Excising das All: Evolving Maxwell waves beyond scri

TL;DR

This paper presents a numerical method for propagating electromagnetic waves through null infinity by using a conformal compactification and an artificial cosmological constant to facilitate excision boundary conditions.

Contribution

It introduces a novel approach to control causal structure near null infinity, enabling excision techniques in numerical wave propagation simulations.

Findings

Successful implementation of excision boundary conditions near null infinity.

Controlled causal structure via artificial cosmological constant.

Preliminary results with electromagnetic waves in static spacetime.

Abstract

We study the numerical propagation of waves through future null infinity in a conformally compactified spacetime. We introduce an artificial cosmological constant, which allows us some control over the causal structure near null infinity. We exploit this freedom to ensure that all light cones are tilted outward in a region near null infinity, which allows us to impose excision-style boundary conditions in our finite difference code. In this preliminary study we consider electromagnetic waves propagating in a static, conformally compactified spacetime.