perturbations. Long-range limits result in a single parameter scaling of the Lyapunov spectrum, with the inverse largest Lyapunov exponent being the only diverging control parameter and the rescaled spectrum approaching an analytical function. Short-range limits result in a dramatic slowing down of thermalization which manifests through the rescaled Lyapunov spectrum approaching a non-analytic function. An additional diverging length scale controls the exponential suppression of all Lyapunov exponents relative to the largest one.

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Merab Malishava, Sergej Flach. 2021-09-03. Lyapunov spectrum scaling for classical many-body dynamics close to integrability. https://doi.org/10.1103/physrevlett.128.134102

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