An investigation of a varying G through Strong Lensing and SNe Ia observations

TL;DR

This study investigates whether the gravitational constant G varies over cosmic time using strong lensing and supernova data, finding no significant evidence but highlighting the potential of astrophysical observations to test fundamental physics.

Contribution

It introduces a method to constrain G(z) variations using combined lensing and supernova data, providing current limits and future prospects.

Findings

No significant evidence for G variation within current errors.

Constraints are compatible with constant G.

Future data could tighten these constraints.

Abstract

In this paper, we analyze the potential variation of the gravitational constant $G$ using data from strong gravitational lensing systems and Type Ia supernovae. Testing $G(z)$ parameterizations where $G(z) = G_0(1 + G_1z)$ and $G(z) = G_0(1 + z)^{G_1}$, we also account for the influence of $G$ on the luminosity of SNe Ia through the Chandrasekhar mass-luminosity relation. Only the flat universe hypothesis is considered. Constraints from 158 lensing systems and the Pantheon+ sample show no significant evidence of $G$ variation. However, although the results are compatible with no variation, the errors are not yet sufficiently restrictive to rule out any variation of $G$ with high statistical confidence. This study highlights the viability of using combined astrophysical data to probe variations in fundamental constants, suggesting that future surveys could refine these constraints.