Hierarchy of rational order families of chaotic maps with an invariant measure

We introduce an interesting hierarchy of rational order chaotic maps that posses an invariant measure. In contrast to the previously introduced hierarchy of chaotic maps \cite{J1,J2,J3,J4,J5}, with merely entropy production, the rational order chaotic maps can simultaneously produce and consume entropy . We compute the Kolmogorov-Sinai entropy of theses maps analytically and also their Lyapunov exponent numerically, where that obtained numerical results support the analytical calculations.