In this work, we obtain the shadow images of spherically symmetric scalar boson and Proca
stars using analytical fittings of numerical solutions, when illuminated by a geometrically thin …

We study the light rings and shadows of an uniparametric family of spherically symmetric
geometries interpolating between the Schwarzschild solution, a regular black hole, and a …

Simpson-Visser (SV) spacetimes are the simplest globally regular modifications of the
Schwarzschild, Reissner-Nordsröm and other black hole solutions of general relativity. They …

We model the supermassive dark object M 8 7* as a Schwarzschild lens and study the
variations in tangential, radial, and total (the product of tangential and radial) magnifications …

The silhouette of a black hole having a critical curve (an unstable bound photon orbit) when
illuminated by an optically thin accretion disk whose emission is confined to the equatorial …

Simpson and Visser recently proposed a phenomenological way to avoid some kinds of
space-time singularities by replacing a parameter whose zero value corresponds to a …

We investigate retrolensing by two photon spheres in a novel black-bounce spacetime
suggested by Lobo et al. which can correspond to a Schwarzschild black hole, a regular …

Ultracompact objects (UCOs) are horizonless compact objects that present light rings (LRs):
circular photon orbits. As a result, they could be black hole mimickers. Some years ago …

Black bounces are spacetimes that can describe, depending on certain parameters, black
holes or wormholes. In this work, we use a method to obtain the matter content that …

The so-called black-bounce mechanism of singularity suppression, proposed by Simpson
and Visser, consists of replacing the spherical radius r in the metric tensor with r 2+ a 2, a …