Zobrazeno 1 - 10
of 1 580
pro vyhledávání: '"Lobo, Francisco"'
Autor:
Junior, Ednaldo L. B., Junior, José Tarciso S. S., Lobo, Francisco S. N., Rodrigues, Manuel E., Rubiera-Garcia, Diego, da Silva, Luís F. Dias, Vieira, Henrique A.
We consider a recently introduced extension of General Relativity dubbed as Cotton gravity (CG), based on the use of the Cotton tensor, to estimate the size of a new constant $\gamma$ appearing within a spherically symmetric, vacuum solution of the t
Externí odkaz:
http://arxiv.org/abs/2407.21655
Autor:
Junior, Ednaldo L. B., Junior, José Tarciso S. S., Lobo, Francisco S. N., Rodrigues, Manuel E., Rubiera-Garcia, Diego, da Silva, Luís F. Dias, Vieira, Henrique A.
Recently, J. Harada proposed a theory relating gravity to the Cotton tensor, dubbed as ''Cotton gravity'' (CG). This is an extension of General Relativity such that every solution of the latter turns out to be a solution of the former (but the conver
Externí odkaz:
http://arxiv.org/abs/2407.21649
Publikováno v:
Symmetry 16, 881 (2024)
Since the development of Brans-Dicke gravity, it has become well-known that a conformal transformation of the metric can reformulate this theory, transferring the coupling of the scalar field from the Ricci scalar to the matter sector. Specifically,
Externí odkaz:
http://arxiv.org/abs/2407.08320
Publikováno v:
Phys. Lett. B 856, 138892 (2024)
This Letter aims to advance unexplored properties of a new class of Closed Timelike Curves recently discovered in scalar-tensor gravity, reported in Universe 9, 467 (2023) and Eur.$\,$Phys.$\,$J.$\,$C 83, 626 (2023). Therein, it was shown that when t
Externí odkaz:
http://arxiv.org/abs/2405.12397
Publikováno v:
Eur. Phys. J. C 84, 557 (2024)
In this work, we analyse black bounce solutions in the recently proposed ``Conformal Killing gravity'' (CKG), by coupling the theory to nonlinear electrodynamics (NLED) and scalar fields. The original motivation of the theory was essentially to fulfi
Externí odkaz:
http://arxiv.org/abs/2405.09702
Autor:
Junior, Ednaldo L. B., Junior, José Tarciso S. S., Lobo, Francisco S. N., Rodrigues, Manuel E., Rubiera-Garcia, Diego, da Silva, Luís F. Dias, Vieira, Henrique A.
In this work, we study timelike and lightlike geodesics in Kalb-Ramond (KR) gravity around a black hole with the goal of constraining the Lorentz symmetry-breaking parameter $l$. The analysis involves studying the precession of the S2 star periastron
Externí odkaz:
http://arxiv.org/abs/2405.03291
Autor:
Junior, Ednaldo L. B., Junior, José Tarciso S. S., Lobo, Francisco S. N., Rodrigues, Manuel E., Rubiera-Garcia, Diego, da Silva, Luís F. Dias, Vieira, Henrique A.
Publikováno v:
Phys. Rev. D 110, 024077 (2024)
In this paper, we investigate the gravitational lensing effect for the Schwarzschild-like black hole spacetime in the background of a Kalb-Ramond (KR) field proposed in [K. Yang et. al., Phys. Rev. D 108 (2023) 124004]. The solution is characterized
Externí odkaz:
http://arxiv.org/abs/2405.03284
Publikováno v:
Eur. Phys. J. C 84, 332 (2024)
In this work, we consider an extension of the symmetric teleparallel equivalent of General Relativity (STEGR), namely, $f(\mathbb{Q})$ gravity, by including a boundary term $\mathbb{B}_Q$, where $\mathbb{Q}$ is the non-metricity scalar. More specific
Externí odkaz:
http://arxiv.org/abs/2402.02534
Publikováno v:
Phys. Rev. D 109, 084002 (2024)
In this work, we analyze the observational properties of thin-shell gravastars under two astrophysical frameworks, namely surrounded by optically-thin accretion disks and orbited by hot-spots. We consider the thin-shell gravastar model with two free
Externí odkaz:
http://arxiv.org/abs/2401.07766
Autor:
Junior, Ednaldo L. B., Junior, José Tarciso S. S., Lobo, Francisco S. N., Rodrigues, Manuel E., da Silva, Luís F. Dias, Vieira, Henrique A.
The geodesic method has played a crucial role in understanding the circular orbits generated by compact objects, culminating in the definition of the photon sphere, which was later generalized to a photon surface in arbitrary spacetimes. This new for
Externí odkaz:
http://arxiv.org/abs/2401.01821