The recent observation of gravitational waves confirms one of the most interesting predictions in general relativity: the black holes. Because the gravitational waves detected by LIGO fit very well within general relativity as a phenomenon produced by two colliding black holes. Then the reality of black holes seems almost undoubted today. However, a stronger proof on the reality of black holes would be indicated by the observation of the event horizon, which is what defines it. In this article, it is indicated that only the event horizon defines a black hole. There is no mention to the singularity in its definition. Thus, it will be shown that black holes without a singularity are possible. Such black holes are called regular black holes.
Black holes; Gravitational Waves; General Relativity; Singularity