Linking Tests of Gravity On All Scales: from the Strong-Field Regime to Cosmology

TL;DR

This paper introduces a unified parameter space framework to compare and connect tests of gravity across all scales, from laboratory to cosmology, highlighting an untested regime that may reveal deviations from General Relativity.

Contribution

The authors develop a comprehensive parameter space linking diverse gravity tests and introduce new methods to connect cosmological and local measurements of gravity.

Findings

Identified an untested regime between small-scale and cosmological tests.

Developed a diagrammatic representation of the gravitational parameter space.

Highlighted the potential for new physics to emerge in the untested window.

Abstract

The current effort to test General Relativity employs multiple disparate formalisms for different observables, obscuring the relations between laboratory, astrophysical and cosmological constraints. To remedy this situation, we develop a parameter space for comparing tests of gravity on all scales in the universe. In particular, we present new methods for linking cosmological large-scale structure, the Cosmic Microwave Background and gravitational waves with classic PPN tests of gravity. Diagrams of this gravitational parameter space reveal a noticeable untested regime. The untested window, which separates small-scale systems from the troubled cosmological regime, could potentially hide the onset of corrections to General Relativity.