Barbero-Immirzi Value from Experiment

TL;DR

This paper derives a new experimental constraint on the Barbero-Immirzi parameter in Loop Quantum Gravity by analyzing the Shapiro time delay data from the Cassini spacecraft within a Scalar-Tensor gravity framework.

Contribution

It introduces a novel method to estimate the Barbero-Immirzi parameter using experimental gravitational data, linking quantum gravity parameters to observable phenomena.

Findings

Barbero-Immirzi parameter constrained by Cassini data

Experimental limit on scalar-tensor coupling from time delay measurements

Provides a bridge between quantum gravity and experimental tests

Abstract

We consider General Relativity as a limit case of the Scalar-Tensor theory with Barbero-Immirzi field when the field tends to a constant. We use Shapiro time delay experimental limit of $1/w = (2.1 \pm 2.3)10^{-5}$ provided by the Cassini spacecraft to find the Barbero-Immirzi parameter value.