FERMION CURRENT-CURRENT INTERACTIONS AND ORTHOGONALITY IN 2 DIMENSIONS

The wavefunction renormalization Z of a two-dimensional Fermi gas with current-current interaction mediated by an unscreened transverse gaug e held is discussed within a simple Hartree approximation for self-fie ld effects. in the case of a three-dimensional gauge field, a critical coupling strength is required before level crossing and strict orthog onality occur. In the case of a two-dimensional gauge field, any finit e coupling guarantees orthogonality beyond a critical system size.