Ultraviolet/infrared mixing in non-Fermi liquids

We study low-energy effective-field theories for non-Fermi liquids with Fermi surfaces of general dimensions and codimensions. When the dimension of the Fermi surface is greater than one, low-energy particle-hole excitations remain strongly coupled with each other across the entire Fermi surface. In this case, even the observables that are local in the momentum space (such as the Green's functions) become dependent on the size of the Fermi surface in singular ways, resulting in a ultraviolet/infrared (UV/IR) mixing. By tuning the dimension and codimension of the Fermi surface independently, we find perturbative non-Fermi-liquid fixed points controlled by both UV/IR mixing and interactions.