Speaker
Matteo Bruno
(Centre de Physique Théorique (CPT))
Description
The physical projector (or rigging map in Refined Algebraic Quantization) is a powerful tool in the quantisation of constrained systems. In this talk, we argue that the physical projector alone —even without well-defined quantum constraint operators— is sufficient to define physical states and physical observables, within an framework alternative to the relational approach.
This viewpoint is motivated by the longstanding heuristic interpretation of the gravitational path integral as a projector onto the solutions of the Wheeler–DeWitt equation. We provide strong support for this idea by showing that spin-foam amplitudes always define a rigging map,
Author
Matteo Bruno
(Centre de Physique Théorique (CPT))