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GR: Fachverband Gravitation und Relativitätstheorie

GR 1: Black Holes I

GR 1.3: Talk

Monday, March 11, 2024, 17:25–17:45, HBR 14: HS 2

Wave Optical imaging by point-source scattering for a KTNdS black hole — •Felix Willenborg^{1, 2}, Dennis Philipp^{1, 2}, and Claus Lämmerzahl^{1, 2} — ¹Zentrum für angewandte Raumfahrt und Mikrogravitation (ZARM), University of Bremen, 28359 Bremen, Germany — ²Gauss-Olbers Center, c/o ZARM, University of Bremen, 28359 Bremen, Germany

The Kerr-Taub-NUT-de Sitter (KTNdS) spacetime is an interesting model due to its special property of conical singularities and the so-called Misner string in the presence of a gravitomagnetic monopole, the NUT charge parameter l. Gravitational lensing maps have shown that these become apparent to an observer for light- and time-like geodesics. Furthermore, the background appears “twisted” depending on the value of l.

Instead of describing the observation with ray-optical methods, wave-optical images are another approach to the problem. Here we observe the scattering of a monochromatic point source to an observer at a larger distance from the black hole. We are interested in how the previous observations of the ray-optical approaches turn out at very low frequencies, and whether the same characteristic observations can be made since the wave-optical approach coincides with the ray-optical approach at high frequencies. We present results for Schwarzschild-de Sitter and Kerr-de Sitter black holes for very low frequencies in a wave-optical approach. Furthermore, we motivate the analysis towards Taub-NUT-de Sitter (TNdS) and Kerr-Taub-NUT-de Sitter black holes and discuss our current state.

Keywords: black hole; Kerr-Taub-NUT-de Sitter; KTNdS; wave optical image; scattering