Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10725749 | Physics Letters B | 2010 | 6 Pages |
Abstract
It is well known that a detector, coupled linearly to a quantum field and accelerating through the inertial vacuum with a constant acceleration g, will behave as though it is immersed in a radiation field with temperature T=(g/2Ï). We study a generalization of this result for detectors moving with a time-dependent acceleration g(Ï) along a given direction. After defining the rate of excitation of the detector appropriately, we evaluate this rate for time-dependent acceleration, g(Ï), to linear order in the parameter η=gË/g2. In this case, we have three length scales in the problem: gâ1, (gË/g)â1 and Ïâ1 where Ï is the energy difference between the two levels of the detector at which the spectrum is probed. We show that: (a) When Ïâ1âªgâ1âª(gË/g)â1, the rate of transition of the detector corresponds to a slowly varying temperature T(Ï)=g(Ï)/2Ï, as one would have expected. (b) However, when gâ1âªÏâ1âª(gË/g)â1, we find that the spectrum is modified even at the orderO(η). This is counter-intuitive because, in this case, the relevant frequency does not probe the rate of change of the acceleration since (gË/g)âªÏ and we certainly do not have deviation from the thermal spectrum when gË=0. This result shows that there is a subtle discontinuity in the behavior of detectors with gË=0 and gË/g2 being arbitrarily small. We corroborate this result by evaluating the detector response for a particular trajectory which admits an analytic expression for the poles of the Wightman function.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
Dawood Kothawala, T. Padmanabhan,