Colloquium – Jean-Francois Paquet – Multi-messenger nuclear physics and microscopic relativistic fluids

The quark-gluon plasma is a new phase of matter that can be produced by colliding large nuclei at velocities close to the speed of light. This plasma is both the smallest and hottest liquid ever produced, extending the size of a few proton radii but reaching temperatures higher than those found in the most extreme astrophysical events. The explosive expansion of this plasma can be described with relativistic fluid dynamics, and provides a window into the equation of state and transport coefficients of strongly coupled nuclear matter. I present constraints on the viscosities of the quark-gluon plasma, obtained through a large-scale Bayesian analysis combining measurements from two collider experiments. I discuss electromagnetic radiation from the quark-gluon plasma and their potential to provide additional constraints on the viscosities.