  The propagators of the Dirac fermions on the expanding portion of the
(1+3)-dimensional de Sitter spacetime are considered as mode sums in momentum
representation with a fixed vacuum of Bunch-Davies type. The principal result
reported here is a new integral representation of the Feynman propagators of
the massive and left-handed massless Dirac fields which can be used for
deriving the Feynman rules of the de Sitter QED in Coulomb gauge or of an
extended QFT.
