Validation of classical modeling of single-photon pulse propagation

"It is well-known to those who know it" that single-photon interference experiments can be modeled classi-cally [S. Barnett, Phys. Scr. 97, 114004 (2022)]. When a single-photon light pulse was split by a biprism, good agreement with a classical fit was obtained and the photon was counted only once, consistent with a probabilistic interpretation [V. Jacques et al., Eur. Phys. J. D 35, 561 (2002)]. A justification for this "well know result of quantum optics" is implicit in the work by Hawton [Phys. Rev A 104, 052211 (2021)] where a real covariant field describing a single photon is first quantized. Here the theoretical basis of this result is reviewed and the theory is extended to multiphoton states. The crucial role of the charge-parity-time theorem in coupling to charged matter and resolution of the photon localization problem is discussed.