Quasi-local energy-momentum and energy flux at null infinity

TL;DR

This paper evaluates the null infinity limit of gravitational energy-momentum and flux using covariant Hamiltonian quasi-local expressions and NP spin coefficients, confirming expected Bondi quantities through three embedding methods.

Contribution

It introduces three embedding approaches to compute reference contributions, successfully reproducing Bondi energy and flux at null infinity.

Findings

All embedding methods yield the expected Bondi energy.

All methods produce the correct Bondi energy flux.

The approach confirms the validity of covariant Hamiltonian quasi-local expressions.

Abstract

The null infinity limit of the gravitational energy-momentum and energy flux determined by the covariant Hamiltonian quasi-local expressions is evaluated using the NP spin coefficients. The reference contribution is considered by three different embedding approaches. All of them give the expected Bondi energy and energy flux.