Estimating Energy-Momentum and Angular Momentum Near Null Infinity

TL;DR

This paper develops gauge-invariant formulas to estimate energy-momentum and angular momentum near null infinity, aiding numerical relativity by accounting for finite-size effects and providing practical tools for analyzing gravitational systems.

Contribution

It introduces new gauge-invariant formulas for energy-momentum and angular momentum near null infinity, applicable to numerical relativity and finite-size effect estimation.

Findings

Formulas are gauge-invariant and applicable to numerical work.

Provides estimates of finite-size effects.

Applicable to systems with spherical topology near null infinity.

Abstract

The energy-momentum and angular momentum contained in a spacelike two-surface of spherical topology are estimated by joining the two-surface to null infinity via an approximate no-incoming-radiation condition. The result is a set of gauge-invariant formulas for energy-momentum and angular momentum which should be applicable to much numerical work; it also gives estimates of the finite-size effects.