Cosmological Consequences of Varying Couplings in Gravity Action
Fuente:
arXiv
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| Natura: | Preprint |
| Pubblicazione: |
2025
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| _version_ | 1866911209730605056 |
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| author | Sengupta, Sandipan |
| author_facet | Sengupta, Sandipan |
| contents | We develop a Lagrangian formulation for gravity with matter where the gravitational couplings are universally treated as being field-dependent. The solutions for FLRW geometries and the associated time evolution of the Newton and cosmological couplings are found. The distance-redshift relations are shown to prefer a slowly growing Newton's coupling along with a negative equation of state ($w\geq -\frac{1}{3}$) for the matter fluid at the present epoch of accelerated expansion, while ruling out Dirac's large number hypothesis. We obtain an improved bound on $\dot{G}(t)$ as: $1.67\times 10^{-11} yr^{-1}<\frac{\dot{G}}{G}<3.34\times 10^{-11} yr^{-1}$ in the context of supernova cosmology, as well as a new constraint on $\dotΛ(t)$ as: $-0.67\times 10^{-11} yr^{-1}<\frac{\dotΛ}Λ<-1.34\times 10^{-11} yr^{-1}$. Based on this formulation, we also present a dynamical solution to the `cosmic coincidence' problem. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2502_18585 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Cosmological Consequences of Varying Couplings in Gravity Action Sengupta, Sandipan General Relativity and Quantum Cosmology High Energy Physics - Theory We develop a Lagrangian formulation for gravity with matter where the gravitational couplings are universally treated as being field-dependent. The solutions for FLRW geometries and the associated time evolution of the Newton and cosmological couplings are found. The distance-redshift relations are shown to prefer a slowly growing Newton's coupling along with a negative equation of state ($w\geq -\frac{1}{3}$) for the matter fluid at the present epoch of accelerated expansion, while ruling out Dirac's large number hypothesis. We obtain an improved bound on $\dot{G}(t)$ as: $1.67\times 10^{-11} yr^{-1}<\frac{\dot{G}}{G}<3.34\times 10^{-11} yr^{-1}$ in the context of supernova cosmology, as well as a new constraint on $\dotΛ(t)$ as: $-0.67\times 10^{-11} yr^{-1}<\frac{\dotΛ}Λ<-1.34\times 10^{-11} yr^{-1}$. Based on this formulation, we also present a dynamical solution to the `cosmic coincidence' problem. |
| title | Cosmological Consequences of Varying Couplings in Gravity Action |
| topic | General Relativity and Quantum Cosmology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2502.18585 |