Deflection angle and lensing signature of covariant f(T) gravity

We calculate the deflection angle, as well as the positions and magnifications of the lensed images, in the case of covariant f (T) gravity. We first extract the spherically symmetric solutions for both the pure-tetrad and the covariant formulation of the theory, since considering spherical solutions the extension to the latter is crucial, in order for the results not to suffer from frame-dependent artifacts. Applying the weak-field, perturbative approximation we extract the deviations of the solutions comparing to General Relativity. Furthermore, we calculate the deflection angle and then the differences of the positions and magnifications in the lensing framework. This effect of consistent f (T) gravity on the lensing features can serve as an observable signature in the realistic cases where f (T) is expected to deviate only slightly from General Relativity, since lensing scales in general are not restricted as in the case of Solar System data, and therefore deviations from General Relativity could be observed more easily.

Automated summary

In the case of covariant f(T) gravity, calculations were made for the deflection angle, positions, and magnifications of lensed images. Deviations from General Relativity were extracted by considering spherical solutions and applying weak-field, perturbative approximation. This study suggests that the effects of consistent f(T) gravity on lensing features can serve as observable signatures in practical scenarios.