ON THE RANDOM VECTOR POTENTIAL MODEL IN 2 DIMENSIONS

The random vector potential model describes massless fermions coupled to a quenched random gauge field. We study its abelian and non-abelian versions, The abelian version can be completely solved using bosonization. We analyse the non-abelian model using its supersymmetric formulation and show, by a perturbative renormalization group computation, that it is asymptotically free at large distances. We also show that all the quenched chiral current correlation functions can be computed exactly, without using the replica trick or the supersymmetric formulation, but using an exact expression for the effective action for any sample of the random gauge field. These chiral correlation functions are purely algebraic.