Burr, Levy, Tsallis

The purpose of this short paper dedicated to Prof Constantin Tsallis on his 60th anniversary is to show how the use of mathematical tools and physical concepts introduced by Burr, Levy and Tsallis open a new line of analysis of the old problem of non-Debye decay and universality of relaxation. We also show how a finite characteristic time scale can be expressed in terms of a q-expectation using the concept of q-escort probability. The comparison with the Weron et al. probabilistic theory of relaxation leads to a better understanding of the stochastic properties underlying the Tsallis entropy concept. (C) 2004 Elsevier B.V. All rights reserved.