Physical Aspects of the Space-Time Torsion

TL;DR

This paper reviews quantum aspects of space-time torsion, exploring its theoretical foundations, potential physical effects, experimental bounds, and the conditions under which torsion could be a propagating field consistent with quantum theory.

Contribution

It provides a comprehensive analysis of quantum torsion, including conditions for propagating torsion fields and implications for detectability and theoretical consistency.

Findings

Propagating torsion requires torsion mass to be much greater than fermion masses.

Universal fermion-torsion interaction implies torsion has a very large mass.

Background torsion bounds are established from existing literature.

Abstract

We review many quantum aspects of torsion theory and discuss the possibility of the space-time torsion to exist and to be detected. The paper starts, in Chapter 2, with an introduction to the classical gravity with torsion, that includes also interaction of torsion with matter fields. In Chapter 3, the renormalization of quantum theory of matter fields and related topics, like renormalization group, effective potential and anomalies, are considered. Chapter 4 is devoted to the action of particles in a space-time with torsion, and to possible physical effects generated by the background torsion. In particular, we review the upper bounds for the background torsion which are known from the literature. In Chapter 5, the comprehensive study of the possibility of a theory for the propagating completely antisymmetric torsion field is presented. We show, that the propagating torsion may be consistent with the principles of quantum theory only in the case when the torsion mass is much greater than the mass of the heaviest fermion coupled to torsion. Then, universality of the fermion-torsion interaction implies that torsion itself has a huge mass, and can not be observed in realistic experiments. In Chapter 6, we briefly discuss the string-induced torsion and the possibility to induce torsion action and torsion itself through the quantum effects of matter fields.