Strong gravitational lensing in a rotating Kaluza-Klein black hole with squashed horizons

Abstract

Abstract:We have investigated the strong gravitational lensing in a rotating squashed Kaluza-Klein (KK) black hole spacetime. Our result show that the strong gravitational lensings in the rotating squashed KK black hole spacetime have some distinct behaviors from those in the backgrounds of the four-dimensional Kerr black hole and of the squashed KK Gödel black hole. In the rotating squashed KK black hole spacetime, the marginally circular photon radius ρ ps , the coefficientā,b, the deflection angle α(θ) in the φ direction and the corresponding observational variables are independent of whether the photon goes with or against the rotation of the background, which is different with those in the usual four-dimensional Kerr black hole spacetime. Moreover, we also find that with the increase of the scale of extra dimension ρ 0 , the marginally circular photon radius ρ ps and the angular position of the relativistic images θ ∞ first decreases and then increases in the rotating squashed KK black hole for fixed rotation parameter b, but in the squashed KK Gödel black hole they increase for the smaller global rotation parameter j and decrease for the larger one. In the extremely squashed case ρ 0 = 0, the coefficientā in the rotating squashed KK black hole increases monotonously with the rotation parameter, but in the squashed KK Gödel black hole it is a constant and independent of the global rotation of the Gödel Universe. These information could help us to understand further the effects of the rotation parameter and the scale of extra dimension on the strong gravitational lensing in the black hole spacetimes.

Equatorial gravitational lensing by accelerating and rotating black hole with NUT parameter

“…and numerically studied equatorial as well as quasi-equatorial lensing of Kerr BH pierced by a cosmic string and Kerr-Taub-NUT BH. Ji et al (2014) investigated strong field lensing in a rotating squashed Kaluza-Klein BH and provided a comparison from four-dimensional Kerr and squashed Kaluza-Klein Gödel BH.…”

Strong gravitational lensing for photons coupled to Weyl tensor in a regular phantom black hole

“…These relativistic images carry the information about the source stars and gravitational lens, and they could provide the profound verification of alternative theories of gravity [4][5][6][7][8][9][10][11][12][13][14]. Thus, strong gravitational lensing is regarded as a powerful indicator of the physical nature of the central celestial object, and has been studied extensively in various theories of gravity [15][16][17][18][19][20][21][22][23][24] in recent years.…”

Revisiting the ADT mass of the five-dimensional rotating black holes with squashed horizons

“…[11][12][13][14][15][16][17][18][19][20][21][22]. As a prominent one of them, these black holes have provided opportunities to test several approaches on conserved quantities for various gravity theories, such as the Komar integral, the ADM formalism, the counterterm subtraction method, the (off-shell generalised) Abbott-DeserTekin (ADT) formulation and so on [2][3][4]8,[23][24][25][26][27][28][29][30][31].…”