A third hypothesis on the origin of the redshift: Application to the Pioneer 6 data

We propose a third general mechanism (beyond the Doppler and Einstein effects) to account for the redshift. We model the interstellar medium by a low density Fermi gas and its interaction with light by standard QED. Applying the techniques of the stochastic limit of quantum field theory, we prove a general redshift theorem. This result fits satisfactorily both Pioneer 6 and solar limb redshift data