Stable first-order particle-frame relativistic hydrodynamics for dissipative systems

We propose a stable first-order relativistic dissipative hydrodynamic equation in the particle frame (Eckart frame) for the first time. The equation to be proposed was in fact previously derived by the authors and a collaborator from the relativistic Boltzmann equation. We demonstrate that the equilibrium state is stable with respect to the time evolution described by our hydrodynamic equation in the particle frame. Our equation may be a proper starting point for constructing second-order causal relativistic hydrodynamics, to replace Eckart's particle-flow theory.     

Simple solutions of relativistic hydrodynamics for cylindrically symmetric systems

Simple, self-similar, analytic solutions of 1+3-dimensional relativistic hydrodynamics are presented for cylindrically symmetric fireballs corresponding to central collisions of heavy ions at relativistic bombarding energies.     

Simple solutions of relativistic hydrodynamics for longitudinally expanding systems

Simple, self-similar, analytic solutions of 1+1-dimensional relativistic hydrodynamics are presented, generalizing Bjorken's solution to inhomogeneous rapidity distribution.     

Fluctuations in relativistic hydrodynamics

Czechoslovak Journal of Physics -     

Simple solutions of relativistic hydrodynamics for systems with ellipsoidal symmetry

Simple, self-similar, analytic solutions of (1+3)-dimensional relativistic hydrodynamics are presented for ellipsoidally symmetric finite fireballs corresponding to non-central collisions of heavy ions at relativistic bombarding energies. The hydrodynamical solutions are obtained for a new, general family of equations of state with the possibility of describing phase transitions.     

Non-equilibrium effects in relativistic hydrodynamics

We review Smoothed Particle Hydrodynamics (SPH) for ultrarelativistic nuclear collisions. Possible extensions of the usual formulation are discussed, incorporating the fundamentally important single-event fluctuations originating in turbulent or quantum mechanical motion.     

Adaptive-mesh radiation hydrodynamics—II. The radiation and fluid equations in relativistic flows

We derive the radiation and fluid equations for relativistic flows in conservative from in a completely adaptive coordinate system.     

Canonical formulation of relativistic hydrodynamics

Canonical formulation of the relativistic theory of perfect fluids is given. As an introduction to this subject the canonical formalism for charged particles interacting with electromagnetic field is briefly discussed. Relativistic hydrodynamics is studied in several versions including hydrodynamics of charged fluids coupled to the electromagnetic field and ultrarelativistic hydrodynamics. Ultrarelativistic hydrodynamics is shown to be conformally invariant and several implications of conformal symmetry are discussed.     

On freeze-out problem in relativistic hydrodynamics

A finite unbound system which is equilibrium in one reference frame is in general nonequilibrium in another frame. This is a consequence of the relative character of the time synchronization in the relativistic physics. This puzzle was a prime motivation of the Cooper-Frye approach to the freeze-out in relativistic hydrodynamics. Solution of the puzzle reveals that the Cooper-Frye recipe is far not a unique phenomenological method that meets requirements of energy-momentum conservation. Alternative freeze-out recipes are considered and discussed. The text was submitted by the authors in English.     

Goldstone boson counting in relativistic systems at finite density

We study the effects of finite chemical potential on the pattern of symmetry breaking within the relativistic linear sigma model. In accordance with previous works we show that type-II Goldstone bosons may appear whose dispersion relation is quadratic in momentum in the long-wavelength limit. We show that their presence is tightly connected with nonzero densities of non-Abelian Noether charges, and formulate a general counting rule for the number of the Goldstone bosons. Working at tree level, we conclude with the discussion of the loop effects. Our results find an application in particular to cold dense quark matter, where a type-II Goldstone boson has been found, e.g., in the phases with kaon condensation.     

A variational formulation of relativistic hydrodynamics

We combine Taub's and Ray's variational approaches to relativistic hydrodynamics of perfect fluids into another simple formulation.     

Generalized hydrodynamics from relativistic kinetic theory

The problem is considered of extending the Chapman-Enskog solution of the linearized transport equation for a relativistic quantum gas to the transition regime. The particular system studied is composed of various kinds of particles between which reactive processes are allowed. Following the classical approach of Ernst and Bixon, Dorfman and Mo, we construct a normal solution, as in the Chapman-Enskog procedure, but without any restriction on the wave lengths of the macroscopic disturbances. The method makes use of Zwanzig's projection-operator technique and yields a closed set of hydrodynamic equations with dissipative terms expressed as memory kernels. For small frequencies and wave vectors we recover the linearized Navier-Stokes equations with static transport coefficients given by the usual Chapman-Enskog expressions. Special attention is paid to the thermodynamic fluctuations as described by the static susceptibility matrix.     

Robust particle methods for relativistic hydrodynamics

In this paper we describe how the equations of relativistic fluid dynamics can be solved numerically using the particle method SPH.     

Bouncing scenario of general relativistic hydrodynamics in extended gravity

In this paper,we have framed bouncing cosmological model of the Universe in the presence of general relativistic hydrodynamics in an extended theory of gravity.The metric assumed here is the flat Friedmann–Robertson–Walker space–time and the stress energy tensor is of perfect fluid.Since general relativity(GR)has certain issues with late time cosmic speed up phenomena,here we have introduced an additional matter geometry coupling that described the extended gravity to GR.The dynamical parameters are derived and analyzed.The dynamical behavior of the equation of state parameter has been analyzed.We have observed that the bouncing behavior is mostly controlled by the coupling parameter.     

Hubble-like flows in relativistic heavy-ion collisions

We study the dynamical appearance of scaling solutions in relativistic hydrodynamics. The phase transition effects are included through the temperature dependent sound velocity. If a pre-equilibrium transverse flow is included in the initial conditions, then it may reach the form of the asymptotic Hubble flow, r/t, in short evolution times, 7–15 fm. The numerical solutions are found to support the freeze-out models (Blast-Wave, Buda-Lund, Cracow).     

Induced anomalous current in relativistic hydrodynamics with chiral anomaly

We discuss the triangle anomalous hydrodynamics in the presence of an external magnetic field B ^??. Without loss of generality, we consider the case of a conserved vector current and non-conserved axial current. In order to ensure the positivity of the entropy production rate, two new terms proportional to the magnetic field B ^?? and the vorticity ?? ^??, which are associated with the Chiral Magnetic Effect and Chiral Vortical Effect in heavy ion collisions, need to be introduced. The transport coefficients of these new terms are also determined by the entropy principle.