Null Geodesics and Gravitational Lensing in a Nonsingular Spacetime

Abstract EN

The null geodesics and gravitational lensing in a nonsingular spacetime are investigated.

According to the nature of the null geodesics, the spacetime is divided into several cases.

In the weak deflection limit, we find the influence of the nonsingularity parameter q on the positionsand magnifications of the images is negligible.

In the strong deflection limit, the coefficientsand observables for the gravitational lensing in a nonsingular black hole background and a weaklynonsingular spacetime are obtained.

Comparing these results, we find that, in a weakly nonsingularspacetime, the relativistic images have smaller angular position and relative magnificationbut larger angular separation than those of a nonsingular black hole.

These results might offer away to probe the spacetime nonsingularity parameter and put a bound on it by the astronomicalinstruments in the near future.