Cosmology and the massive photon frequency shift in the Standard-Model
  Extension
  The total red shift $z$ might be recast as a combination of the expansion red
shift and a static shift due to the energy-momentum tensor non-conservation of
a photon propagating through Electro-Magnetic (EM) fields. If massive, the
photon may be described by the de Broglie-Proca (dBP) theory which satisfies
the Lorentz(-Poincar\'e) Symmetry (LoSy) but not gauge-invariance. The latter
is regained in the Standard-Model Extension (SME), associated with LoSy
Violation (LSV) that naturally dresses photons of a mass. The non-conservation
stems from the vacuum expectation value of the vector and tensor LSV fields.
The final colour (red or blue) and size of the static shift depend on the
orientations and strength of the LSV and EM multiple fields encountered along
the path of the photon. Turning to cosmology, for a zero $\Omega_{\Lambda}$
energy density, the discrepancy between luminosity and red shift distances of
SNeIa disappears thanks to the recasting of $z$. Massive photons induce an
effective dark energy acting `optically' but not dynamically.
