Newman-Penrose-like exact and approximate conservation laws: a covariant and conformal formulation

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Schneider, Berend
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912461767049216
author Schneider, Berend
author_facet Schneider, Berend
contents Using a conformal extension of the Geroch-Held-Penrose (GHP) formalism I derive a manifestly covariant and conformal expression of Newman-Penrose (NP) constants, which are a set of conserved quantities associated to solutions to the wave equation on light cones in Minkowski space. The resulting expression generalizes to massless fields of arbitrary spin -- including the electromagnetic field, Weyl fermions, and the linearized Weyl tensor -- on conformally flat space-times. In some non-conformally flat space-times there may exist conserved charges on very special null hypersurfaces. Using the conformal GHP formalism I prove the existence of conserved Aretakis charges on extremal Killing horizons. In the absence of exact conservation laws it is still useful to extend the definition for NP constants to some asymptotically flat curved space-times, where the conservation laws become approximate conservation laws which rapidly approach exact conservation laws at null infinity. I derive explicit expressions for spherically symmetric space-times.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02237
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Newman-Penrose-like exact and approximate conservation laws: a covariant and conformal formulation
Schneider, Berend
General Relativity and Quantum Cosmology
Mathematical Physics
Using a conformal extension of the Geroch-Held-Penrose (GHP) formalism I derive a manifestly covariant and conformal expression of Newman-Penrose (NP) constants, which are a set of conserved quantities associated to solutions to the wave equation on light cones in Minkowski space. The resulting expression generalizes to massless fields of arbitrary spin -- including the electromagnetic field, Weyl fermions, and the linearized Weyl tensor -- on conformally flat space-times. In some non-conformally flat space-times there may exist conserved charges on very special null hypersurfaces. Using the conformal GHP formalism I prove the existence of conserved Aretakis charges on extremal Killing horizons. In the absence of exact conservation laws it is still useful to extend the definition for NP constants to some asymptotically flat curved space-times, where the conservation laws become approximate conservation laws which rapidly approach exact conservation laws at null infinity. I derive explicit expressions for spherically symmetric space-times.
title Newman-Penrose-like exact and approximate conservation laws: a covariant and conformal formulation
topic General Relativity and Quantum Cosmology
Mathematical Physics
url https://arxiv.org/abs/2507.02237