A non-critical string approach to black holes, time and quantum dynamics

We review our approach to time and quantum dynamics based on non-critical string theory, developing its relationship to previous work on non-equilibrium quantum statistical mechanics and the microscopic arrow of time. We exhibit specific non-factorizing contributions to the {\nd S} matrix associated with topological defects on the world sheet, explaining the r\^ole that the leakage of {W_{\infty}} charges plays in the loss of quantum coherence. We stress the analogy with the quantum Hall effect, discuss the violation of CPT, and also apply our approach to cosmology.