We present a simple and systematic method to calculate Rindler noise, which is relevant to an analysis of the Unruh effect, by using the fluctuation-dissipation theorem. To do this, we calculate the dissipative coefficient explicitly from the equations of motion of the detector and the field. This method gives not only the correct answer but also a hint as to the origin of the apparent statistics inversion effect. Moreover, this method is generalized to the Dirac field by using the fermionic fluctuation-dissipation theorem. We can thus confirm that the fermionic fluctuation-dissipation theorem is working properly.

• Received 10 March 1999

DOI:https://doi.org/10.1103/PhysRevD.60.084001