RUDN astrophysicists have suggested an approach to simplify calculations of observable effects in the vicinity of black holes to which the mathematical apparatus of Einstein’s classic relativity theory does not apply. The results of the work were published in Physical Review D. According to the theory of general relativity, the movement of any massive body causes the occurrence of space-time ripples called gravitational waves. They were first registered in 2015. Gravitational waves are echoes of the merging of massive gravitational objects such as black holes—areas of space-time where gravity is so strong that not even light can escape.