title: Theorem on the uniqueness of the generalized radiance.
abstract: We study the consequences of requiring that the generalized radiance depend linearly on the cross-spectral density, be zero wherever the field amplitude is zero, and can be defined independently of coordinate translations. We show that these requirements determine the generalized radiance uniquely, and that the resulting definition is independent of coordinate rotations.
authors.forename: A
authors.initials: A
authors.lastname: Walther