Stability of cosmological singularity-free solutions in quadratic gravity
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arXiv
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| Main Authors: | , , |
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| Format: | Preprint |
| Published: |
2024
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| _version_ | 1866917867966955520 |
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| author | Asorey, M. Ezquerro, F. Pardina, M. |
| author_facet | Asorey, M. Ezquerro, F. Pardina, M. |
| contents | We introduce a large family of homogeneous and isotropic cosmological solutions in quadratic gravity which are singularity-free at early and late times. This kind of smooth solutions only emerges beyond the unstable de Sitter branch $3α< β$, $α$ being the coupling of the $R^2$ term and $-β$ the coupling of the $R_{μν}^2$ term. We have analyzed the stability of these singularity-free solutions by computing the second-order variation of the action. The complete analysis shows that a Big Bang can emerge from a singularity-free regime when the parameters of the theory are slightly modified, revealing the unstable nature of this type of solutions. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2412_10111 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Stability of cosmological singularity-free solutions in quadratic gravity Asorey, M. Ezquerro, F. Pardina, M. General Relativity and Quantum Cosmology High Energy Physics - Theory We introduce a large family of homogeneous and isotropic cosmological solutions in quadratic gravity which are singularity-free at early and late times. This kind of smooth solutions only emerges beyond the unstable de Sitter branch $3α< β$, $α$ being the coupling of the $R^2$ term and $-β$ the coupling of the $R_{μν}^2$ term. We have analyzed the stability of these singularity-free solutions by computing the second-order variation of the action. The complete analysis shows that a Big Bang can emerge from a singularity-free regime when the parameters of the theory are slightly modified, revealing the unstable nature of this type of solutions. |
| title | Stability of cosmological singularity-free solutions in quadratic gravity |
| topic | General Relativity and Quantum Cosmology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2412.10111 |