Description
I will review recent developments, state of the arts and some of the open problems in relativistic
hydrodynamics applied to the deconfined matter of quarks and gluons. I will focus on how the data obtained in heavy
ion collisions is matched onto results of hydrodynamic simulations and how the various transport properties of the
quark-gluon plasma can be obtained through Bayesian analysis. Among the many open problems, I will discuss i)
inclusion of electromagnetic properties of the quark-gluon matter, and, ii) effects of vorticity e.g. explanation of the
recently observed global spin polarization of hadrons through spin transport. These problems urge us to develop a
full-fledged relativistic theory of spin-magneto-hydrodynamics. I will discuss challenges associated to this theory,
and, if time permits also how holography could help solving these challenges.
