Viscosity and damping of collective modes in two-dimensional and scale-invariant Fermi gases

We study the consequences of exact and approximate scale invariance in dilute Fermi gases, with a particular emphasis on fluid dynamics and transport properties. We review recent attempts to extract the shear and bulk viscosity of the dilute Fermi gas in two and three dimensions from the damping of collective excitations. We compare the results to predictions from kinetic theory.