Nonextensive Thermostatistics and the $H$-Theorem Revisited

In this paper we present a new derivation of the $H$-theorem and the corresponding collisional equilibrium velocity distributions, within the framework of Tsallis’ nonextensive thermostatistics. Unlike previous works, in our derivation we do not assume any modification on the functional form of Boltzmann’s original “molecular chaos hypothesis”. Rather, we explicitly introduce into the collision scenario, the existence of statistical dependence between the molecules before the collision has taken place, through a conditional distribution $f({\vec{v}}_2\mathrm{\mid }{\vec{v}}_1)$. In this approach, different equilibrium scenarios emerge depending on the value of the nonextensive entropic parameter.