Self force on a scalar charge in Kerr spacetime: circular equatorial orbits
Warburton, Niels and Barack, Leor (2010) Self force on a scalar charge in Kerr spacetime: circular equatorial orbits. Physical Review D, 81, (8), 084039. (doi:10.1103/PhysRevD.81.084039).
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Description/Abstract
We present a calculation of the scalar field selfforce (SSF) acting on a scalarcharge particle in a strongfield orbit around a Kerr black hole. Our calculation specializes to circular and equatorial geodesic orbits. The analysis is an implementation of the standard modesum regularization scheme: We first calculate the multipole modes of the scalarfield perturbation using numerical integration in the frequency domain, and then apply a certain regularization procedure to each of the modes. The dissipative piece of the SSF is found to be consistent with the flux of energy and angular momentum carried by the scalar waves through the event horizon and out to infinity. The conservative (radial) component of the SSF is calculated here for the first time. When the motion is retrograde this component is found to be repulsive (outward pointing, as in the Schwarzschild case) for any spin parameter a and (BoyerLindquist) orbital radius r0. However, for prograde orbits we find that the radial SSF becomes attractive (inward pointing) for r0 > rc(a), where rc is a critical adependent radius at which the radial SSF vanishes. The dominant conservative effect of the SSF in Schwarzschild spacetime is known to be of 3rd postNewtonian (PN) order (with a logarithmic running). Our numerical results suggest that the leadingorder PN correction due to the black hole's spin arises from spinorbit coupling at 3PN, which dominates the overall SSF effect at large r0. In PN language, the changeofsign of the radial SSF is attributed to an interplay between the spinorbit term ( ar04.5) and the "Schwarzschild" term ( r05logr0)
Item Type:  Article  

Digital Object Identifier (DOI):  doi:10.1103/PhysRevD.81.084039  
ISSNs:  15507998 (print) 10894918 (electronic) 

Subjects:  Q Science > QC Physics Q Science > QA Mathematics Q Science > QB Astronomy 

Divisions :  University Structure  Pre August 2011 > School of Mathematics > Applied Mathematics 

ePrint ID:  79819  
Accepted Date and Publication Date: 


Date Deposited:  22 Mar 2010  
Last Modified:  31 Mar 2016 13:16  
URI:  http://eprints.soton.ac.uk/id/eprint/79819 
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