Speaker: Johannes Hofmann (University of Gothenburg) Title: Hydrodynamic transport in two-dimensional Fermi liquids Abstract: There is currently much experimental interest in studying transport in ultraclean two-dimensional materials, which is dominated by electron interactions as opposed to the conventional phonon or impurity scattering. This gives rise to an effective hydrodynamic description of electron flow, with transport coefficients (like the shear viscosity) that can be predicted from an underlying Fermi-liquid description. While one could think that this framework should be extremely well understood, it turns out that there are still fundamental aspects that remain unexplored. In this talk, I will give an introduction to Fermi liquids and hydrodynamic transport in 2D materials, and discuss how Pauli blocking gives rise to excitations with lifetimes that are much longer than conventionally expected in Fermi liquid theory. I will then discuss how such long-lived modes will change the conventional hydrodynamic description of the electron fluid.