Emissions of photons near the horizons of Kerr-Sen black holes

Abstract

We investigate the escape probabilities of the photons near the horizon of the Kerr-Sen black hole. We find that the escape probabilities of the photons are nonzero in the event horizon limit of the extreme Kerr-Sen black hole if the light sources are near the equator. We show that the escape probability of a photon increases with the radial position of the light source. It is also uncovered that the escape probability decreases if the light source with constant radius moves from the equatorial plane to the pole. Besides, we discover that the escape probability of a photon in the Carter frame is always greater than the one in the locally non-rotating frame, except on the pole, where they are equal.

12 pages, 15 captioned figures, Sec. IV added

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Cited by in corpus (7)

• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Slice-reducible conformal Killing tensors, photon surfaces and shadows
• Complete classification of photon escape in the Kerr black hole spacetime
• Escape probability of particle from Kerr-Sen black hole
• Photon emissions from near-horizon extremal and near-extremal Kerr equatorial emitters
• Observability of Zero-angular-momentum Sources Near Kerr Black Holes
• Photon escape in the extremal Kerr black hole spacetime