Quantized scalar field in rotating coordinates

Second quantization of the free scalar field is carried out in rotating coordinates and the spectrum of vacuum fluctuations is calculated for an orbiting observer using these coordinates. Normal-mode decomposition is identical to that in Minkowski coordinates except for the definition of positive-frequency modes. Unlike the uniformly accelerating observer, the orbiting observer predicts that the Minkowski vacuum will contain no particles as he would define them. The spectrum of vacuum fluctuations is composed of the usual zero-point energy plus a contribution arising from the observer's acceleration. The latter is not, as with uniformly accelerated motion, thermal. The peak energy appears to be dependent only on the torsion of the observer's world line