Shadows of black holes at cosmological distances in the co-varying physical couplings framework
| Autor: | Cuzinatto, R. R., de Melo, C. A. M., Neves, Juliano C. S. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | MNRAS 526 (3), 3987-3993 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stad2954 |
| Popis: | The co-varying physical couplings (CPC) framework states that physical parameters like the speed of light in vacuum $c$, the Newtonian constant $G$, and the cosmological constant $\Lambda$ could indeed vary with the spacetime coordinates $x^{\mu}$. Here, we assume a temporal variation, that is, $c(t),G(t)$ and $\Lambda(t)$. We show that the McVittie spacetime, a black hole in an expanding universe, is a solution of the CPC framework providing naturally an important parameter of the model. Then, we calculate the shadow angular radius of this black hole at cosmological distances. A black hole shadow in the CPC context could be either larger or smaller than the same shadow in the standard cosmology. It depends on how the set $\{ c,G,\Lambda \}$ varies with time or with the cosmic expansion. Comment: 10 pages, 2 figures. Published in Monthly Notices of the Royal Astronomical Society |
| Databáze: | arXiv |
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