Highly covariant quantum lattice gas model of the Dirac equation

Abstract: We revisit the quantum lattice gas model of a spinor quantum field theory-the smallest scale particle dynamics is partitioned into unitary collide and stream operations. The construction is covariant (on all scales down to a small length {\ell} and small time {\tau} = c {\ell}) with respect to Lorentz transformations. The mass m and momentum p of the modeled Dirac particle depend on {\ell} according to newfound relations m = mo cos (2{\pi}{\ell}/{\lambda}) and p = (h/2{\pi}{\ell}) sin(2{\pi}{\ell}/{\lambda}), respectively, where {\lambda} is the Compton wavelength of the modeled particle. These relations represent departures from a relativistically invariant mass and the de Broglie relation-when taken as quantifying numerical errors the model is physically accurate when {\ell} {\ll} {\lambda}. Calculating the vacuum energy in the special case of a massless spinor field, we find that it vanishes (or can have a small positive value) for a sufficiently large wave number cutoff. This is a marked departure from the usual behavior of such a massless field.