the study of rotating non-kerr black hole
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2012 年两岸粒子物理与宇宙学研讨会. The study of rotating non-Kerr black hole. Songbai Chen Hunan Normal University Chongqing, 2012. 5. Outline. Introduction Rotating non-Kerr black hole Thin disk around a rotating non-Kerr black hole Strong gravitational lensing by rotating non-Kerr black hole - PowerPoint PPT PresentationTRANSCRIPT
The study of rotating non-Kerr black hole
Songbai Chen
Hunan Normal University
Chongqing, 2012. 5
2012年两岸粒子物理与宇宙学研讨会
Outline
1. Introduction
2. Rotating non-Kerr black hole
3. Thin disk around a rotating non-Kerr black hole
4. Strong gravitational lensing by rotating non-Kerr black hole
5. Summary
1. Introduction
1 No-Hair Theorem
Parameters of BH : M, a, Q
General Relativity (GR)
Kerr metric: stationary, axisymmetric, asymptotically flat vacuum spacetime
an event horizon but no closed timelike curves outside of the horizon
a definite proof for is still lacking !
It predicts that all astrophysical black holes are Kerr black holes
Possible approaches: Gravitational-wave
Electromagnetic spectrum
Test to no hair theorem
The existence of black holes
Free parameters:
measure potential deviations from the Kerr metric
(1) no deviation
the compact object is indeed a Kerr black hole.
(2) a deviation is measured to be nonzero
a) GR: the object cannot be a black hole
b) The object is known to possess an event horizon,
The no-hair theorem would be falsified !
Suggestion
Several models with parametric deviations from the Kerr metric
(1) Ryan et al: compact objects with a general expansion in Geroch-Hansen multipoles Phys. Rev. D 52, 5707 (1995); Phys. Rev. D 56, 1845 (1997)
(2) Collins et al: Kerr-like metrics with perturbations in the form of Weyl sector bumps
Phys. Rev. D 69, 124022 (2004), Phys. Rev. D 81, 024030 (2010).
(3) Glampedakis et al: Kerr-like metric deviating from the Kerr metric by an independent quadrupole moment.
Class. Quantum Grav. 23, 4167 (2006).
(4) Gair : metric with the quadrupole as well as higher order moments.
Phys. Rev. D 77, 024035 (2008).
Problem:
(5) Sopuerta & Yunes: a slowly rotating black hole violating parity
Phys. Rev. D 80, 064006 (2009).
(6) Vigeland et al: parametric deviations from the Kerr metric by possessing four integrals of the motion
Phys. Rev. D 83, 104027 (2011)……
outside of the event horizonSingularities or closed timelike loops
an artificial cutoff: motion of particle far away the region with singularity or CTC
For rapidly spinning black holes,
the artificial cutoff is no longer possible since R_isco becomes comparable to R_H.
For moderately spinning black holes
2. Rotating non-Kerr black hole
T. Johannsen and D. Psaltis
The metric of the rotating non-Kerr black hole
Phys. Rev. D83 124015 (2011)
C.Bambi, L. Modesto, Phys. Lett. B 706:13-18 (2011)
Changqing Liu, Songbai Chen, Jiliang Jing, accepted by APJ
3. Thin disk around a rotating non-Kerr black hole
Songbai Chen, Jiliang Jing , Phys. Lett. B 711, 81-87 (2012)
D.N. Page, K.S. Thorne, Astrophys. J. 191 (1974) 499. K.S. Thorne, Astrophys. J. 191 (1974) 507
4. Strong gravitational lensing by rotating non-Kerr black hole
SO
Lens
5.Summary
1. Properties of the rotating non-Kerr black hole
2. Thin accrete disk around the rotating non-Kerr black
hole
3. Gravitational lensing by the rotating non-Kerr black
hole
Thank you!