How to obtain a class of emergent universes with a general form of dissipation?
Fuente:
arXiv
Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2019
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866914380125306880 |
|---|---|
| author | Saha, Subhajit |
| author_facet | Saha, Subhajit |
| contents | In this paper, we have assumed a flat Friedmann-Lemaitré-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $Π$ which leads to an adiabatic creation of particles induced by the gravitational field. Further, the cosmic substratum is assumed to satisfy the equation of state $p=(γ-1)ρ$ and $Π$ is considered to be proportional to $H^{2k+1}$, where $H$ is the Hubble parameter and $k$ is the index of dissipation. This choice of dissipation is consistent with the pioneering works by Barrow and Clifton. Finally, by assuming an exponential form for $H$ given by $H=e^{m(t-t_0)}$, where $m$ is a positive real parameter and which bears all the signatures of an emergent universe, we have been able to establish that the sufficiency of the inequality $γk \leq 0$ can produce a class of emergent universes. However, this condition is by no means necessary for the existence of an emergent universe. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_1909_07803 |
| institution | arXiv |
| publishDate | 2019 |
| record_format | arxiv |
| spellingShingle | How to obtain a class of emergent universes with a general form of dissipation? Saha, Subhajit General Relativity and Quantum Cosmology In this paper, we have assumed a flat Friedmann-Lemaitré-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $Π$ which leads to an adiabatic creation of particles induced by the gravitational field. Further, the cosmic substratum is assumed to satisfy the equation of state $p=(γ-1)ρ$ and $Π$ is considered to be proportional to $H^{2k+1}$, where $H$ is the Hubble parameter and $k$ is the index of dissipation. This choice of dissipation is consistent with the pioneering works by Barrow and Clifton. Finally, by assuming an exponential form for $H$ given by $H=e^{m(t-t_0)}$, where $m$ is a positive real parameter and which bears all the signatures of an emergent universe, we have been able to establish that the sufficiency of the inequality $γk \leq 0$ can produce a class of emergent universes. However, this condition is by no means necessary for the existence of an emergent universe. |
| title | How to obtain a class of emergent universes with a general form of dissipation? |
| topic | General Relativity and Quantum Cosmology |
| url | https://arxiv.org/abs/1909.07803 |