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 …

Recently, the image of a Schwarzschild black hole with an accretion disk has been revisited,
and it showed that the “photon ring,” defined as highly bent light rays that intersect the disk …

A bstract For a static and spherically symmetric black hole, a photon sphere is composed of
circular null geodesics of fixed radius, and plays an important role in observing the black …

Recently, asymptotically flat black holes with multiple photon spheres have been discovered
and found to produce distinctive observational signatures. In this paper, we focus on …

A bstract In this paper, we construct scalarized rotating black holes within the framework of
Einstein-Maxwell-scalar models. These models incorporate non-minimal couplings that can …

We study the method of extended gravitational decoupling in obtaining static black hole
solutions satisfying Einstein's equations with a tensor vacuum. The source has quite generic …

We study gravitational lensing of light by hairy black holes, which, in a certain parameter
regime, can possess two photon spheres of different size outside the event horizon. In …

In the framework of a simple gravitational theory that contains a scalar field minimally
coupled to gravity, we investigate the emergence of analytic black-hole solutions with …

Photon spheres play a pivotal role in the imaging of luminous objects near black holes. In
this paper, we examine observational appearances of a star freely falling in hairy black …

We investigate the dynamical transition processes of an Einstein-Maxwell-scalar
gravitational system between two local ground states and an excited state in the anti–de …