DIFFUSION IN NORMAL AND CRITICAL TRANSIENT CHAOS

Within the framework of a 1D model we study systems which are extended in certain directions but are restricted in size and open in other di rections. Besides the coefficient D characterizing diffusion on the ch aotic repeller, a coefficient (D) over cap is introduced to measure th e broadening of the distribution of trajectories during the transientl y chaotic motion and is expressed in terms of the correlation function suitably defined for transient chaos. It is shown that there is a sit uation where two smooth conditionally invariant measures exist resulti ng in nonuniqueness of both diffusion coefficients.