Gravitational lensing in black-bounce spacetimes

Weak deflection angle of black-bounce traversable wormholes usingGauss–Bonnet theorem in the dark matter medium

“…Note that it is in well agreement with the [57] in leading order terms.…”

“…In this paper, our main motivation is to explore weak deflection angle of black-bounce traversable wormholes [56,57] using the GBT and then extend our motivation of this research is to shed light on the effect of dark matter medium on the weak deflection angle of black-bounce traversable wormhole using the GBT. Note that the refractive index of the medium is supposed that it is spatially nonuniform but one can consider that it is uniform at large distances [58][59][60][61][62][63][64].…”

Einstein and Møller Energy-Momentum Distributions for the Static Regular Simpson–Visser Space-Time

“…In the case a = 0 and m = 0, which corresponds to the Schwarzschild metric, the energy in the Møller prescription is equal to the ADM mass M. The obtained results for the Einstein energy E E and the Møller energy E M come to support the use of the Einstein and Møller prescriptions for the evaluation of the energy of a gravitational background, specifying that the positive energy regions can serve as a convergent gravitational lens, while the negative one can serve as a divergent gravitational lens [56]. In fact, the Simpson-Visser metric and its generalizations appear to be extremely advantageous for a deeper understanding of strong-field gravitational lensing of light reflected by a photon sphere of black holes and wormholes [55,[57][58][59]. Further, the small region of negativity in the expressions of the Einstein energy E E in the case a < 2m indicates some difficulty in the physically meaningful interpretation of the energy in certain regions of a specific space-time.…”

Gravitational lensing in the Simpson-Visser black-bounce spacetime in a strong deflection limit

“…Thus, its gravitational lensing in the strong deflection limit with K = 0 and N ≥ 2 will be very similar to the one in the Simpson-Visser geometry investigated in Refs. [69,71].…”

“…When the ADM mass is nonzero m = 0, the deflection angle is given by [69][70][71] Here and hereinafter, the upper (lower) sign is chosen for the positive (negative) impact parameter. The magnifications of the images are given by…”