Perturbations with bulk viscosity in modified chaplygin gas cosmology
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arXiv
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| Natura: | Preprint |
| Pubblicazione: |
2024
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| _version_ | 1866912171165745152 |
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| author | Munyeshyaka, Albert Dhankar, Praveen Kumar Ntahompagaze, Joseph |
| author_facet | Munyeshyaka, Albert Dhankar, Praveen Kumar Ntahompagaze, Joseph |
| contents | In the present work, we investigate cosmological perturbations of viscous modified chaplygin gas model. Using 1 + 3 covariant formalism, we define covariant and gauge invariant gradient variables, which after the application of scalar decomposition and harmonic decomposition techniques together with redshift transformation method, provide the energy overdensity perturbation equations in redshift space, responsible for large scale structure formation. In order to analyse the effect of the viscous modified chaplygin gas model on matter overdensity contrast, we numerically solve the perturbation equations in both long and short wavelength limits. The numerical results show that the energy overdensity contrast decays with redshift. However, the perturbations which include amplitude effects due to the viscous modified chaplygin model do differ remarkably from those in the ΛCDM. In the absence of viscous modified chaplygin model, the results reduce to those of ΛCDM. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2411_11309 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Perturbations with bulk viscosity in modified chaplygin gas cosmology Munyeshyaka, Albert Dhankar, Praveen Kumar Ntahompagaze, Joseph General Relativity and Quantum Cosmology 83Dxx, 83Fxx In the present work, we investigate cosmological perturbations of viscous modified chaplygin gas model. Using 1 + 3 covariant formalism, we define covariant and gauge invariant gradient variables, which after the application of scalar decomposition and harmonic decomposition techniques together with redshift transformation method, provide the energy overdensity perturbation equations in redshift space, responsible for large scale structure formation. In order to analyse the effect of the viscous modified chaplygin gas model on matter overdensity contrast, we numerically solve the perturbation equations in both long and short wavelength limits. The numerical results show that the energy overdensity contrast decays with redshift. However, the perturbations which include amplitude effects due to the viscous modified chaplygin model do differ remarkably from those in the ΛCDM. In the absence of viscous modified chaplygin model, the results reduce to those of ΛCDM. |
| title | Perturbations with bulk viscosity in modified chaplygin gas cosmology |
| topic | General Relativity and Quantum Cosmology 83Dxx, 83Fxx |
| url | https://arxiv.org/abs/2411.11309 |