Speaker
Description
The novel observable \hat{J}, capturing the evolution of the combined gravitational potential Ψ + Φ, provides a powerful and model-independent test of gravity. As I will demonstrate in this talk, its full capacity comes into play when being combined with further cosmological observables. Together with measurements of the growth of structure \hat{f}, accessible via redshift-space distortions, the quantity \hat{J} enables us to reconstruct the so-called E_G statistic. This statistic has been introduced as a robust consistency check of general relativity. However, previous measurements of E_G necessitated a single spectroscopic galaxy sample to measure both galaxy clustering and velocity-density correlations, to cancel the impact of the galaxy bias. In our recent work (NG, C. Bonvin & I. Tutusaus, 2024), we present a novel approach to measuring E_G which is free of this limitation: It directly combines two model-independent observables - \hat{f} and \hat{J}. Our method leads to four new measurements of E_G which provide a considerable improvement in precision compared to previous ones. We find a confirmation of general relativity at three redshifts, and a mild tension of 2.5\sigma at z=0.47.
