Nonextensive diffusion as nonlinear response
Abstract
The porousmedia equation has been proposed as a phenomenological "nonextensive" generalization of classical diffusion. Here, we show that a very similar equation can be derived, in a systematic manner, for a classical fluid by assuming nonlinear response, i.e. that the diffusive flux depends on gradients of a power of the concentration. The present equation distinguishes from the porousmedia equation in that it describes generalized classical diffusion, i.e. with r/D^{1/2}t scaling, but with a generalized Einstein relation, and with powerlaw probability distributions typical of nonextensive statistical mechanics.
 Publication:

EPL (Europhysics Letters)
 Pub Date:
 September 2005
 DOI:
 10.1209/epl/i200510179x
 arXiv:
 arXiv:condmat/0505216
 Bibcode:
 2005EL.....71..906L
 Keywords:

 Statistical Mechanics
 EPrint:
 Europhys. Lett., 71 (6), pp. 906911 (2005)