Alladi Ramakrishnan Hall

Relativistic hydrodynamics and its applications in heavy-ion collisions

Chandrodoy Chattopadhyay

North Carolina State University

Relativistic heavy-ion collisions at LHC, CERN and RHIC, BNL produce a novel state of matter, the quark-gluon plasma (QGP), where the fundamental constituents of nucleons, i.e., quarks and gluons, become deconfined over nuclear volumes. Understanding
the thermodynamic and transport properties of QGP constitute one of the major goals of high energy nuclear physics. Research over the last two decades has established that the bulk evolution of QGP can be remarkably well-described by relativistic
hydrodynamics. Although it is traditionally believed that hydrodynamics is applicable only for nearly-equilibrated systems, recent discoveries reveal that it may be successful even for far-off-equilibrium stages of heavy-ion collisions. This leads to a
fundamental question pertaining to many-body dynamics: when does a macroscopic system depict hydrodynamic behavior? In this talk I shall present modern formulations of hydrodynamics and use the concept of `non-equilibrium attractors’ to discuss why such
formulations are unreasonably effective beyond their expected domain of applicability. I will then present `maximum-entropy hydrodynamics’, a macroscopic theory which can describe both near and far-off-equilibrium regimes of heavy-ion collisions in a single
framework.