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arXiv · 1102.0086

Strong gravitational lensing in a squashed Kaluza-Klein Gödel black hole

Songbai Chen·Yue Liu·Jiliang Jing
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Abstract

We investigate the strong gravitational lensing in a squashed Kaluza-Klein black hole immersed in the Gödel universe with global rotation. Our result show that the strong gravitational lensing in the squashed Kaluza-Klein Gödel black hole spacetime has some distinct behaviors from that in the Kerr case. In the squashed Kaluza-Klein Gödel black hole spacetime, the photon sphere radius, the minimum impact parameter, the coefficient $\bar{a}$, $\bar{b}$ and the deflection angle $α(θ)$ in the $ϕ$ direction are independent of whether the photon goes with or against the global rotation of the Gödel Universe. While in the Kerr black hole, the values of these quantities for the prograde photons are different from those for the retrograde photons. Moreover, the coefficient of $\bar{b}$ increases with $j$ in the squashed Kaluza-Klein Gödel black hole, but decreases with $a$ in the Kerr case. We also probe the influence of the squashed effect on the strong gravitational lensing in this black hole and find that in the extremely squashed case $ρ_0=0$, the coefficient $\bar{a}$ is a constant 1 and is independent of the global rotation of the Gödel Universe. Furthermore, we assume that the gravitational field of the supermassive central object of the Galaxy can be described by this metric and estimate the numerical values of the coefficients and the main observables in the strong gravitational lensing.

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Songbai Chen, Yue Liu, Jiliang Jing. 2011-05-26. Strong gravitational lensing in a squashed Kaluza-Klein Gödel black hole. https://doi.org/10.1103/physrevd.83.124019

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