Gravitational redshift and the equivalence principle

Two problems have long been confused with each other: the gravitational redshift as discussed by the equivalence principle; and the Doppler shift observed by a detector which moves with constant proper acceleration away from a stationary source. One here distinguishes these two problems and give for the first time a solution of the former which is ''exact'' within the context of the equivalence principle in a sense discussed. The equivalence principle leads to transformations between flat spacetimes. These are analyzed, and a generalized Lorentz transformation is proposed which covers transformations from inertial to uniformly accelerated frames of reference