Kinetic coefficients of the two-dimensional attractive Fermi gas: beyond fermionic quasiparticles

We calculate the static and dynamic shear viscosity and spin diffusion coefficients of a two-dimensional attractive Fermi gas within the Nozi\`eres-Schmitt-Rink approximation, and study their evolution from the weak-coupling Fermi liquid to the strong-coupling composite Bose liquid regime. We find that the inclusion of bosonic contributions in the transport processes is crucial in order to explain the appearance of the hydrodynamic minimum of the kinetic coefficients, as also observed in recent experiments with two-dimensional ultracold Fermi gases.