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arXiv · 1611.05077

Evolving black holes from conformal transformations of static solutions

Marina M. C. Mello·Alan Maciel·Vilson T. Zanchin
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Abstract

A class of nonstationary spacetimes is obtained by means of a conformal transformation of the Schwarzschild metric, where the conformal factor $a(t)$ is an arbitrary function of the time coordinate only. We investigate several situations including some where the final state is a central object with constant mass. The metric is such that there is an initial big-bang type singularity and the final state depends on the chosen conformal factor. The Misner-Sharp mass is computed and a localized central object may be identified. The trapping horizons, geodesic and causal structure of the resulting spacetimes are investigated in detail. When $a(t)$ asymptotes to a constant in a short enough time scale, the spacetime presents an event horizon and its analytical extension reveals black-hole or white-hole regions. On the other hand, when $a(t)$ is unbounded from above as in cosmological models, the spacetime presents no event horizons and may present null singularities in the future. The energy-momentum content and other properties of the respective spacetimes are also investigated.

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Marina M. C. Mello, Alan Maciel, Vilson T. Zanchin. 2017-05-04. Evolving black holes from conformal transformations of static solutions. https://doi.org/10.1103/physrevd.95.084031

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