Gravitational Phase Operator and Cosmic Strings

TL;DR

This paper introduces a quantum gravitational phase operator linked to the Poincare group, applies it to spinning cosmic strings, and derives a new Einstein-Cartan solution suggesting possible gravitational torsion effects.

Contribution

It formulates a quantum equivalence principle using a gravitational phase operator and provides a new exact torsion-inclusive solution for cosmic strings.

Findings

Spinning cosmic strings may contain gravitational torsion.

A new exact Einstein-Cartan solution for cosmic strings is derived.

Quantum effects imply spacetime points may lack meaning in quantum gravity.

Abstract

A quantum equivalence principle is formulated by means of a gravitational phase operator which is an element of the Poincare group. This is applied to the spinning cosmic string which suggests that it may (but not necessarily) contain gravitational torsion. A new exact solution of the Einstein- Cartan-Sciama-Kibble equations for the gravitational field with torsion is obtained everywhere for a cosmic string with uniform energy density, spin density and flux. A novel effect due to the quantized gravitational field of the cosmic string on the wave function of a particle outside the string is used to argue that spacetime points are not meaningful in quantum gravity.