q-Thermostatistics and the black-body radiation problem
  We give an exact information-theory treatment of the $n$-dimensional black-body radiation process in a non-extensive scenario. We develop a $q$ generalization of the laws of i) Stefan Boltzmann, ii) Planck, and iii) Wien, and show that conventional, canonical results are obtained at temperatures above $1 K$. Classical relationships between radiation, pressure, and internal energy are recovered (independently of the $q$-value). Analyzing the particles' density for $q\approx 1$ we see that the non-extensive parameter $q$ introduces a fictitious chemical potential. We apply our results to experimental data on the cosmic microwave background and reproduce it with acceptable accuracy for different temperatures (each one associated to a particular $q$ value 
S. Martinez, F. Pennini, C. Tessone, A. Plastino