Cosmological Constraints on $Λ$(t)CDM Models
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arXiv
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| Autori principali: | , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2023
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| _version_ | 1866914299867299840 |
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| author | Macedo, H. A. P. Brito, L. S. Jesus, J. F. Alves, M. E. S. |
| author_facet | Macedo, H. A. P. Brito, L. S. Jesus, J. F. Alves, M. E. S. |
| contents | Problems with the concordance cosmology $Λ$CDM as the cosmological constant problem, coincidence problems and Hubble tension has led to many proposed alternatives, as the $Λ(t)$CDM, where the now called $Λ$ cosmological term is allowed to vary due to an interaction with pressureless matter. Here, we analyze one class of these proposals, namely, $Λ=α'a^{-2}+βH^2+λ_*$, based on dimensional arguments. Using SNe Ia, cosmic chronometers data plus constraints on $H_0$ from SH0ES and Planck satellite, we constrain the free parameters of this class of models. By using the Planck prior over $H_0$, we conclude that the $λ_*$ term can not be discarded by this analysis, thereby disfavouring models only with the time-variable terms. The SH0ES prior over $H_0$ has an weak evidence in this direction. The subclasses of models with $α'=0$ and with $β=0$ can not be discarded by this analysis. Finally, by using distance priors from CMB, the $Λ$ time-dependence was quite restricted. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2305_18591 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Cosmological Constraints on $Λ$(t)CDM Models Macedo, H. A. P. Brito, L. S. Jesus, J. F. Alves, M. E. S. Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology Problems with the concordance cosmology $Λ$CDM as the cosmological constant problem, coincidence problems and Hubble tension has led to many proposed alternatives, as the $Λ(t)$CDM, where the now called $Λ$ cosmological term is allowed to vary due to an interaction with pressureless matter. Here, we analyze one class of these proposals, namely, $Λ=α'a^{-2}+βH^2+λ_*$, based on dimensional arguments. Using SNe Ia, cosmic chronometers data plus constraints on $H_0$ from SH0ES and Planck satellite, we constrain the free parameters of this class of models. By using the Planck prior over $H_0$, we conclude that the $λ_*$ term can not be discarded by this analysis, thereby disfavouring models only with the time-variable terms. The SH0ES prior over $H_0$ has an weak evidence in this direction. The subclasses of models with $α'=0$ and with $β=0$ can not be discarded by this analysis. Finally, by using distance priors from CMB, the $Λ$ time-dependence was quite restricted. |
| title | Cosmological Constraints on $Λ$(t)CDM Models |
| topic | Cosmology and Nongalactic Astrophysics General Relativity and Quantum Cosmology |
| url | https://arxiv.org/abs/2305.18591 |