Bulk viscous matter and recent acceleration of the universe based on causal viscous theory
Abstract The evolution of the bulk viscous matter dominated universe has been analysed using the full causal theory for the evolution of the viscous pressure in the context of the recent acceleration of the universe. The form of the viscosity is taken as $$\xi =\alpha \rho ^{1/2}. $$ ξ = α ρ 1 / 2 ....
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2017-12-01
|
| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | http://link.springer.com/article/10.1140/epjc/s10052-017-5428-y |
| _version_ | 1818129014486728704 |
|---|---|
| author | N D Jerin Mohan Athira Sasidharan Titus K Mathew |
| author_facet | N D Jerin Mohan Athira Sasidharan Titus K Mathew |
| author_sort | N D Jerin Mohan |
| collection | DOAJ |
| description | Abstract The evolution of the bulk viscous matter dominated universe has been analysed using the full causal theory for the evolution of the viscous pressure in the context of the recent acceleration of the universe. The form of the viscosity is taken as $$\xi =\alpha \rho ^{1/2}. $$ ξ = α ρ 1 / 2 . We obtained analytical solutions for the Hubble parameter and scale factor of the universe. The model parameters have been computed using the observational data. The evolution of the prominent cosmological parameters was obtained. The age of the universe for the best estimated model parameters is found to be less than observational value. The viscous matter behaves like a stiff fluid in the early phase and evolves to a negative pressure fluid in the later phase. The equation of state is found to be stabilised with value $$\omega >- 1.$$ ω > - 1 . The local as well as generalised second law of thermodynamics is satisfied. The statefinder diagnostic shows that this model is distinct from the standard $$\varLambda $$ Λ CDM. One of the marked deviations seen in this model to be compared with the corresponding model using the Eckart approach is that in this model the bulk viscosity decreases with the expansion of the universe, while in the Eckart formalism it increases from negative values in the early universe towards positive values. |
| first_indexed | 2024-12-11T07:42:25Z |
| format | Article |
| id | doaj.art-e2efabb7e1de4c8882a24153643ea100 |
| institution | Directory Open Access Journal |
| issn | 1434-6044 1434-6052 |
| language | English |
| last_indexed | 2024-12-11T07:42:25Z |
| publishDate | 2017-12-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj.art-e2efabb7e1de4c8882a24153643ea1002022-12-22T01:15:32ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60441434-60522017-12-01771211310.1140/epjc/s10052-017-5428-yBulk viscous matter and recent acceleration of the universe based on causal viscous theoryN D Jerin Mohan0Athira Sasidharan1Titus K Mathew2Department of Physics, Cochin University of Science and TechnologyDepartment of Physics, Cochin University of Science and TechnologyDepartment of Physics, Cochin University of Science and TechnologyAbstract The evolution of the bulk viscous matter dominated universe has been analysed using the full causal theory for the evolution of the viscous pressure in the context of the recent acceleration of the universe. The form of the viscosity is taken as $$\xi =\alpha \rho ^{1/2}. $$ ξ = α ρ 1 / 2 . We obtained analytical solutions for the Hubble parameter and scale factor of the universe. The model parameters have been computed using the observational data. The evolution of the prominent cosmological parameters was obtained. The age of the universe for the best estimated model parameters is found to be less than observational value. The viscous matter behaves like a stiff fluid in the early phase and evolves to a negative pressure fluid in the later phase. The equation of state is found to be stabilised with value $$\omega >- 1.$$ ω > - 1 . The local as well as generalised second law of thermodynamics is satisfied. The statefinder diagnostic shows that this model is distinct from the standard $$\varLambda $$ Λ CDM. One of the marked deviations seen in this model to be compared with the corresponding model using the Eckart approach is that in this model the bulk viscosity decreases with the expansion of the universe, while in the Eckart formalism it increases from negative values in the early universe towards positive values.http://link.springer.com/article/10.1140/epjc/s10052-017-5428-y |
| spellingShingle | N D Jerin Mohan Athira Sasidharan Titus K Mathew Bulk viscous matter and recent acceleration of the universe based on causal viscous theory European Physical Journal C: Particles and Fields |
| title | Bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| title_full | Bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| title_fullStr | Bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| title_full_unstemmed | Bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| title_short | Bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| title_sort | bulk viscous matter and recent acceleration of the universe based on causal viscous theory |
| url | http://link.springer.com/article/10.1140/epjc/s10052-017-5428-y |
| work_keys_str_mv | AT ndjerinmohan bulkviscousmatterandrecentaccelerationoftheuniversebasedoncausalviscoustheory AT athirasasidharan bulkviscousmatterandrecentaccelerationoftheuniversebasedoncausalviscoustheory AT tituskmathew bulkviscousmatterandrecentaccelerationoftheuniversebasedoncausalviscoustheory |