Um estudo do desvio da luz no formalismo de campo forte

Abstract

In this master thesis, we work out light deflection using the strong field approach and apply the results in the study of gravitational lensing. This formalism becomes useful when the light gets close to a photon sphere, where null geodesics trace circular orbits. In this limit, the impact parameter of the photon approaches the critical impact parameter, and if it is less than that the photon falls into the event horizon. We start assuming a static, spherically symmetric and asymptotically flat metric and then we apply this formalism to the Schwarzschild, Reissner-Nordström and black-bounce metrics. In the strong field limit, the integral for the light deflection diverges, so that we have to extract the divergent term and express the result in terms of some parameters. Ultimately, we define observables in the context of gravitational lensing with the purpose of distinguishing between those metrics from future experimental data.