Bosenova Collapse of Axion Cloud around a Rotating Black Hole
Abstract
Motivated by possible existence of stringy axions with ultralight mass, we study the behavior of an axion field around a rapidly rotating black hole (BH) obeying the sineGordon equation by numerical simulations. Due to superradiant instability, the axion field extracts the rotational energy of the BH and the nonlinear selfinteraction becomes important as the field grows larger. We present clear numerical evidences that the nonlinear effect leads to a collapse of the axion cloud and a subsequent explosive phenomena, which is analogous to the ``bosenova'' observed in experiments of BoseEinstein condensate. The criterion for the onset of the bosenova collapse is given. We also discuss the reason why the bosenova happens by constructing an effective theory of a wavepacket model under the nonrelativistic approximation.
 Publication:

Progress of Theoretical Physics
 Pub Date:
 July 2012
 DOI:
 10.1143/PTP.128.153
 arXiv:
 arXiv:1203.5070
 Bibcode:
 2012PThPh.128..153Y
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Extragalactic Astrophysics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory;
 83C57
 EPrint:
 38 pages, 18 figures