Aleksas Mazeliauskas

Complex many-body systems often display emergent phenomena that cannot be understood solely from the properties of their individual constituents. Key insights into such behavior come from experiments with maximally interacting quantum systems. For example, high-energy collisions at the Large Hadron Collider create dense matter composed of strongly interacting quarks and gluons. Surprisingly, hydrodynamics applies even to the tiny droplets of this quark-gluon plasma—structures thousands of times smaller than a water molecule. Another illustrative example involves ultracold atomic gases confined in optical traps, which also exhibit collective dynamics governed by strong correlations. Out-of-equilibrium quantum systems can display universal features that transcend the details of their microscopic makeup. This universality is often tied to attractor behavior, wherein the system’s evolution becomes largely independent of its initial state. Understanding such attractors is crucial for describing how quantum chromodynamic (QCD) matter thermalizes following high-energy nuclear collisions. In this talk, I will review our current theoretical understanding of QCD thermalization, the emergence of non-thermal and hydrodynamic attractors, and the universal behaviors shared across strongly correlated quantum systems.