https://doi.org/10.1140/epjc/s10052-018-6466-9
Regular Article - Theoretical Physics
A new asymptotical flat and spherically symmetric solution in the generalized Einstein–Cartan–Kibble–Sciama gravity and gravitational lensing
1
Institute of Physics and Department of Physics, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
2
Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
3
Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
4
Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou, 225009, China
* e-mail: csb3752@hunnu.edu.cn
Received:
14
May
2018
Accepted:
18
November
2018
Published online:
27
November
2018
We firstly present a new asymptotical flat and spherically symmetric solution in the generalized Einstein–Cartan–Kibble–Sciama theory of gravity and then investigate the propagation of photon in this background. This solution possesses three independent parameters which affect sharply photon sphere, deflection angle of light ray and gravitational lensing. Since the condition of existence of horizons is not inconsistent with that of photon sphere, there exists a special case where there is horizon but no photon sphere in this spacetime. Especially, we find that in this special case, the deflection angle of a light ray near the event horizon tends to a finite value rather than diverges, which is not explored in other spacetimes. We also study the strong gravitational lensing in this spacetime with the photon sphere and then probe how the spacetime parameters affect the coefficients in the strong field limit.
© The Author(s), 2018