2 Fundamentals of special relativity 80 2.1 Einstein’s postulates and insights . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 2.2 Time out of joint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 2.3 Spacetime and Lorentz invariance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 2.4 Special relativistic dynamics . . . . . . . . . . . . . . . ...

We evaluate the phonon contribution to the bulk viscosities ζ1, ζ2 and ζ3 of a cold relativistic superfluid. We consider the low temperature T regime assuming that the transport properties of the system are dominated by the phonons. We use kinetic theory in the relaxation time approximation and the low energy effective field theory of the corresponding system. The parametric dependence of the b...

To bracket the importance of the pre-equilibrium stage on relativistic heavy-ion collision observables, we compare simulations where it is modeled by either free-streaming partons or fluid dynamics. These cases implement the assumptions of extremely weak vs. extremely strong coupling in the initial collision stage. Accounting for flow generated in the pre-equilibrium stage, we study the sensiti...

The quark gluon plasma produced in ultrarelativistic heavy-ion collisions exhibits remarkable features. It behaves like a nearly perfect liquid with a small shear viscosity to entropy density ratio and leads to the quenching of highly energetic particles. We show that both effects can be understood for the first time within one common framework. Employing the parton cascade Boltzmann approach t...

Supermassive disks are thought to be precursors of supermassive black holes that are believed to power quasars and exist at centers of galaxies. Formation scenarios of such disks are reviewed and it is argued that gas dynamical schemes are favourable compared to stellar dynamical schemes which could however be important feeding mechanisms for the growth of the black hole. A new self-similar mod...

We present three-dimensional hydrodynamic simulations of the evolution of selfgravitating, thick accretion discs around hyperaccreting stellar-mass black holes. The black hole-torus systems are considered to be remnants of compact object mergers, in which case the disc is not fed by an external mass reservoir and the accretion is non-stationary. Our models take into account viscous dissipation,...

There are interesting parallels between the physics of heavy ion collisions and cosmology. Both systems are out-ofequilibrium and relativistic fluid dynamics plays an important role for their theoretical description. From a comparison one can draw interesting conclusions for both sides. For heavy ion physics it could be rewarding to attempt a theoretical description of fluid perturbations simil...

The nearly perfect fluid-like nature of the Quark Gluon Plasma may be understood through two key experimental signatures: collective flow and jet suppression. Event-by-event relativistic viscous hydrodynamics (with an extremely small shear viscosity to entropy density ratio) has been very successful at describing collective flow observables for the last 7 years. More recently, the effects of ev...

The transport coefficient of shear viscosity is studied for a hadron matter through microscopic transport model, the Ultra–relativistic Quantum Molecular Dynamics (UrQMD), using the Green–Kubo formulas. Molecular– dynamical simulations are performed for a system of light mesons in a box with periodic boundary conditions. Starting from an initial state composed of π, η , ω , ρ , φ with a uniform...

The stationary hydrodynamic equations for the transonic accretion disks and flows around rotating black holes are presented by using the Kerr-Schild coordinate where there is no coordinate singularity at the event horizon. We use two types of the causal viscosity prescription, and the boundary conditions for the transonic accretion flows are given at the sonic point. For one type of the causal ...