Dynamical scenario for nonextensive statistical mechanics

TL;DR

This paper proposes a dynamical framework for nonextensive statistical mechanics, linking the entropic index to microscopic dynamics and initial condition sensitivity, explaining anomalous stationary states.

Contribution

It introduces a scenario connecting the entropic index q to microscopic dynamics, initial condition sensitivity, and anomalous stationary states in nonextensive systems.

Findings

Provides a hypothesis for the origin of the entropic index q.

Links sensitivity to initial conditions with nonextensive behavior.

Explains the nature of anomalous stationary states.

Abstract

Statistical mechanics can only be ultimately justified in terms of microscopic dynamics (classical, quantum, relativistic, or any other). It is known that Boltzmann-Gibbs statistics is based on the hypothesis of exponential sensitivity to the initial conditions, mixing and ergodicity in Gibbs $\Gamma$-space. What are the corresponding hypothesis for nonextensive statistical mechanics? A scenario for answering such question is advanced, which naturally includes the {\it a priori} determination of the entropic index $q$, as well as its cause and manifestations, for say many-body Hamiltonian systems, in (i) sensitivity to the initial conditions in Gibbs $\Gamma$-space, (ii) relaxation of macroscopic quantities towards their values in anomalous stationary states that differ from the usual thermal equilibrium (e.g., in some classes of metastable or quasi-stationary states), and (iii) energy distribution in the $\Gamma$-space for the same anomalous stationary states.