2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197506We consider the behavior of the photon number integral under inversion, concentrating on euclidean space. The discussion may be framed in terms of an additive differential $I$ which arises under inversions. The quantity $\int \int I$ is an interesting integral invariant whose value characterizes different configurations under inversion.13 pages, 3 figuresHigh Energy Physics - TheoryMathematical Physicstext