How to proceed with nonextensive systems at equilibrium?

Abstract

In this paper, we show that 1) additive energy is not appropriate for discussing the validity of Tsallis or R\'enyi statistics for nonextensive systems at meta-equilibrium; 2) $N$-body systems with nonadditive energy or entropy should be described by generalized statistics whose nature is prescribed by the existence of thermodynamic stationarity. 3) the equivalence of Tsallis and R\'enyi entropies is in general not true.Comment: 14 pages, TEX, no figur