Thermodynamic Susceptibilities for a Unitary Fermi Gas

Abstract

The unitary Fermi gas provides a unique window into both cold atom experiments and neutron star properties. There are major challenges in determining the physical properties within a neutron star, both experimentally and theoretically. However, there is a region within the crust of a neutron star that resembles a gas of fermions that is recreated in a cold atom laboratory. This is the so-called unitary Fermi gas characterized by a large negative scattering length and small effective range. We set out to calculate from first principles certain transport coefficients that appear at second order in the hydrodynamic expansion. These particular transport coefficients are obtained from two point correlation functions in flat space that do not require analytic continuation from Euclidean to Minkowski space. We are motivated by the potential to learn about neutron star properties from cold atom experiments.