Weak Chaos from Tsallis Entropy
  We present a geometric, model-independent, argument that aims to explain why the Tsallis entropy describes systems exhibiting "weak chaos", namely systems whose underlying dynamics has vanishing largest Lyapunov exponent. Our argument relies on properties of a deformation map of the reals induced by the Tsallis entropy, and its conclusion agrees with all currently known results. 
Nikos Kalogeropoulos
math-ph cond-mat.stat-mech math.MP nlin.CD