  QED in two-dimensional Minkowski space contains a single physical state as
seen by an inertial observer or by a constantly accelerating Rindler observer.
However in Feynman gauge if one takes a generic representative of the physical
Minkowski state and traces over all left Rindler states, one does not arrive at
a physical right Rindler state, but rather at a "density matrix" with negative
eigenvalues for negative norm states corresponding intuitively to the radiation
of uncorrelated temporal photons and ghosts. This reflects the fact that states
that are exact under the Minkowski BRST operator are not necessarily exact or
even closed under the Rindler BRST operator. Such situations are avoided when
there are quantum corrections to the Hamiltonian that eliminate the horizons,
which yield Mathurian fuzzball solutions.
