Experiments on the Violation of Electromagnetic Gauge Symmetry by Yang-Mills Gravity Using Josephson Effects in Superconductors

TL;DR

This paper investigates how Yang-Mills gravity, a quantum gravity theory with translational gauge symmetry, affects Josephson effects in superconductors and proposes an experimental test to detect potential violations of electromagnetic gauge invariance caused by gravity.

Contribution

It introduces a novel experimental approach to test Yang-Mills gravity's influence on superconducting Josephson junctions through measurable voltage differences.

Findings

Yang-Mills gravity modifies phase gradients near Earth surface.

The gauge invariance of Josephson junction voltages is affected by gravity.

Predicted voltage difference in free fall is detectable with current technology.

Abstract

Yang-Mills gravity is a quantum theory of gravity with translational gauge symmetry that is based on a flat space-time. The universal coupling of all quantum fields to quantum Yang-Mills gravity is based on the replacement of $\partial_\mu$ by the translational gauge covariant derivative $(\partial_\mu +g\phi_\mu^\nu \partial_\nu)$ in the Lagrangians of non-gravitational fields. Near the surface of the Earth, Yang-Mills gravity causes the phase gradient $\partial_k \theta$ to be altered by a factor of $h_1\approx(1- g\phi)\approx 1- 7\times 10^{-10}$. In addition, the usual gauge-invariant combination of phase gradients and vector potentials ${\bf A}$ in Josephson junctions is modified and is no longer gauge invariant. The voltage across a Josephson junction is thus affected by the presence of the gravitational coupling constant $g$, and is now given by $V_{g21}\approx Q \int_1^2 [- \mbox{\boldmath$ {\bf \nabla}$} A_0 - h_1^{-2}{\partial {\bf A}}/{\partial t}]\cdot d{\bf s}$. We propose an experimental test of Yang-Mills gravity based on this effect. If one were to compare the voltage across a Josephson junction in a laboratory at rest on Earth with that across a junction in free fall (e.g., in the International Space Station or in a plane maneuvering to simulate zero-gravity such as NASA's now-retired "Vomit Comet"), Yang-Mills gravity predicts a difference on the order of 1 part in $10^{9}$, which should be detectable as the precision of the Josephson junction voltage standard is on the order of a few parts in $10^{10}$.