Fermi surface renormalization in two spatial dimensions

We discuss the renormalization induced by interactions of a two-dimensional truncated Fermi surface (FS) model. Using a field-theoretical renormalization group method, we calculate the critical renormalized physical chemical potential $\mu_\ab{R}(\frac{\mu}{\omega};U(\omega))$ which may take different values along the Fermi surface. We show that FS is strongly renormalized by interactions in two dimensions. As a result of that, FS can be further truncated in those $\bm{k}$-space regions where non-trivial fixed points produce a smooth momentum distribution function in the vicinity of the Fermi surface