Abstract
It is commonly believed that the ringdown signal from a binary coalescence provides a conclusive proof for the formation of an event horizon after the merger. This expectation is based on the assumption that the ringdown waveform at intermediate times is dominated by the quasinormal modes of the final object. We point out that this assumption should be taken with great care, and that very compact objects with a light ring will display a similar ringdown stage, even when their quasinormal-mode spectrum is completely different from that of a black hole. In other words, universal ringdown waveforms indicate the presence of light rings, rather than of horizons. Only precision observations of the late-time ringdown signal, where the differences in the quasinormal-mode spectrum eventually show up, can be used to rule out exotic alternatives to black holes and to test quantum effects at the horizon scale.
- Received 25 February 2016
DOI:https://doi.org/10.1103/PhysRevLett.116.171101
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Erratum
Erratum: Is the Gravitational-Wave Ringdown a Probe of the Event Horizon? [Phys. Rev. Lett. 116, 171101 (2016)]
Vitor Cardoso, Edgardo Franzin, and Paolo Pani
Phys. Rev. Lett. 117, 089902 (2016)
Synopsis
Did Black Hole “Mimickers” Produce LIGO Signal?
Published 27 April 2016
Recently detected gravitational waves might not be a signature of black holes but of other massive objects that lack an event horizon.
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