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20162026
most citedLight ring stability in ultra-compact objects

384 citations · 1.7k across the 22 of their papers we have counts for

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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

Backreaction of perturbations around a stable Light Ring

Pedro V. P. Cunha

Light rings (LRs) - closed circular orbits of null geodesics - are key features of both black holes and horizonless ultracompact objects. While unstable LRs are relevant for the ob…

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

Breaking the north-south symmetry: dyonic spinning black holes with synchronized gauged scalar hair

Pedro V. P. Cunha, Carlos A. R. Herdeiro, Eugen Radu +1

We study stationary clouds of a gauged, complex scalar field on a magnetically (and possibly electrically as well) charged Kerr-Newman black hole (BH). The existence of a magnetic…

gr-qc2024

Hypershadows of higher dimensional black objects: a case study of cohomogeneity-one d=5 Myers-Perry

João P. A. Novo, Pedro V. P. Cunha, Carlos A. R. Herdeiro

What does a black hole look like? In 1+3 spacetime dimensions, the optical appearance of a black hole is a bidimensional region in the observer's sky often called the black hole sh…

gr-qc2024

Analytical proxy to families of numerical solutions: the case study of spherical mini-boson stars

Jianzhi Yang, Pedro V. P. Cunha, Carlos A. R. Herdeiro

The Einstein field equations, or generalizations thereof, are difficult to solve analytically. On the other hand, numerical solutions of the same equations have become increasingly…