Unruh effect without Rindler horizon

Understand

We investigate the Unruh effect for a massless scalar field in the two dimensional Minkowski space in the presence of a uniformly accelerated perfect mirror, with the trajectory of the mirror chosen in such a way that the mirror completely masks the Rindler horizon from the space-time region of interest.

• We find that the characteristic thermodynamical properties of the effect remain unchanged, i.e.
• the response of a uniformly co-accelerated Unruh detector and the distribution of the Rindler particles retain their thermal form.
• However, since in this setup there are no unobserved degrees of freedom of the field the thermal statistics of the Rindler particles is inconsistent with an initial pure vacuum, which leads us to reconsider the problem for the more physical case when the mirror is inertial in the past.