Speaker
Description
According to the classical no-hair theorem, stationary black holes are uniquely characterized by their mass, charge, and angular momentum. In this talk, we derive the quantum-corrected black hole metric within the Barvinsky-Vilkovisky formalism and explore the effect of quantum hair in the metric, which is defined by the number of massless quantum fields. The quantum-corrected metric is obtained perturbatively around flat spacetime without assuming either the commutativity between the nonlocal operator and covariant derivatives or the nonlocal Gauss-Bonnet theorem, both of which are adopted in previous studies. Using this metric, we evaluate the deflection angle in the strong-field limit and compute the associated strong gravitational lensing observables, such as the angular separation and the relative magnification. We find that as the quantum hair increases, the photon sphere radius, the strong deflection angle, and the relative magnification all increase, whereas the angular separation decreases. As a result, we show that the quantum hair affects not only the black hole geometry but also its strong gravitational lensing effects.
