Derivation of the Dirac Equation from Principles of Information Processing

G. M. D'Ariano, P. Perinotti

Published 2013-06-08, updated 2014-12-28Version 2

We show how the Dirac equation in three space-dimensions emerges from the large-scale dynamics of the minimal nontrivial quantum cellular automaton satisfying unitariety, locality, homogeneity, and discrete isotropy, without using the relativity principle. The Dirac equation is recovered for small wave-vector and inertial mass, whereas Lorentz covariance is distorted in the ultra-relativistic limit. The automaton can thus be regarded as a theory unifying scales from Planck to Fermi. A simple asymptotic approach leads to a dispersive Schroedinger equation describing the evolution of narrow-band states at all scales.