Tsallis and Renyi entropies in fractional diffusion and entropy production

The entropy production rate for fractional diffusion processes using Shannon entropy was calculated previously, which showed an apparently counter intuitive increase with the transition from dissipative diffusion behaviour to reversible wave propagation. Renyi and Tsallis entropies, which have an additional parameter q generalizing the Shannon case (q = 1), are shown here to have similar counter intuitive behaviours. However, the issue can be successfully treated in exactly the same manner as with Shannon entropy for q being not too large (i.e., generalizations near the Shannon case), whereas for larger q the Renyi and Tsallis entropies behave in a different way. (C) 2000 Elsevier Science B.V. All rights reserved.