Motion of particles and gravitational lensing around the (2+1)-dimensional BTZ black hole in Gauss–Bonnet gravity

Abstract We study the motion of test particles and photons in vicinity (2+1)-dimensional Gauss–Bonnet (GB) BTZ black hole. find that presence coupling constant serves as an attractive gravitational charge, shifting innermost stable circular orbits outward with respect to one for this theory four dimensions. Further, we consider lensing, GB gravity (2+1) dimensions show parameter causes bending angle first increase inverse closest approach distance, $$u_0$$ u0 , reaching a peak value specific $$u_0^*$$ xmlns:mml="http://www.w3.org/1998/Math/MathML">u0∗ then decreasing zero. also decreases angle, absolute negative cosmological produces opposite effect on angle.