8 papers
Gravitational null rays: Covariant Quantization and the Dressing Time
Laurent Freidel, Josh Kirklin
We quantize the degrees of freedom on a gravitational null ray segment in a fully gauge-invariant manner by using the dressing time as a quantum reference frame (QRF). Our work goe…
Localization and anomalous reference frames in gravity
Laurent Freidel, Josh Kirklin
In this work, we study the classical phase space for the gravitational degrees of freedom along a null ray. We construct gauge-invariant observables localized on a null ray segment…
Fighting non-locality with non-locality: microcausality and boundary conditions in QED
Philipp A. Hoehn, Josh Kirklin
In gauge theories, globally charged observables necessarily depend non-locally on the kinematical fields, with this dependence extending to the asymptotic boundary of spacetime. De…
Generalised second law beyond the semiclassical regime
Josh Kirklin
We prove that the generalised second law (GSL), with an appropriate modification, holds in perturbative gravity to all orders beyond the semiclassical limit and without a UV cutoff…
Crossed products and quantum reference frames: on the observer-dependence of gravitational entropy
Julian De Vuyst, Stefan Eccles, Philipp A. Hoehn +1
A significant step towards a rigorous understanding of perturbative gravitational entropy was recently achieved by a series of works showing that a proper accounting of gauge invar…
Linearization (in)stabilities and crossed products
Julian De Vuyst, Stefan Eccles, Philipp A. Hoehn +1
Modular crossed product algebras have recently assumed an important role in perturbative quantum gravity as they lead to an intrinsic regularization of entanglement entropies by in…