Sergio Dain

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I describe the construction of initial data for the Einstein vacuum equations that can represent a collision of two black holes. I stress in the main physical ideas. The physical system we want to describe is a binary system of two black holes. It is expected that lot of such systems exist in the universe. Moreover, these systems are expected to have the(More)
The notion of center of mass for an isolated system has been previously encoded in the definition of the so called nice sections. In this article we present a generalization of the proof of existence of solutions to the linearized equation for nice sections, and formalize a local existence proof of nice sections relaxing the radiation condition. We report(More)
In this essay I first discuss the physical relevance of the inequality m ≥ |J| for axially symmetric (non-stationary) black holes, where m is the mass and J the angular momentum of the spacetime. Then, I present a proof of this inequality for the case of one spinning black hole. The proof involves a remarkable characterization of the extreme Kerr black hole(More)