# Viscous quark‐gluon plasma in the early universe

@article{Tawfik2011ViscousQP, title={Viscous quark‐gluon plasma in the early universe}, author={A. Tawfik and Mohamed Wahba and H. Mansour and Tiberiu Harko}, journal={Annalen der Physik}, year={2011}, volume={523} }

In the present work a study is given for the evolution of a flat, isotropic and homogeneous Universe, which is filled with a causal bulk viscous cosmological fluid. We describe the viscous properties by an ultra‐relativistic equation of state, and bulk viscosity coefficient obtained from recent lattice QCD calculations. The basic equation for the Hubble parameter is derived by using the energy equation obtained from the assumption of the covariant conservation of the energy‐momentum tensor of…

## 22 Citations

### Viscous cosmologies

- PhysicsClassical and Quantum Gravity
- 2019

We probe into universes filled with quark gluon plasma with non-zero viscosities. In particular, we study the evolution of a universe with non-zero shear viscosity motivated by the theoretical result…

### Thermodynamics of viscous matter and radiation in the early universe

- Physics
- 2012

Assuming that the background geometry is filled with a free gas consisting of matter and radiation and that no phase transitions are occurring in the early universe, we discuss the thermodynamics of…

### Early Universe Thermodynamics and Evolution in Nonviscous and Viscous Strong and Electroweak Epochs: Possible Analytical Solutions

- PhysicsEntropy
- 2021

The possible influence of the bulk viscosity in the early Universe is determined and the rate of decreasing H(a(t)) with increasing a(t) varies from epoch to epoch, at vanishing and finite cosmological constant.

### Thermodynamics in the viscous early universe

- Physics
- 2010

Assuming that the matter in the background geometry is a free gas and that no phase transitions were occurring in the early Universe, we discuss the thermodynamics of this closed system using…

### Transport coefficients of hot magnetized QCD matter beyond the lowest Landau level approximation

- PhysicsThe European Physical Journal C
- 2019

In this article, shear viscosity, bulk viscosity, and thermal conductivity of a QCD medium have been studied in the presence of a strong magnetic field. To model the quark–gluon plasma, an extended…

### Equation of state for cosmological matter at and beyond QCD and electroweak eras

- PhysicsJournal of Physics G: Nuclear and Particle Physics
- 2019

Various thermodynamic quantities for baryon-free matter are calculated by combining the most reliable non-perturbative and perturbative calculations, especially the most recent ones including as many…

### Exploring a matter-dominated model with bulk viscosity to drive the accelerated expansion of the Universe

- Physics
- 2010

We explore the viability of a bulk viscous matter-dominated Universe to explain the present accelerated expansion of the Universe. The model is composed by a pressureless fluid with bulk viscosity of…

### Reliable Equations of State of Viscous Strong and Electroweak Matter

- Physics
- 2019

For the first time, a reliable estimation for the equations of state (EoS), bulk viscosity, and relaxation time, at temperatures ranging from a few MeV up to TeV or energy density up to 10 GeV/fm.…

### Thermodynamical Properties of Quark-Gluon Plasma and Effects of Bulk Viscosity

- Physics
- 2012

In this paper, we use equation of state, temperature and bulk viscosity of the quark gluon plasma and calculate some cosmological and thermodynamical quantities. In order to obtain such quantities we…

### An Estimate of the Thermodynamic Pressure in High-Energy Collisions

- Physics, Mathematics
- 2015

We introduce a novel approach to estimate the thermodynamic pressure from heavy-ion collisions based on recently measured higher-order moments of particle multiplicities by the STAR experiment. We…

## References

SHOWING 1-10 OF 60 REFERENCES

### Viscous dissipative Chaplygin gas dominated homogenous and isotropic cosmological models

- Physics
- 2008

The generalized Chaplygin gas, which interpolates between a high density relativistic era and a nonrelativistic matter phase, is a popular dark energy candidate. We consider a generalization of the…

### Cosmological particle production and casual thermodynamics

- Physics
- 1999

The full linear causal Israel–Stewart–Hiscock theory of bulk viscous processes in relativistic cosmological fluids is reformulated as an effective phenomenological theory for describing particle…

### Viscous Bianchi type I universes in brane cosmology

- Physics
- 2003

We consider the dynamics of a viscous cosmological fluid in the generalized Randall–Sundrum model for an anisotropic, Bianchi type I brane. To describe the dissipative effects we use the…

### Viscous dissipative effects in isotropic brane cosmology

- Physics
- 2001

We consider the dynamics of a viscous cosmological fluid in the generalized Randall-Sundrum model for an isotropic brane. To describe the dissipative effects we use the Israel-Hiscock-Stewart full…

### Renormalization group approach to causal bulk viscous cosmological models

- Physics
- 2001

The renormalization group method is applied to the study of homogeneous and flat Friedmann–Robertson–Walker type universes, filled with a causal bulk viscous cosmological fluid. The starting point of…

### Exact Causal Viscous Cosmologies

- Physics
- 1998

The general exact solution of the gravitational field equations for a homogeneous flat Friedmann-Robertson-Walker universe filled with a causal bulk viscous fluid with bulk viscosity coefficient…

### Heavy ion collisions and lattice QCD at finite baryon density

- Physics
- 2004

We discuss a relation between the
QCD thermodynamics obtained from a statistical analysis of particle production in heavy ion collisions at SPS and RHIC energies and recent LGT results at finite…

### CAUSAL BULK VISCOUS COSMOLOGIES IN CONFORMALLY FLAT SPACETIME

- Physics
- 2000

The evolution of a causal bulk viscous cosmological fluid filled open conformally flat spacetime is considered. By means of appropriate transformations the equation describing the dynamics and…

### Density perturbations with relativistic thermodynamics

- Physics
- 1997

We investigate cosmological density perturbations in a covariant and gauge-invariant formalism, incorporating relativistic causal thermodynamics to give a self-consistent description. The gradient of…