The Equivalence Principle Applicability Boundaries, QFT in Flat Space and Measurability I. Free Quantum Fields

Abstract

The present paper continues a study of a quantum field theory in terms of the measurability notion introduced in the previous author’s works. The first part of this paper is devoted to the analysis of the applicability limit of Einstein’s Equivalence Principle (EP). It is shown that neglecting the applicability limit of EP one can obtain senseless results on estimation of the relevant quantities within the scope of the well-known Quantum Field Theory (QFT). Besides, such a neglect may be responsible for ultraviolet divergences in a theory. In the second part of the work the general principles and mathematical apparatus are presented for framing QFT in terms of the measurability notion. Next, the author investigates QFT in the measurable form for free quantum fields at low energies E ˝ Ep, given the limitations imposed by the boundary of EP applicability. In the conclusion, a general form is given for gauge theories in a measurable consideration at low energies.