Strong Gravitational Lensing by Compact Object without Cauchy Horizons in Effective Quantum Gravity

Abstract

In this work, we theoretically investigate strong gravitational lensing effects and evaluate various lensing observables of a static, spherically symmetric solution in the context of effective quantum gravity (EQG). Among the three types of solutions proposed in EQG backgrounds, this is the third type without having Cauchy horizons. This solution gives rise to black hole as well as horizonless wormhole solutions depending on the range of values of the parameters of the theory. Based on the data from SgrA* and M87* observations, possible bounds on the parameter are obtained. It is found that the horizonless wormhole solution is ruled out by SgrA* observations, but is allowed by M87* observations. We analyze and provide estimates of the lensing observables, some of which can potentially be detected by observational tools.