Relativistic Quantum Field Inertia and Vacuum Field Noise Spectra

The equivalence statements for quantum scalar field vacuum states that havebeen used for the thermal-like Hawking effect and Unruh effect are surveyed.An important ingredient in this framework is the concept of a vacuum field noisespectrum, by which one can obtain information about the curvature invariants ofclassical worldlines (relativistic classical trajectories). It is argued, in the spiritof the free-fall-type universality, that the preferred quantum field vacua withrespect to accelerated worldlines should be chosen from the class of all thosepossessing stationary spectra for their quantum fluctuations. For scalar quantumfield vacua there are six stationary cases, as shown by Letaw some time ago,and reviewed here. However, nonstationary vacuum noises can be treated by afew mathematical methods that are mentioned as well. Since the informationabout the kinematical curvature invariants of the worldlines is of radiometricorigin, suggestions are given on the more useful application of such an academicformalism to radiation and beam radiometric standards for high-energyaccelerators and in astrophysics. We conclude with a look at related axiomaticquantum field topics and some other recent work.