Alexander Shalyt-Margolin. The Equivalence Principle, Measurability, Gravity at Low and High Energies, and Spacetime Foam
Natural Sciences / Physics / Gravitation Theory (Relativity)
Submitted on: Apr 22, 2019, 07:05:39
Description: The present paper is devoted to further studies of quantum theory and gravity in terms of the {bf measurability} notion on the basis of the previous authorâE™s works. In the beginning the applicability limit of Einstein's Equivalence Principle (EP) is considered. It is noted that in this case a natural upper limit is associated with the Planck scales (or same Planck energies) because, due to the modern knowledge about these scales, the well-known spacetime geometry should be replaced by the spacetime foam on account of great fluctuations of the metric. It is shown that a real applicability limit of EP may be considerably lower than the Plank scales. Without due regard to this fact, one can obtain senseless results from estimation of the relevant quantities within the scope of the conventional Quantum Field Theory. In the second part of the paper the earlier obtained results are applied to study the spacetime foam in the case of a {bf measurable} consideration. It is demonstrated that {bf measurability} allows for a new approach to investigation of quantum fluctuations of the metric, especially at high (Planck) energies, i.e. in the quantum-gravitational region, leading to new approaches to studies of the spacetime foam.