Showing papers by "José Natário published in 2008"
Journal Article•
TL;DR: In this paper, the authors match collapsing inhomogeneous as well as spatially homogeneous but anisotropic spacetimes to vacuum static exteriors with a negative cosmological constant and planar or hyperbolic symmetry.
Abstract: We match collapsing inhomogeneous as well as spatially homogeneous but anisotropic spacetimes to vacuum static exteriors with a negative cosmological constant and planar or hyperbolic symmetry. The collapsing interiors include the inhomogeneous solutions of Szekeres and of Barnes, which in turn include the Lemâitre-Tolman and the McVittie solutions. The collapse can result in toroidal or higher genus asymptotically AdS black holes.
12 citations
TL;DR: In this article, an idealized model of gravitational collapse is presented, describing a collapsing rotating cylindrical shell of null dust in flat space, with the metric of a spinning cosmic string as the exterior.
Abstract: We present an idealized model of gravitational collapse, describing a collapsing rotating cylindrical shell of null dust in flat space, with the metric of a spinning cosmic string as the exterior. We find that the shell bounces before closed timelike curves can be formed. Our results also suggest slightly different definitions for the mass and angular momentum of the string.
7 citations
TL;DR: In this article, the tangent Euler top in General Relativity was defined through a constrained Lagrangian on the orthonormal frame bundle and the corresponding motions were studied to various degrees of approximation, the lowest of which was shown to yield the Mathisson-Papapetrou equations.
Abstract: We define the tangent Euler top in General Relativity through a constrained Lagrangian on the orthonormal frame bundle. The corresponding motions are studied to various degrees of approximation, the lowest of which is shown to yield the Mathisson-Papapetrou equations.
5 citations
TL;DR: In this article, a coordinate system for the Kerr solution was proposed based on the zero angular momentum observers dropped from infinity, which generalizes the Painleve-Gullstrand coordinate systems for the Schwarzschild solution.
Abstract: We construct a coordinate system for the Kerr solution, based on the zero angular momentum observers dropped from infinity, which generalizes the Painleve-Gullstrand coordinate system for the Schwarzschild solution. The Kerr metric can then be interpreted as describing space flowing on a (curved) Riemannian 3-manifold. The stationary limit arises as the set of points on this manifold where the speed of the flow equals the speed of light, and the horizons as the set of points where the radial speed equals the speed of light. A deeper analysis of what is meant by the flow of space reveals that the acceleration of free-falling objects is generally not in the direction of this flow. Finally, we compare the new coordinate system with the closely related Doran coordinate system.
2 citations
TL;DR: In this paper, the authors summarize some of their recent results about the matching of collapsing inhomogeneous dust-filled spacetimes to vacuum static exteriors with a negative cosmological constant in planar or hyperbolic symmetry.
Abstract: In this contribution we summarize some of our recent results about
the matching of collapsing inhomogeneous dust-filled spacetimes to
vacuum static exteriors with a negative cosmological constant in
planar or hyperbolic symmetry. This models gravitational collapse to
toroidal or higher genus asymptotically AdS black holes.