23 citations · 24 across the 6 of their papers we have counts for
6 papers
The Phase Space of Gravity on Null Hypersurfaces
Luca Ciambelli, Laurent Freidel, Robert G. Leigh
We construct the bulk kinematical Poisson structure of general relativity on a caustic-free null segment, prior to imposing the Raychaudhuri and Damour constraints. We first show t…
The Problem of Time and its Quantum Resolution
Marc S. Klinger, Robert G. Leigh
In this essay, we argue that the problem of time should not be regarded as an issue to be resolved within the prevailing framework for studying quantum gravity, but rather as an in…
Relational Quantum Geometry
Shadi Ali Ahmad, Wissam Chemissany, Marc S. Klinger +1
A common feature of the extended phase space of gauge theory, the crossed product of quantum theory, and quantum reference frames (QRFs) is the adjoining of degrees of freedom foll…
Quantum Null Geometry and Gravity
Luca Ciambelli, Laurent Freidel, Robert G. Leigh
In this work, we demonstrate that quantizing gravity on a null hypersurface leads to the emergence of a CFT associated with each null ray. This result stems from the ultralocal nat…
Quantum Reference Frames from Top-Down Crossed Products
Shadi Ali Ahmad, Wissam Chemissany, Marc S. Klinger +1
All physical observations are made relative to a reference frame, which is a system in its own right. If the system of interest admits a group symmetry, the reference frame observi…
Crossed Products, Conditional Expectations and Constraint Quantization
Marc S. Klinger, Robert G. Leigh
Recent work has highlighted the importance of crossed products in correctly elucidating the operator algebraic approach to quantum field theories. In the gravitational context, the…