Quarkonia Theory: From Open Quantum System to Classical Transport

This is a theoretical overview of quarkonium production in relativistic heavy ion collisions given for the Hard Probes 2024 conference in Nagasaki. The talk focuses on the application of the open quantum system framework and the formulation of the chromoelectric correlator that uniquely encodes properties of the quark-gluon plasma relevant for quarkonium dynamics and thus can be extracted from theory-experiment comparison.