1993/07/07 by Adam D. Helfer, Adam D Helfer · 1 citation
Physics and Astronomy · #Angular momentum #Angular momentum coupling #Angular momentum of light #Angular momentum operator #Anomaly (physics) #Group (periodic table) #Pulsars and Gravitational Waves Research #Quadrupole #Quantum Chromodynamics and Particle Interactions #Quantum and Classical Electrodynamics #Specific relative angular momentum #Total angular momentum quantum number #gr-qc
paper · pdf · doi:10.1088/0264-9381/11/3/023
published in Classical and Quantum Gravity 11(3), 733-755 (IOP Publishing) · 33 pages
arxiv created 1993/07/07 · openalex publication_date 1994/03/01 · arxiv updated 2010/04/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We compute the motions of null infinity to which the components of the angular momentum of the gravitational field, as defined by Penrose, are conjugate. We find that the boosts are supplemented by anomalous translations. If is the skew bivector determining the component of the angular momentum in question, the anomaly is proportional to , where is a unit vector in the direction of the Bondi--Sachs momentum and is the quadrupole moment of the shear of the cut at which the angular momentum is evaluated. This effect persists in the weak field limit. This surprising result is a general consequence of the requirement that angular momentum be super-translation--invariant in a quiescent regime, and not some essentially twistorial peculiarity.