  Lorentz violation frequently induces modified dispersion relations that can
yield space-like states that impede the standard quantization procedures. In
certain cases, an extended hamiltonian formalism can be used to define
observer-covariant normalization factors for field expansions and phase space
integrals. These factors extend the theory to include non-concordant frames in
which there are negative-energy states. This formalism provides a rigorous way
to quantize certain theories containing space-like states and allows for the
consistent computation of Cherenkov radiation rates in arbitrary frames and
avoids singular expressions.
