  A quantum theory of gravity implies a fine-grained structure of spacetime,
which can be conveniently modeled as some form of pixelation at the Planck
scale, with potentially observable consequences. In this work, we build upon
previous results to investigate the effect of pixelation on the quantum vacuum,
making use of the framework of Doubly Special Relativity (DSR). At the center
of the DSR approach is an observer dependent length scale, defining the
pixelation of spacetime. A key feature of quantum field theory in DSR is the
dispersive nature of the vacuum state and the associated appearance of
curvature in momentum space. As a result, the standard treatment of the
renormalized stress-energy-momentum tensor acquires correction terms. As an
illustration, we present here a calculation of the thermal vacuum and modified
Casimir effect, using both modified propagators and momentum measures. We
choose a consistent choice of momentum space metric that both generates the
modified dispersion relations we use and preserves the Lorentz invariant
character of the results obtained. Put together this constitutes a consistent
calculation framework we can apply to other more complex scenarios.
