The Repulsive Effect of Covariant Effective Quantum Gravity

In General Relativity, gravity around a black hole is universally regarded as an attractive force. However, quantum effects may significantly alter this classical picture and thus affect the dynamics of test particles. In this work, we investigate geodesic motion in a recently proposed covariant effective quantum black hole model, the ZLMY type I model in \href{https://journals.aps.org/prd/abstract/10.1103/PhysRevD.111.L081504}{[Phys.Rev.D 111 (2025) 8, L081504]}. Our analytical study reveals that, at the Planck scale, gravity can exhibit a repulsive character, most notably in trajectories involving turning points. These findings suggest that quantum corrections could fundamentally modify our conventional understanding of gravitational interactions in certain regimes.