Symmetry Obstruction to Fermi Liquid Behavior in the Unitary Limit

Abstract

We show that a Fermi gas, in three dimensions, at temperatures above the superconducting phase transition but below the Fermi temperature, can not be described by Fermi Liquid Theory (FLT) in the unitary limit where the scattering length diverges. The result follows by showing that the there are no effective field theory descriptions that both behave like a Fermi liquid and properly non-linearly realize the spontaneously broken boost and conformal invariance of the system.

Comments: Updated references. Fixed equation for dilatation constraint