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Dynamic Approach to the Thermodynamics of Superdiffusion
This article discusses dynamic approach to the thermodynamics of superdiffusion.
Ergodicity breaking and localization
This article studies the joint action of the non-Poisson renewal events (NPR) yielding Continuous-time random walk (CTRW) with index α < 1 and two different generators of Hurst coefficient H ≠ 0.5, one generating fractional Brownian motion (FBM) and another scaled Brownian motion (SBM).
Noise-induced transition from anomalous to ordinary diffusion: The crossover time as a function of noise intensity
This article discusses noise-induced transition from anomalous to ordinary diffusion and the crossover time as a function of noise intensity.
The Markov approximation revisited: inconsistency of the standard quantum Brownian motion model
Article discussing the Markov approximation and inconsistency of the standard quantum Brownian motion model.
Deterministic Brownian Motion
The goal of this thesis is to contribute to the ambitious program of the foundation of developing statistical physics using chaos. We build a deterministic model of Brownian motion and provide a microscpoic derivation of the Fokker-Planck equation. Since the Brownian motion of a particle is the result of the competing processes of diffusion and dissipation, we create a model where both diffusion and dissipation originate from the same deterministic mechanism - the deterministic interaction of that particle with its environment. We show that standard diffusion which is the basis of the Fokker-Planck equation rests on the Central Limit Theorem, and, consequently, on the possibility of deriving it from a deterministic process with a quickly decaying correlation function. The sensitive dependence on initial conditions, one of the defining properties of chaos insures this rapid decay. We carefully address the problem of deriving dissipation from the interaction of a particle with a fully deterministic nonlinear bath, that we term the booster. We show that the solution of this problem essentially rests on the linear response of a booster to an external perturbation. This raises a long-standing problem concerned with Kubo's Linear Response Theory and the strong criticism against it by van Kampen. Kubo's theory is based on a perturbation treatment of the Liouville equation, which, in turn, is expected to be totally equivalent to a first-order perturbation treatment of single trajectories. Since the boosters are chaotic, and chaos is essential to generate diffusion, the single trajectories are highly unstable and do not respond linearly to weak external perturbation. We adopt chaotic maps as boosters of a Brownian particle, and therefore address the problem of the response of a chaotic booster to an external perturbation. We notice that a fully chaotic map is characterized by an invariant measure which is a continuous …
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