Using the logarithmic superfluid model of physical vacuum, one can formulate an essentially quantum post-relativistic theory, which successfully recovers Einstein’s theory of relativity in low-momenta limit, but otherwise has different foundations and predictions. We present an analytical example of the dispersion relation and show that it should have a Landau form which ensures the suppression of dissipative fluctuations. We show that in the low-momentum sector of the theory, a dispersion relation becomes relativistic with small deformations, such that a photon acquires effective mass, but a much more complex picture arises at large momenta.