Unruh effect and detectors moving in a circle

[asimov42]

Hi all,

I have a question about the Unruh effect. I've read that a detector will only register the effect (i.e., the thermal bath) when the Rindler horizon is visible - in turn, a detector accelerating in a circle (changing direction but not speed) would not measure the thermal effect because no horizon is visible. Can anyone shed light on whether this is, in fact, correct?

 

[Prathyush]

Very interesting question, One has to do mode transformation and see if positive frequency modes transform into negetive frequency modes.