Quantum self-gravitating collapsing matter in a quantum geometry

Understand

The problem of how space-time responds to gravitating quantum matter in full quantum gravity has been one of the main questions that any program of quantization of gravity should address.

• Here we analyze this issue by considering the quantization of a collapsing null shell coupled to spherically symmetric loop quantum gravity.
• We show that the constraint algebra of canonical gravity is Abelian both classically and when quantized using loop quantum gravity techniques.
• The Hamiltonian constraint is well defined and suitable Dirac observables characterizing the problem were identified at the quantum level.