Alleviating both $H_0$ and $σ_8$ tensions in Tsallis cosmology
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arXiv
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| Autores principales: | , , , |
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| Formato: | Preprint |
| Publicado: |
2023
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| _version_ | 1866914726903021568 |
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| author | Basilakos, Spyros Lymperis, Andreas Petronikolou, Maria Saridakis, Emmanuel N. |
| author_facet | Basilakos, Spyros Lymperis, Andreas Petronikolou, Maria Saridakis, Emmanuel N. |
| contents | We present how Tsallis cosmology can alleviate both $H_0$ and $σ_8$ tensions simultaneously. Such a modified cosmological scenario is obtained by the application of the gravity-thermodynamics conjecture, but using the non-additive Tsallis entropy, instead of the standard Bekenstein-Hawking one. Hence, one obtains modified Friedmann equations, with extra terms that depend on the new Tsallis exponent $δ$ that quantifies the departure from standard entropy. We show that for particular $δ$ choices we can obtain a phantom effective dark energy, which is known to be one of the sufficient mechanisms that can alleviate $H_0$ tension. Additionally, for the same parameter choice we obtain an increased friction term and an effective Newton's constant smaller than the usual one, and thus the $σ_8$ tension is also solved. These features act as a significant advantage of Tsallis modified cosmology. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2308_01200 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Alleviating both $H_0$ and $σ_8$ tensions in Tsallis cosmology Basilakos, Spyros Lymperis, Andreas Petronikolou, Maria Saridakis, Emmanuel N. General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Theory We present how Tsallis cosmology can alleviate both $H_0$ and $σ_8$ tensions simultaneously. Such a modified cosmological scenario is obtained by the application of the gravity-thermodynamics conjecture, but using the non-additive Tsallis entropy, instead of the standard Bekenstein-Hawking one. Hence, one obtains modified Friedmann equations, with extra terms that depend on the new Tsallis exponent $δ$ that quantifies the departure from standard entropy. We show that for particular $δ$ choices we can obtain a phantom effective dark energy, which is known to be one of the sufficient mechanisms that can alleviate $H_0$ tension. Additionally, for the same parameter choice we obtain an increased friction term and an effective Newton's constant smaller than the usual one, and thus the $σ_8$ tension is also solved. These features act as a significant advantage of Tsallis modified cosmology. |
| title | Alleviating both $H_0$ and $σ_8$ tensions in Tsallis cosmology |
| topic | General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics High Energy Physics - Theory |
| url | https://arxiv.org/abs/2308.01200 |