WEAKLY CORRELATED ELECTRONS ON A SQUARE LATTICE - A RENORMALIZATION-GROUP THEORY

We study the weakly interacting Hubbard model on the square lattice us ing a one-loop renormalization group approach. The transition temperat ure T-c between the metallic and (nearly) ordered states is found. In the parquet regime (T-c much greater than \mu\), the dominant correlat ions at temperatures below T-c are antiferromagnetic, while in the BCS regime (T-c much less than \mu\) at T-c the d-wave singlet pairing su sceptibility is most divergent.