In his this book, Hatfield calls ghosts the negative states appearing in the covariant (Gupta-Bleuler) quantization prescription of the electromagnetic field (page 89). When discussing Yang-Mills fields, he comments on the Faddeev-Popov ghosts (page 356).

He mentions that the 'ghost' nomenclature is used in different ways in these two contexts: the negative states and the representations of the Faddeev-Popov determinant. It made me question if the two cannot be really connected.

Can we relate the (decoupling) Faddeev-Popov ghosts of QED in Lorenz gauge with the longitudinal and scalar photons of Gupta-Bleuler? Or maybe the only similarity between them is that they can be separated (in some sense) of the physical particles? (even if the longitudinal and scalar ones contribute to loop corrections)


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.