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| Format: | Preprint |
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2024
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| Online Access: | https://arxiv.org/abs/2402.08630 |
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| _version_ | 1866911776405192704 |
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| author | Khurshudyan, Martiros Elizalde, Emilio |
| author_facet | Khurshudyan, Martiros Elizalde, Emilio |
| contents | Recently, using Bayesian Machine Learning, a deviation from the cold dark matter model on cosmological scales has been put forward. Such model might replace a proposed non-gravitational interaction between dark energy and dark matter, and help solve the $H_{0}$ tension problem. The idea behind the learning procedure relied there on a generated expansion rate, while the real expansion rate was just used to validate the learned results. In the present work, however, the emphasis is put on a Gaussian Process (GP) with the available $H(z)$ data confirming the possible existence of the already learned deviation. Three cosmological scenarios are considered: a simple one, with equation of state parameter for dark matter $ω_{dm} = ω_{0} \neq 0$, and two other models, with corresponding parameters $ω_{dm} = ω_{0} + ω_{1} z$ and $ω_{dm} = ω_{0} + ω_{1} z/(1+z)$. The constraints obtained on the free parameters $ω_{0}$ and $ω_{1}$ hint towards a dynamical nature of the deviation. The dark energy dynamics is also reconstructed, revealing interesting aspects connected with the $H_{0}$ tension problem. It is concluded, however, that improved tools and more data are needed, in order to reach a better understanding of the reported deviation. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2402_08630 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Constraints on prospective deviations from the cold dark matter model using a Gaussian Process Khurshudyan, Martiros Elizalde, Emilio General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology High Energy Physics - Theory Recently, using Bayesian Machine Learning, a deviation from the cold dark matter model on cosmological scales has been put forward. Such model might replace a proposed non-gravitational interaction between dark energy and dark matter, and help solve the $H_{0}$ tension problem. The idea behind the learning procedure relied there on a generated expansion rate, while the real expansion rate was just used to validate the learned results. In the present work, however, the emphasis is put on a Gaussian Process (GP) with the available $H(z)$ data confirming the possible existence of the already learned deviation. Three cosmological scenarios are considered: a simple one, with equation of state parameter for dark matter $ω_{dm} = ω_{0} \neq 0$, and two other models, with corresponding parameters $ω_{dm} = ω_{0} + ω_{1} z$ and $ω_{dm} = ω_{0} + ω_{1} z/(1+z)$. The constraints obtained on the free parameters $ω_{0}$ and $ω_{1}$ hint towards a dynamical nature of the deviation. The dark energy dynamics is also reconstructed, revealing interesting aspects connected with the $H_{0}$ tension problem. It is concluded, however, that improved tools and more data are needed, in order to reach a better understanding of the reported deviation. |
| title | Constraints on prospective deviations from the cold dark matter model using a Gaussian Process |
| topic | General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Phenomenology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2402.08630 |