  In this paper we re-investigate the Bogoliubov transformations which relate
the Minkowski inertial vacuum to the vacuum of an accelerated observer. We
implement the transformation using a non-unitary operator used in formulations
of irreversible systems by Prigogine. We derive a Lyapunov function which
signifies an irreversible time flow. We extend the formalism to the black hole
space-time which has similar near-horizon geometry of an accelerated observer,
and in addition show that thermalization is due to presence of black hole and
white hole regions. Finally we discuss an attempt to generalize quantum field
theory for accelerated frames using this new connection to Prigogine
transformations.
