Gravitational lensing effect of black holes in effective quantum gravity

Abstract: In the present work, we investigate the gravitational lensing effects of two quantum-modified black hole models recently proposed in effective quantum gravity. The light deflection angles are calculated for both the weak-field and strong-field limits. Furthermore, using the data for the supermassive black holes SgrA* and M87*, we calculate the lensing observables in the strong-field limit. We find that the quantum parameter plays a role analogous to the electric charge in weak gravitational lensing. In the strong-field limit, in contrast, the effects of the quantum parameter on the deflection angle, the angular separation, and the relative magnification are opposite to those of the electric charge, the scalar charge, and the quantum parameters in some gravity theories. The results indicate the crucial difference between the classical black holes and the two quantum-modified black hole models that depend on the quantum correction, making them a valuable tool for distinguishing these black hole models.