Probing Quantum Aspects of Gravity

TL;DR

This paper explores how the absence of a super-selection rule in quantum gravity could lead to observable violations of the equivalence principle, suggesting new experimental avenues to probe quantum gravitational effects.

Contribution

It highlights the potential observable consequences of quantum gravity, specifically the violation of the equivalence principle due to superposition of gravitational charges.

Findings

Possible violation of the equivalence principle detectable in experiments.

Terrestrial experiments like neutron interferometry can probe quantum gravity effects.

Cosmic gravitational environment influences local quantum experiments.

Abstract

We emphasize that a specific aspect of quantum gravity is the absence of a super-selection rule that prevents a linear superposition of different gravitational charges. As an immediate consequence, we obtain a tiny, but observable, violation of the equivalence principle, provided, inertial and gravitational masses are not assumed to be operationally identical objects. In this framework, the cosmic gravitational environment affects local experiments. A range of terrestrial experiments, from neutron interferometry to neutrino oscillations, can serve as possible probes to study the emergent quantum aspects of gravity.