Supernovae and photon frequency shift induced by the Standard-Model Extension

We revisit for 714 SNeIa the discrepancy between the red-shift associated to the distance modulus $\mu$ and the spectroscopic red-shift. Previous work has shown that the total red-shift $z$ might be a combination of the expansion red-shift $z_{\rm C}$ and of a static, blue or red shift $z_{\rm LSV}(r)$, $r$ being the comoving distance. The latter is due to the energy non-conservation of the photon propagating through Electro-Magnetic (EM) background fields (host galaxy, intergalactic and Milky Way), under Lorentz(-Poincar\'e) Symmetry Violation (LSV), associated to the Standard-Model Extension (SME). The non-conservation stems from the vacuum expectation value of the vector and tensor LSV fields. For zero radiation $\Omega_{\rm rad}$ and curvature $\Omega_{\rm k}$ densities, and matter density $\Omega_m = 0.28$, the SN1a positions in the ($\mu$, z) plan are recovered according to the different strengths, orientations, alignments and space-time dependencies of the EM fields and LSV components. The LSV vacuum energy may be thus tantamount to $\Omega_\Lambda \simeq 0.7$, but unrelated to an accelerated expansion. We present models with red or blue-shifts $z_{\rm LSV}$, below $10\%$ of $z$. The $\nu$ frequency variation is below $10^{-19} \Delta \nu/\nu$ per m.