Modified general relativity as a model for quantum gravitational collapse

Understand

We study a class of Hamiltonian deformations of the massless Einstein-Klein-Gordon system in spherical symmetry for which the Dirac constraint algebra closes.

• The system may be regarded as providing effective equations for quantum gravitational collapse.
• Guided by the observation that scalar field fluxes do not follow metric null directions due to the deformation, we find that the equations take a simple form in characteristic coordinates.
• We analyse these equations by a unique combination of numerical methods and find that Choptuik's mass scaling law is modified by a mass gap as well as jagged oscillations.