  For tomographic studies of relativistic nuclear collisions and of the
quark-gluon plasma, photons (real and virtual) are unique. They are the only
probes than can be both soft and penetrating. First we report on advances in
modelling the hadron dynamics of heavy-ion collisions using a hybrid approach
which consists of IP-Glasma, relativistic fluid dynamics, and hadronic cascade
components. We briefly discuss the "photon flow puzzle", and then focus on a
recent development in the theory of photon emission from a non-equilibrium,
strongly interacting medium.

High Energy Physics - Phenomenology;Nuclear Experiment;Nuclear Theory