IA/U.Lisboa Seminar - The Critical Collapse of Gravitational Waves - 12 março 2018

Initial data for a massless scalar field minimally coupled to gravity that is sufficiently weak will eventually disperse to leave behind flat space. Strong data will rather collapse to form a black hole. Breakthrough numerical work by Choptuik showed that a remarkable phenomenology occurs in the neighborhood of the solution that lies between these two cases. Despite significant progress, an open problem remains the equivalent situation in vacuum. I will discuss the progress and difficulties in this problem.