arXiv subjects

Abraao J. S. Capistrano

Publications and source records attributed to Abraao J. S. Capistrano.

3 recordsLinked to original sources

arXiv2025

Shadows and amplitude luminosity of an embedded rotating black hole

We investigate a rotating black hole embedded in a five-dimensional flat bulk by extending the Kerr metric through the Gurses-Gursey line element. Employing Boyer-Lindquist coordinates, we reinterpret the black hole as a charged-like object in five dimensions and analyze its horizon structure and shadow morphology. Our results reveal that the shadow is shaped by an axially symmetric gravitational field modulated by an extrinsic curvature term arising from the higher-dimensional embedding. Simulations demonstrate that the visibility amplitude and shadow profile of the Gurses-Gursey black hole align with Event Horizon Telescope observations of M87 in the Kerr limit, while also allowing measurable deviations that could be probed by future high-resolution experiments.

gr-qc↗

arXiv2015

Evolving extrinsic curvature and the cosmological constant problem

The concept of smooth deformation of Riemannian manifolds associated with the extrinsic curvature is explained and applied to the FLRW cosmology. We show that such deformation can be derived from Einstein-Hilbert-like dynamical principle producing an observable effect in the sense of Noether. As a result, we notice on how the extrinsic curvature compensates both quantitative and qualitative difference between the cosmological constant $ Λ$ and the vacuum energy $ρ_{vac}$ obtaining the observed upper bound for the cosmological constant problem at electroweak scale. The topological characteristics of the extrinsic curvature are discussed showing that the produced extrinsic scalar curvature is an evolving dynamical quantity.

gr-qc↗

arXiv2014

Weyl conformastatic perihelion advance of small body objects

In this paper, we examine a static gravitational field with axial symmetry over probe particles in the solar system. Using the Weyl conformastatic solution as a model, we find a non-standard expression to perihelion advance due to the constraints imposed by the topology of the local gravitational field. We show that the application of the slow motion condition to the geodesic equations without altering Einstein's equations does not necessarily lead to the Newtonian limit; rather it leads to an intermediate nearly-newtonian gravitational stage, which can be applied to astrophysical problems in solar scale. We apply the model to the perihelion advance of inner planets and minor objects (NEO asteroids and the comets). As a result, we obtain an expression of a non-standard relativistic precession that reveals a close agreement to observational data calibrated with the Ephemerides of the Planets and the Moon (EPM2011). The study of perihelion advance of eight small celestial bodies (asteroids and comets) is also considered.

gr-qc↗