This is a study of composition rule and temperature definition for nonextensive systems containing different q subsystems. The physical meaning of the multiplier β associated with the energy expectation in the optimization of Tsallis entropy is investigated for the formalism with normalized expectation given by escort probability. This study is carried out for two possible cases: the case of th...

The statistical properties of fully developed hydrodynamic turbulence can be successfully described using methods from nonextensive statistical mechanics. The predicted probability densities and scaling exponents precisely coincide with what is measured in various turbulence experiments. As a dynamical basis for nonextensive behaviour we consider nonlinear Langevin equations with fluctuating fr...

We briefly review the present status of nonextensive statistical mechanics. We focus on (i) the central equations of the formalism, (ii) the most recent applications in physics and other sciences, (iii) the a priori determination (from microscopic dynamics) of the entropic index q for two important classes of physical systems, namely low-dimensional maps (both dissipative and conservative) and ...

Superpositions of different statistics on different time or spatial scales (in short, superstatistics) can naturally lead to an effective description by nonextensive statistical mechanics. We first discuss the role of escort distributions within the superstatistical framework, and then briefly describe recent physical applications of this concept to turbulent and patttern forming systems.

We discuss the occurrence of negative specific heat in a nonextensive system which has an equilibrium second-order phase transition. The specific heat is negative only in a transient regime before equilibration , in correspondence to long-lasting metastable states. For these states standard equilibrium Bolzmann-Gibbs thermodynamics does not apply and the system shows non-Gaussian velocity distr...

In this article, the effect of the nonextensivity parameter on the energy fluctuations of nonextensive systems is studied in two different versions of the Tsallis statistical mechanics. Once a general expression has been reported for the energy fluctuations in the second version (Tsallis work in 1988), the energy fluctuations of an ideal gas and a harmonic oscillator are studied in the second a...

We show that the non-additivity relation of the Tsallis entropies in nonextensive statistical mechanics has a simple physical interpretation for systems with fluctuating temperature or fluctuating energy dissipation rate. We also show that there is a distinguished dependence of the entropic index q on the spatial scale that makes the Tsallis entropies quasi-additive. Quasi-additivity implies th...