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.
Brown-York charges at null boundaries
8 Pith papers cite this work. Polarity classification is still indexing.
abstract
The Brown-York stress tensor provides a means for defining quasilocal gravitational charges in subregions bounded by a timelike hypersurface. We consider the generalization of this stress tensor to null hypersurfaces. Such a stress tensor can be derived from the on-shell subregion action of general relativity associated with a Dirichlet variational principle, which fixes an induced Carroll structure on the null boundary. The formula for the mixed-index tensor $T{}^i{}_j$ takes a remarkably simple form that is manifestly independent of the choice of auxiliary null vector at the null surface, and we compare this expression to previous proposals for null Brown-York stress tensors. The stress tensor we obtain satisfies a covariant conservation equation with respect to any connection induced from a rigging vector at the hypersurface, as a result of the null constraint equations. For transformations that act covariantly on the boundary structures, the Brown-York charges coincide with canonical charges constructed from a version of the Wald-Zoupas procedure. For anomalous transformations, the charges differ by an intrinsic functional of the boundary geometry, which we explicity verify for a set of symmetries associated with finite null hypersurfaces. Applications of the null Brown-York stress tensor to symmetries of asymptotically flat spacetimes and celestial holography are discussed.
citation-role summary
citation-polarity summary
fields
hep-th 8roles
background 3polarities
background 3representative citing papers
A Carroll-covariant energy-momentum-news complex at future null infinity yields Ward identities that generalise the Bondi loss equations, with an anomalous Carroll boost.
A microscopic derivation of Carrollian fluid equations from a statistical mechanics of interacting instantonic branes, plus initial elements of Carrollian thermodynamics.
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
A semi-classical symplectic two-form is defined as the sum of the gravitational symplectic form and the Berry curvature of the quantum matter state; it is shown to be independent of the Cauchy slice and to satisfy a quantum generalization of the Hollands-Iyer-Wald identity.
Constructs Carrollian OPEs that govern short-distance behavior, extends representation theory for composites, and classifies 2-, 3-, and 4-point correlators/amplitudes under Carrollian symmetry.
A 3d sourced conformal Carrollian field theory is proposed to holographically capture 4d flat gravity kinematics, with Ward identities matching 2d celestial CFT after relating operators.
A review summarizing Carrollian symmetries, CCFT constructions, and applications in AFS holography, Carroll hydrodynamics, and condensed matter phenomena such as fractons and flat bands.
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.
-
The Energy-Momentum-News Complex near Future Null Infinity
A Carroll-covariant energy-momentum-news complex at future null infinity yields Ward identities that generalise the Bondi loss equations, with an anomalous Carroll boost.
-
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.
-
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
-
Covariant phase space and the semi-classical Einstein equation
A semi-classical symplectic two-form is defined as the sum of the gravitational symplectic form and the Berry curvature of the quantum matter state; it is shown to be independent of the Cauchy slice and to satisfy a quantum generalization of the Hollands-Iyer-Wald identity.
-
Operator Product Expansion in Carrollian CFT
Constructs Carrollian OPEs that govern short-distance behavior, extends representation theory for composites, and classifies 2-, 3-, and 4-point correlators/amplitudes under Carrollian symmetry.
-
Carrollian Perspective on Celestial Holography
A 3d sourced conformal Carrollian field theory is proposed to holographically capture 4d flat gravity kinematics, with Ward identities matching 2d celestial CFT after relating operators.
-
The Carrollian Kaleidoscope
A review summarizing Carrollian symmetries, CCFT constructions, and applications in AFS holography, Carroll hydrodynamics, and condensed matter phenomena such as fractons and flat bands.