  Nonperturbative analysis of quantum entanglement and quantum teleportation
protocol using oscillator variables carried by observers in relativistic motion
under the continuous influence of the environment is given. The full time
evolution of quantum entanglement among static and accelerated observers is
studied. The environment plays a dual role. While it creates bipartite and
tripartite entanglement among observers even when the initial state is
separable, it suppresses the entanglement via decoherence. Motivated by the
black hole information problem, we consider quantum teleportation between
static and accelerated observers. Acceleration of the observer suppresses
fidelity of teleportation. Some of the quantum information escapes outside of
the horizon in the form of bipartite and tripartite entanglement during the
teleportation process. Explicit calculation of information loss is provided. In
addition to the loss due to the interaction with the environment, there is an
intrinsic loss originated in a measurement process. We discuss the implications
of our results on the black hole case.
