https://doi.org/10.1140/epjc/s10052-021-09617-4
Regular Article - Theoretical Physics
Motion of particles and gravitational lensing around the (2+1)-dimensional BTZ black hole in Gauss–Bonnet gravity
1
Department of Physics, Center for Field Theory and Particle Physics, Fudan University, 200438, Shanghai, China
2
Akfa University, Kichik Halqa Yuli Street 17, 100095, Tashkent, Uzbekistan
3
Ulugh Beg Astronomical Institute, Astronomy St 33, 100052, Tashkent, Uzbekistan
4
Institute for Theoretical Physics and Cosmology, Zheijiang University of Technology, 310023, Hangzhou, China
5
National University of Uzbekistan, 100174, Tashkent, Uzbekistan
6
Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, Kori Niyoziy 39, 100000, Tashkent, Uzbekistan
7
School of Electrical Engineering and Computer Science, National University of Sciences and Technology, H-12, Islamabad, Pakistan
8
Institute of Nuclear Physics, Ulugbek 1, 100214, Tashkent, Uzbekistan
9
Shanghai Astronomical Observatory, 80 Nandan Road, 200030, Shanghai, People’s Republic of China
10
Power Engineering Faculty, Tashkent State Technical University, 100095, Tashkent, Uzbekistan
Received:
15
December
2020
Accepted:
6
September
2021
Published online:
25
September
2021
We study the motion of test particles and photons in the vicinity of the (2+1)-dimensional Gauss–Bonnet (GB) BTZ black hole. We find that the presence of the coupling constant serves as an attractive gravitational charge, shifting the innermost stable circular orbits outward with respect to the one for this theory in four dimensions. Further, we consider the gravitational lensing, to test the GB gravity in (2+1) dimensions and show that the presence of the GB parameter causes the bending angle to first increase with the increase in the inverse of the closest approach distance, 
, reaching a peak value for a specific 
, and then decreasing to zero. We also show that the increase in the value of the GB parameter decreases the bending angle, and the increase in the absolute value of the negative cosmological constant produces an opposite effect on this angle.
© The Author(s) 2021
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