modes do not decay due to the strong collinear scattering that give rise to rapid equilibration and therefore dominate the long-time dynamics. We make specific predictions for measurements such as the velocity shift of surface acoustic waves, determine the flow of charge and heat in finite geometries, and determine the collective mode spectrum of the system including plasma waves and second-sound-ike thermal waves. The dispersion relations of collective modes can be derived from the poles of transport coefficients, or found from the solutions of the homogeneous quantum Boltzmann equation. Here, focusing on the charge neutrality point, we go beyond the phenomenological treatment of electron-electron interactions of Refs. [@Svintsov2018; @Torre2019]. Our detailed analysis reveals a complex structure of damped collective excitations. These excitations are similar to the so-called “non-hydrodynamic” modes that were shown to be relevant for the equilibration of unitary fermi gases [@Brewer2015] and QCD plasmas [@Romatschke2016; @Romatschke2018; @Heller2018]. In fact, the term non-hydrodynamic is somewhat misleading. What is meant is that these modes correspond to excitations of high angular momentum components of the kinetic distribution function, which are not captured by the Navier-Stokes equations.

Transport in a Dirac fluid is in many respects different from the archetypical example of 