Primordial constraint on the spatial dependence of the Newton constant

TL;DR

This paper investigates how potential variations in the Newton constant at cosmological scales could influence cosmic microwave background observations, providing new constraints on fundamental physics through cosmological data analysis.

Contribution

It introduces a novel method to constrain the spatial dependence of the Newton constant using CMB data and primordial nucleosynthesis measurements.

Findings

Constraints on Newton constant variation at recombination

Implications for the strong equivalence principle

Enhanced understanding of gravity's role in early universe

Abstract

A Nordtvedt effect at cosmological scales affects the acoustic oscillations imprinted in the cosmic microwave background. The gravitational baryonic mass density of the universe is inferred at the first peak scale from WMAP data. The independent determination of the inertial baryonic mass density through the measurement of the deuterium abundance in the framework of standard big bang nucleosynthesis leads to a new constraint on a possible violation of the strong equivalence principle at the recombination time.