Remarks on cosmological bulk viscosity in different epochs

Brevik, Iver; Normann, Ben David

doi:10.48550/arxiv.2006.09514

Cited by 2 publications

(2 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the recent paper Brevik and Normann [43] have obtained the value of m = 1/2 to be distinguished by the current Universe. We have found that cosmological models with viscous matter and without the cosmological term should be structurally stable provided that the parameter m < 1/2.…”

Section: Discussionmentioning

confidence: 99%

Interpretation of bulk viscosity as the generalized Chaplygin gas

Szydlowski,

Krawiec

2020

Preprint

View full text Add to dashboard Cite

The cosmological observations suggest that the presently accelerating universe should be filled by an exotic form of matter, violating the strong energy condition, of unknown nature and origin. We propose the viscous dark matter of a source of acceleration in the form of Chaplygin gas which is characterized by equation of state in the phenomenological form p = − A ρ α , where p and ρ are pressure and energy density respectively (A and α are constants). Chaplygin gas is interpreted in terms of viscous matter and without the cosmological constant. The acceleration effect is caused only by viscosity in this class of cosmological models. We show that bulk viscosity effects introduced to the standard FRW cosmology give rise to the natural unification of both dark matter and dark energy. We show that dust viscous cosmological models are structurally stable if m < 1/2 (1 + α = 1/2 − m).

show abstract

Section: Discussionmentioning

confidence: 99%

Interpretation of bulk viscosity as the generalized Chaplygin gas

Szydlowski,

Krawiec

2020

Preprint

View full text Add to dashboard Cite

show abstract

“…Obtained in such a way fluid with negative pressure we called viscous dark mater. We assume that the viscosity coefficient is parameterized by the Belinskii-Khalatnikov power law form but in a realistic case the parameterization can depend on the cosmological epoch [17].…”

Section: Introductionmentioning

confidence: 99%

Viscous Matter in FRW Cosmology

Szydłowski

Krawiec

2020

Symmetry

View full text Add to dashboard Cite

We investigate the dynamics of dust matter with bulk viscosity effects. We explored the analogy dynamical problem to Chaplygin gas. Due to this analogy we give exact solutions for the FRW cosmology with viscosity coefficient parameterized by the Belinskii–Khalatnikov power law dependence with respect to energy density. These exact solutions are given in the form of hypergeometrical functions. We proved simple theorem which illustrated as viscosity effects can solved the initial singularity problem present in standard cosmological model.

show abstract

Remarks on cosmological bulk viscosity in different epochs

Cited by 2 publications

References 39 publications

Interpretation of bulk viscosity as the generalized Chaplygin gas

Interpretation of bulk viscosity as the generalized Chaplygin gas

Viscous Matter in FRW Cosmology

Contact Info

Product

Resources

About