BP2 achievements 2013-16: hydrodynamics applied to quark-gluon plasma
Applicability of relativistic hydrodynamics, in particular the role played by non-hydrodynamic modes in describing the process of attaining equilibrium by strongly interacting quantum systems has been clarified [1-5]. The research brought about a novel approach to hydrodynamics as an effective way of describing the process of attaining equilibrium within a wide class of basic theories, regardless whether or not they offer the quasi-particle description . Effective hydrodynamic description of non-equilibrium states has paved some new avenues in quantum theories. Besides, direct applicability of relativistic hydrodynamic to describe evolution of quark-gluon plasma produced in collisions of heavy nuclei in the RHIC and LHC accelerators is also an important aspect.
The results have been based on both analytical calculations and numeric simulations of non-equilibrium phenomena in the super-symmetric Yang-Mills theories . The AdS/CFT correspondence applied in the calculations makes possible to obtain some Yang-Mills theory physical quantities by means of semi-classical calculations in higher-dimensional gravitational models. In such cases one can calculate the spectrum of modes dominating in the process of attaining equilibrium and relate them to behaviour of the hydrodynamic series in higher modes [3,4]. Successful results have also suggested a method to study the spectrum even if non-perturbation calculations in the basic theory are not yet possible . Recently similar ideas have also been applied to models formulated within the framework of the relativistic kinetic theory. Paper  on that subject has been distinguished by editors of the prestigious Physical Review Letters journal.
 Statistics of thermalization in Bjorken Flow, J. Jankowski, G. Plewa and M. Spaliński, JHEP 1412, 105 (2014)
 Coupling hydrodynamics to nonequilibrium degrees of freedom in strongly interacting quark-gluon plasma, M. P. Heller, R. A. Janik, M. Spaliński and P. Witaszczyk, Phys. Rev. Lett. 113, no. 26, 261601 (2014)
 Hydrodynamics Beyond the Gradient Expansion: Resurgence and Resummation, M. P. Heller and M. Spaliński, Phys. Rev. Lett. 115, no. 7, 072501 (2015)
 Resurgence in extended hydrodynamics, I. Aniceto and M. Spaliński, Phys.Rev. D 93 (2016)
 Small systems and regulator dependence in relativistic hydrodynamics, M. Spaliński, Phys. Rev. D 94, 085002 (2016)