Effective field theory for ersatz Fermi liquids

We apply hydrodynamic effective field theory techniques to an ersatz Fermi liquid (FL). Our effective theory, which captures the correlation functions of density operators at each angle on the Fermi surface, can only deviate from conventional FL behavior if the effective theory is nonlocal. Neglecting nonlocal effects, the effective action of the ersatz FL is the Legendre transform of the effective action for FLs, based on the coadjoint orbit method, up to irrelevant corrections.