Light's bending angle in the equatorial plane of a Kerr black hole
- Department of Physics and Astronomy, State University of New York at Geneseo, 1 College Circle, Geneseo, New York 14454 (United States)
We present here a detailed derivation of an explicit spin-dependent expression for the bending angle of light as it traverses in the equatorial plane of a spinning black hole. We show that the deflection produced in the presence of the black hole angular momentum explicitly depends on whether the motion of the light ray is in the direction, or opposite to the spin. Compared to the zero-spin Schwarzschild case, the bending angle is greater for direct orbits, and smaller for retrograde orbits, confirming our physical intuition about the loss of left-right symmetry from a lensing perspective. In addition, we show that for higher spins, the effect is more pronounced resulting in tighter winding of direct orbits with respect to the axis of rotation, and a higher degree of unwinding of retrograde orbits. A direct consequence of this effect is a shift in image positions in strong gravitational lensing.
- OSTI ID:
- 21313615
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 80, Issue 12; Other Information: DOI: 10.1103/PhysRevD.80.124023; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Analytical Kerr black hole lensing in the weak deflection limit
Self-force on a scalar charge in Kerr spacetime: Circular equatorial orbits