Zobrazeno 1 - 10
of 141
pro vyhledávání: '"Rodrigues, Davi C."'
We investigate the cosmological coupling of spherical, local astrophysical systems. We derive a general formula quantifying the cosmological coupling of the Misner-Sharp mass of these objects. We show that, in the weak-field limit, the cosmological c
Externí odkaz:
http://arxiv.org/abs/2406.06091
We explore the possibility of a consistent cosmology based on the gauge-fixing independent running of the gravitational and cosmological constants ($G$ and $\Lambda$) in the framework of effective quantum gravity. In particular, their running in this
Externí odkaz:
http://arxiv.org/abs/2401.11559
Publikováno v:
Phys. Rev. D 109, 044045 (2024)
Massive Brans-Dicke (BD) theory is among the simplest general relativity extensions. It is commonly found as the weak-field limit of other gravitational theories. Here we do a detailed post-Newtonian analysis of massive BD theories. We start by expan
Externí odkaz:
http://arxiv.org/abs/2307.11883
Publikováno v:
MNRAS, 528 (2024) 2
We test the possibility that the black holes (BHs) detected by LIGO-Virgo-KAGRA (LVK) may be cosmologically coupled and grow in mass proportionally to the cosmological scale factor to some power $k$, which may also act as the dark energy source if $k
Externí odkaz:
http://arxiv.org/abs/2307.02474
Publikováno v:
Int. J. Geom. Methods Mod. Phys. 2450028 (2023)
Palatini $f(R)$ gravity is probably the simplest extension of general relativity (GR) and the simplest realization of a metric-affine theory. It has the same number of degrees of freedom as GR and, in vacuum, it is straightforwardly mapped into GR wi
Externí odkaz:
http://arxiv.org/abs/2306.04475
Publikováno v:
Phys. Dark Univ. 41 (2023) 101230
We propose a complementary and fast approach to study galaxy rotation curves directly from the sample data, instead of individual fits. With this approach, some relevant tests can be done analytically. It is based on a dimensionless difference betwee
Externí odkaz:
http://arxiv.org/abs/2204.03762
Autor:
Toniato, Júnior D., Rodrigues, Davi C.
Publikováno v:
Phys. Rev. D 104, 044020 (2021)
We review the fundamentals and highlight the differences between some commonly used definitions for the PPN gamma parameter ($\gamma$) and the gravitational slip ($\eta$). Here we stress the usefulness of a gamma-like parameter used by Berry and Gair
Externí odkaz:
http://arxiv.org/abs/2106.12542
Publikováno v:
Phys. Rev. D 105, 023509 (2022)
We consider an action for gravity that, in addition to the Einstein-Hilbert term, contains a function of the Ricci scalar and the Gauss-Bonnet invariant. The specific form of the function considered is motivated by holographic cosmology. At backgroun
Externí odkaz:
http://arxiv.org/abs/2012.05154
Rastall introduced a stress-energy tensor whose divergence is proportional to the gradient of the Ricci scalar. This proposal leads to a change in the form of the field equations of General Relativity, but it preserves the number of degrees of freedo
Externí odkaz:
http://arxiv.org/abs/2011.10503
Publikováno v:
Phys. Rev. D 102, 123505 (2020); Phys. Rev. D 105, 129901 (2022) (Erratum)
We consider an inflationary scenario in the holographic braneworld with a cosmological fluid occupying the 3+1 dimensional brane located at the holographic boundary of an asymptotic ADS$_5$ bulk. The contribution of the boundary conformal field can b
Externí odkaz:
http://arxiv.org/abs/2007.02332