70 AIM, UMR 7158, CEA/DRF, CNRS, Université Paris Diderot, Irfu/Service d'Astrophysique,
Centre de Saclay, FR-91191 Gif-sur-Yvette, France

For ultra compact objects, light rings and fundamental photon orbits (FPOs) play a pivotal
role in the theoretical analysis of strong gravitational lensing effects, and of BH shadows in …

We consider a simple spherical model consisting of a Schwarzschild black hole of mass M
and a dark matter of mass ΔM around it. The general formula for the radius of black-hole …

In this paper, we construct an effective rotating loop quantum black hole (LQBH) solution,
starting from the spherical symmetric LQBH by applying the Newman-Janis algorithm …

The recent discovery of the novel four-dimensional static and spherically symmetric Gauss–
Bonnet black hole provides a promising bed to test Gauss–Bonnet gravity by using …

In this paper, we report on exact charged black hole solutions in symmergent gravity with
Maxwell field. Symmergent gravity induces the gravitational constant G, quadratic curvature …

In this paper, we study rotating black holes in symmergent gravity, and use deviations from
the Kerr black hole to constrain the parameters of the symmergent gravity. Symmergent …

In this paper, we first consider null geodesics of a class of charged, spherical and
asymptotically flat hairy black holes in an Einstein-Maxwell-scalar theory with a nonminimal …

We study the shadow cast or silhouette generated by a Kerr-Newman-Kasuya (KNK)
spacetime (rotating dyon black hole). It is shown that in addition to the angular momentum of …

We study the influence of the cosmic expansion on the size of the shadow of a spinning
black hole observed by a comoving observer. We first consider that the expansion is driven …