Gravitational collapse of gravitational waves in 3D numerical relativity -art. no. 041501

We demonstrate that evolutions of three-dimensional, strongly non-linear gr avitational waves can be followed in numerical relativity, hence allowing m any interesting studies of both fundamental and observational consequences. We study the evolution of time-symmetric, axisymmetric and non-axisymmetri c Brill waves, including waves so strong that they collapse to form black h oles under their own self-gravity. An estimate for the critical amplitude f or black hole formation in a particular interpolating family of initial dat a is obtained. The gravitational waves emitted in the black hole formation process are compared to those emitted in the head-on collision of two Misne r black holes.