“…We finally investigate the relative entropy with respect to equilibrium that is a natural distance to equilibrium. Relative entropies have been found to be key tools for investigating hyperbolic as well as hyperbolic-parabolic systems [5,7,22,6,41,36,11,26,9,1,20,4]. The relative entropy with respect to equilibrium is nonnegative by the convexity of η and locally behaves quadratically with respect to q.…”