Null-Field Radiationless Sources: Comment

TL;DR

This paper discusses null-field radiationless sources, commenting on prior work and extending the theory from Minkowski space to curvilinear space, providing a broader mathematical framework.

Contribution

It generalizes the theory of null-field sources from Minkowski space to curvilinear space, enhancing the mathematical understanding of radiationless sources.

Findings

Extended null-field source theory to curvilinear coordinates

Provided a mathematical framework for radiationless sources in curved space

Commented on and clarified previous Minkowski space results

Abstract

We elaborate upon a recent paper of E. Hurwitz and G. Gbur [Opt. Lett. {\bf 39}, 6529 (2014)], dealing with null-field sources. After commenting on their theory in Minkowski space, we show how the theory can be conveniently generalized to the case of curvilinear space.