2022/07/11 by Po-Ning Chen, Chen, Po-Ning, Daniel E Paraizo +9 · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Differential Geometry (math.DG) #FOS: Mathematics #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Theory (hep-th) #Mathematical Physics (math-ph) #Relativity and Gravitational Theory #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2207.04590
openalex publication_date 2022/07/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We introduce a notion of "cross-section continuity" as a criterion for the viability of definitions of angular momentum, J, at null infinity: If a sequence of cross-sections, \mathcal Cn, of null infinity converges uniformly to a cross-section \mathcal C, then the angular momentum, Jn, on \mathcal Cn should converge to the angular momentum, J, on \mathcal C. The Dray-Streubel (DS) definition of angular momentum automatically satisfies this criterion by virtue of the existence of a well defined flux associated with this definition. However, we show that the one-parameter modification of the DS definition proposed by Compere and Nichols (CN) -- which encompasses numerous other alternative definitions -- does not satisfy cross-section continuity. On the other hand, we prove that the Chen-Wang-Yau (CWY) definition does satisfy the cross-section continuity criterion.