From Cavendish to PLANCK: Constraining Newton's Gravitational Constant with CMB Temperature and Polarization Anisotropy

TL;DR

This paper uses recent cosmic microwave background data and Big Bang Nucleosynthesis constraints to improve bounds on possible variations of Newton's gravitational constant over cosmic history.

Contribution

It provides new, tighter constraints on G's variation from CMB and BBN data, and forecasts future experimental sensitivities.

Findings

Current CMB data constrain G variation to 10%.

Including BBN data improves constraints to 3%.

Future CMB experiments could reach 0.4% precision.

Abstract

We present new constraints on cosmic variations of Newton's gravitational constant by making use of the latest CMB data from WMAP, BOOMERANG, CBI and ACBAR experiments and independent constraints coming from Big Bang Nucleosynthesis. We found that current CMB data provide constraints at the 10% level, that can be improved to 3% by including BBN data. We show that future data expected from the Planck satellite could constrain G at the 1.5% level while an ultimate, cosmic variance limited, CMB experiment could reach a precision of about 0.4%, competitive with current laboratory measurements.