Strong nonexponential relaxation and memory effects in a fluid with nonlinear drag
A Patrón1, B Sánchez-Rey2, A Prados1
1Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, E-41080 Sevilla, Spain.
Physical Review. E
|January 15, 2022
Summary
This study reveals that fluids with nonlinear drag exhibit complex glassy behavior at low temperatures, characterized by long-lived nonequilibrium states. This behavior is independent of nonlinearity and collision rates, persisting even in collisionless systems.
Area of Science:
- Complex systems
- Statistical physics
- Nonlinear dynamics
Background:
- Nonlinear Brownian motion and kinetic theory describe fluid dynamics.
- Understanding glassy states in driven systems is crucial.
Purpose of the Study:
- Analyze the dynamical evolution of a fluid with nonlinear drag.
- Investigate the emergence of glassy behavior and its underlying mechanisms.
Main Methods:
- Utilized the Enskog-Fokker-Planck equation for kinetic-level analysis.
- Developed an extended Sonine approximation including sixth cumulants for simulations.
Main Results:
- Observed a long-lived nonequilibrium state controlling glassy response, independent of nonlinearity and collision rates.
- Demonstrated persistence of this behavior in the collisionless limit (nonlinear Fokker-Planck equation).
- Identified nonexponential relaxation, algebraic decay, and strong memory effects with universal scaling properties.
Conclusions:
- The fluid's glassy response is robust and characterized by universal scaling laws.
- Extended Sonine approximations are necessary for accurate simulation of these kinetic phenomena.
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