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Thermodynamics of Superdiffusion Generated by Lévy-Wiener Fluctuating Forces
Łukasz Kuśmierz1, Bartłomiej Dybiec2, Ewa Gudowska-Nowak2
1Laboratory for Neural Computation and Adaptation, RIKEN Center for Brain Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Entropy (Basel, Switzerland)
|December 3, 2020
Summary
Scale-free Lévy motion, a generalized Wiener process, models non-Gaussian noise in stochastic differential equations. This study shows such systems violate detailed balance, leading to non-Gibbsian stationary states.
Area of Science:
- Statistical Physics
- Stochastic Processes
- Non-linear Dynamics
Background:
- Scale-free Lévy motion generalizes Wiener processes, modeling natural signals via overdamped Langevin equations.
- These processes are crucial for understanding non-Gaussian noise in complex systems.
- The stationary state of such systems is typically determined by system parameters.
Purpose of the Study:
- To analyze the dynamics of a Brownian-like particle driven by external forces and uncorrelated Lévy fluctuations.
- To investigate the detailed balance condition in Markov processes with stability index α < 2.
- To explore the consequences of non-Gibbsian stationary states on fluctuation-dissipation theorems.
Main Methods:
- Modeling particle dynamics using an overdamped Langevin stochastic differential equation with Lévy noise.
- Analysis of the Markov process properties, including stationary probability density and current.
- Derivation of the fluctuation-dissipation theorem under weak external forcing.
Main Results:
- The analyzed Markov process with stability index α < 2 violates detailed balance.
- A non-vanishing current exists in the stationary state, indicating a non-equilibrium condition.
- The non-Gibbsian nature of the stationary state impacts the fluctuation-dissipation theorem.
Conclusions:
- Systems driven by scale-free Lévy motion can exhibit non-equilibrium stationary states.
- Violation of detailed balance is a key characteristic of these non-Gibbsian states.
- Understanding these states is crucial for accurately describing complex physical phenomena and deriving generalized physical laws.
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