Dr. Rogério A. Capobianco 

Black holes are among the most fascinating objects in our universe. These objects are typically studied as isolated objects. Still, in more realistic scenarios, black holes often exist in much more complex environments, like surrounded by accreting matter, in binary systems, or even immersed in external gravitational and electromagnetic fields. This project explores how external factors influence the behaviour of black holes and the motion of particles around them. We focus on recently discovered solutions of Einstein’s field equations, which combine rotation and electromagnetic fields. One of them also includes the cosmological constant, while the other represents a black hole immersed in an electromagnetized-rotating background. We

focus on the description of particle motion in these two solutions. The study of particle motions is keen to understand the geometrical properties of a spacetime, such as the curvature, horizon geometry, and the shape of the black hole shadow. These structures are essential to interpreting the current and future observations and for testing general relativity in the strong field regime.