Ergoregion instability of ultra-compact astrophysical objects
Abstract
Most of the properties of black holes can be mimicked by horizonless compact objects such as gravastars and boson stars. We show that these ultra-compact objects develop a strong ergoregion instability when rapidly spinning. Instability timescales can be of the order of 0.1 seconds to 1 week for objects with mass M=1-10^6 solar masses and angular momentum J> 0.4 M^2. This provides a strong indication that ultra-compact objects with large rotation are black holes. Explosive events due to ergoregion instability have a well-defined gravitational-wave signature. These events could be detected by next-generation gravitational-wave detectors such as Advanced LIGO or LISA.
Cite
@article{arxiv.0709.0532,
title = {Ergoregion instability of ultra-compact astrophysical objects},
author = {Vitor Cardoso and Paolo Pani and Mariano Cadoni and Marco Cavaglia},
journal= {arXiv preprint arXiv:0709.0532},
year = {2008}
}
Comments
14 pages, 8 Figures, 6 Tables. RevTeX4. v2: Shortened version, published on PRD, focused on gravastars and boson stars. Sections on wormholes and superspinars will appear elsewhere