Universal Hydrodynamic Transport Times in the Normal Phase of a Unitary Fermi Gas

We determine the hydrodynamic relaxation times τ_η for the shear viscosity and τ_κ for the thermal conductivity in the normal phase of a unitary Fermi gas confined in a box potential. Using a kinetic theory relaxation model, we extract τ_η and τ_κ from the time-dependent free-decay of a spatially periodic density perturbation, yielding the universal density-shift coefficients for the shear viscosity and thermal conductivity.