UNIVERSALITY OF TRANSPORT-PROPERTIES IN EQUILIBRIUM, THE GOLDSTONE THEOREM, AND CHIRAL ANOMALY

We study transport in a class of physical systems possessing two conse rved chiral charges. We describe a relation between universality of tr ansport properties of such systems and the chiral anomaly. We show tha t the nonvanishing of a current expectation value implies the presence of gapless modes, in analogy to the Goldstone theorem. Our main tool is a new formula expressing currents in terms of anomalous commutators . Universality of conductance arises as a natural consequence of the n onrenormalization of anomalies. To illustrate our formalism we examine transport properties of a quantum wire in 1 + 1 dimensions and of mas sless QED in a background magnetic field in 3 + 1 dimensions.