activity
20202026
most citedCan different black holes cast the same shadow?

119 citations · 266 across the 15 of their papers we have counts for

collaborators

15 papers

gr-qc2026

Inspirals into bosonic dark matter stars and chirp mimickers

Caio F. B. Macedo, Haroldo C. D. Lima, Raissa F. P. Mendes +2

We investigate extreme--mass--ratio inspirals in which a stellar-mass compact object orbits a supermassive bosonic dark matter star, modeled as a boson star, using fully relativist…

gr-qc2026

Two shadows of a single black hole: Vacuum birefringence phenomena within Einstein-nonlinear-electrodynamics

Marco A. A. de Paula, Haroldo C. D. Lima, Pedro V. P. Cunha +2

One of the main features of nonlinear electrodynamics is the existence of an effective geometry that describes the geodesic motion of photons. A detailed analysis of the properties…

gr-qc2025

Spherical Einstein-Friedberg-Lee-Sirlin boson stars: Self-interacting solutions and their astrophysical appearance

Pedro L. Brito de Sá, Haroldo C. D. Lima, Carlos A. R. Herdeiro +1

We investigate boson stars within the framework of the self-interacting Einstein-Friedberg-Lee-Sirlin (E-FLS) model, constituted by a complex scalar field with a quartic self-inter…

gr-qc2025

Resolving space-time singularities in spherically symmetric black holes: geodesic completeness, curvature scalars, and tidal forces

Haroldo C. D. Lima Junior, Renan B. Magalhães, Gonzalo J. Olmo +1

The existence of black holes in the Universe is nowadays established on the grounds of a blench of astrophysical observations, most notably those of gravitational waves from binary…

gr-qc2024★ 6 cited

Good tachyons, bad bradyons: role reversal in Einstein-nonlinear-electrodynamics models

Marco A. A. de Paula, Haroldo C. D. Lima Junior, Pedro V. P. Cunha +2

In relativistic mechanics, the 4-velocity and the 4-momentum need not be parallel. This allows their norm to have a different sign. This possibility occurs in nonlinear electrodyna…

gr-qc2024

Static boson stars in the Einstein-Friedberg-Lee-Sirlin theory and their astrophysical images

Pedro L. Brito de Sá, Haroldo C. D. Lima, Carlos A. R. Herdeiro +1

We investigate the static boson star solutions in the so-called Einstein-Friedberg-Lee-Sirlin (E-FLS) theory, performing a complete analysis of the solution space in this model. We…

gr-qc2024

Singular space-times with bounded algebraic curvature scalars

Renan B. Magalhães, Gabriel P. Ribeiro, Haroldo C. D. Lima Junior +2

We show that the absence of unbounded algebraic curvature invariants constructed from polynomials of the Riemann tensor cannot guarantee the absence of strong singularities. As a c…

gr-qc2023

Electrically charged regular black holes in nonlinear electrodynamics: light rings, shadows and gravitational lensing

Marco A. A. de Paula, Haroldo C. D. Lima Junior, Pedro V. P. Cunha +1

Within nonlinear electrodynamics (NED), photons follow null geodesics of an effective geometry, which is different from the geometry of the spacetime itself. Over the last years, s…

gr-qc2023★ 70 cited

Shadows of black holes with dark matter halo

Sérgio V. M. C. B. Xavier, Haroldo C. D. Lima Junior, Luís C. B. Crispino

We investigate the shadow of an exact black hole solution of Einstein's equations recently proposed by Cardoso et al., to describe a supermassive black hole immersed in a dark matt…

gr-qc2023★ 47 cited

Quasinormal modes of a holonomy corrected Schwarzschild black hole

Zeus S. Moreira, Haroldo C. D. Lima Junior, Luís C. B. Crispino +1

We analyze the quasinormal modes (QNMs) of a recently obtained solution of a Schwarzschild black hole (BH) with corrections motivated by Loop Quantum Gravity (LQG). This spacetime…

gr-qc2022★ 23 cited

Tidal forces in dirty black hole spacetimes

Haroldo C. D. Lima Junior, Mateus M. Corrêa, Caio F. B. Macedo +1

Black holes can be inserted in very rich astrophysical environments, such as accretion disks. Although isolated black holes are simple objects in general relativity, their accretio…

gr-qc2021★ 1 cited

Einstein-Maxwell-dilaton neutral black holes in strong magnetic fields: topological charge, shadows and lensing

Haroldo C. D. Lima Junior, Jian-Zhi Yang, Luís C. B. Crispino +2

The light rings (LRs) topological charge (TC) of a spacetime measures the number of stable LRs minus the number of unstable LRs. It is invariant under smooth spacetime deformations…

gr-qc2021★ 119 cited

Can different black holes cast the same shadow?

Haroldo C. D. Lima Junior, Luís C. B. Crispino, Pedro V. P. Cunha +1

We consider the following question: may two different black holes (BHs) cast exactly the same shadow? In spherical symmetry, we show the necessary and sufficient condition for a st…

gr-qc2020

Tidal forces in the charged Hayward black hole spacetime

Haroldo C. D. Lima Junior, Luís C. B. Crispino

Tidal forces produced by black holes are an important result of General Relativity, related to the spacetime curvature tensor. Among the astrophysical implications of tidal forces,…

gr-qc2020

On-Axis Tidal Forces in Kerr Spacetime

Haroldo C. D. Lima Junior, Luís C. B. Crispino, Atsushi Higuchi

Tidal forces are an important feature of General Relativity, which are related to the curvature tensor. We analyze the tidal tensor in Kerr spacetime, with emphasis on the case alo…