paper

Exotic Compact Objects and the Fate of the Light-Ring Instability

arXiv:2207.13713 · doi:10.1103/PhysRevLett.130.061401

Abstract

Ultracompact objects with light-rings (LRs) but without an event horizon could mimic black holes (BHs) in their strong gravity phenomenology. But are such objects dynamically viable? Stationary and axisymmetric ultracompact objects that can form from smooth, quasi-Minkowski initial data must have at least one stable LR, which has been argued to trigger a spacetime instability; but its development and fate have been unknown. Using fully non-linear numerical evolutions of ultracompact bosonic stars free of any other known instabilities and introducing a novel adiabatic effective potential technique, we confirm the LRs triggered instability, identifying two possible fates: migration to non-ultracompact configurations or collapse to BHs. In concrete examples we show that typical migration/collapse time scales are not larger than light-crossing times, unless the stable LR potential well is very shallow. Our results show that the LR instability is effective in destroying horizonless ultracompact objects that could be plausible BH imitators.

arXiv comment5 pages + Appendices; Videos can be found in this URL http://gravitation.web.ua.pt/node/3889; v2. Title changed per request of journal. Published in Physical Review Letters as Editor's Suggestion and Featured in Physics

References in corpus (38)

Cited by in corpus (54)