THE EFFECTIVE GAUGE FIELD ACTION OF A SYSTEM OF NONRELATIVISTIC ELECTRONS

We consider a system of free, non-relativistic electrons at zero tempe rature and positive density, coupled to an arbitrary, external electro magnetic vector potential, A. By integrating out the electron degrees of freedom we obtain the effective action for A. We show that, in the scaling limit, this effective action is quadratic in A and can be view ed as an integral over the Fermi sphere of effective actions of (1 + 1 )-dimensional, chiral Schwinger models. We use this result to elucidat e Luther-Haldane bosonization of systems of non-relativistic electrons . We also study systems of weakly coupled interacting electrons for wh ich the BCS channel is turned off. Using the quadratic dependence of t he effective action on A, we show that, in the scaling limit, the RPA yields the dominant contribution.