Gravitational null rays are quantized in a diffeomorphism-covariant way using the gravitational dressing time as quantum reference frame, producing a Virasoro crossed-product algebra of gauge-invariant observables.
Null Raychaudhuri: canonical structure and the dressing time
7 Pith papers cite this work. Polarity classification is still indexing.
7
Pith papers citing it
abstract
We initiate a study of gravity focusing on generic null hypersurfaces, non-perturbatively in the Newton coupling. We present an off-shell account of the extended phase space of the theory, which includes the expected spin-2 data as well as spin-0, spin-1 and arbitrary matter degrees of freedom. We construct the charges and the corresponding kinematic Poisson brackets, employing a Beltrami parameterization of the spin-2 modes. We explicitly show that the constraint algebra closes, the details of which depend on the non-perturbative mixing between spin-0 and spin-2 modes. Finally we show that the spin zero sector encodes a notion of a clock, called dressing time, which is dynamical and conjugate to the constraint. It is well-known that the null Raychaudhuri equation describes how the geometric data of a null hypersurface evolve in null time in response to gravitational radiation and external matter. Our analysis leads to three complementary viewpoints on this equation. First, it can be understood as a Carrollian stress tensor conservation equation. Second, we construct spin-$0$, spin-$2$ and matter stress tensors that act as generators of null time reparametrizations for each sector. This leads to the perspective that the null Raychaudhuri equation can be understood as imposing that the sum of CFT-like stress tensors vanishes. Third, we solve the Raychaudhuri constraint non-perturbatively. The solution relates the dressing time to the spin-$2$ and matter boost charge operators. Finally we establish that the corner charge corresponding to the boost operator in the dressing time frame is monotonic. These results show that the notion of an observer can be thought of as emerging from the gravitational degrees of freedom themselves. We briefly mention that the construction offers new insights into focusing conjectures.
citation-role summary
background 4
citation-polarity summary
fields
hep-th 7roles
background 4polarities
background 4representative citing papers
An operator-algebraic quantization of the characteristic initial-value problem yields a candidate on-shell algebra for a gravitational subregion bounded by two null hypersurfaces.
A microscopic derivation of Carrollian fluid equations from a statistical mechanics of interacting instantonic branes, plus initial elements of Carrollian thermodynamics.
The noise spectrum an interferometer would see from quantum spacetime jitter is computed for vacuum, thermal, squeezed, and scalar-backreaction states; all are Planck-suppressed.
Constructs a phase space for gravitational degrees of freedom on null ray segments with commuting localized observables via edge modes and dressing time, then introduces an effective classical theory with Virasoro deformations to capture diffeomorphism anomalies and distinguish gauge, physical, and
Establishes a holographic link between bulk gravitational radiation and dissipative corrections plus entropy production in boundary fluids, then constructs Carrollian analogues and celestial observables in the flat limit.
Phase space of arbitrary null cut in Minkowski spacetime is symplectomorphic to infrared phase space of asymptotically flat gravity, mapping cut fluctuations to leading soft graviton mode and supertranslation Goldstone mode to cut size times null time offset.
citing papers explorer
-
Gravitational null rays: Covariant Quantization and the Dressing Time
Gravitational null rays are quantized in a diffeomorphism-covariant way using the gravitational dressing time as quantum reference frame, producing a Virasoro crossed-product algebra of gauge-invariant observables.
-
Quantization of Gravity on Null Hypersurfaces
An operator-algebraic quantization of the characteristic initial-value problem yields a candidate on-shell algebra for a gravitational subregion bounded by two null hypersurfaces.
-
Kinetic Theory of Carroll Hydrodynamics
A microscopic derivation of Carrollian fluid equations from a statistical mechanics of interacting instantonic branes, plus initial elements of Carrollian thermodynamics.
-
Geometric noise spectrum in interferometers
The noise spectrum an interferometer would see from quantum spacetime jitter is computed for vacuum, thermal, squeezed, and scalar-backreaction states; all are Planck-suppressed.
-
Localization and anomalous reference frames in gravity
Constructs a phase space for gravitational degrees of freedom on null ray segments with commuting localized observables via edge modes and dressing time, then introduces an effective classical theory with Virasoro deformations to capture diffeomorphism anomalies and distinguish gauge, physical, and
-
Radiation in Fluid/Gravity and the Flat Limit
Establishes a holographic link between bulk gravitational radiation and dissipative corrections plus entropy production in boundary fluids, then constructs Carrollian analogues and celestial observables in the flat limit.
-
Mapping the Infrared Phase Space of Gravity to Finite Subregions
Phase space of arbitrary null cut in Minkowski spacetime is symplectomorphic to infrared phase space of asymptotically flat gravity, mapping cut fluctuations to leading soft graviton mode and supertranslation Goldstone mode to cut size times null time offset.