Black Holes and Covariance in Effective Quantum Gravity

This work addresses the longstanding issue of general covariance in spherically symmetric gravity, arising when canonical quantum gravity leads to a semiclassical model described by an effective Hamiltonian constraint. Applying the minimal requirements proposed to ensure general covariance, we derive the equations for the effective Hamiltonian constraint with the aid of imposing demands on Dirac observables. The equations yield two candidates for effective Hamiltonian constraints dependent on a quantum parameter. The resulting quantum modified black hole spacetimes are analyzed. Particularly, our models show improvement by casting off the known limitations of previous works with similar results.