Probing General Relativity on Cosmological Scales in the 2040s
Abstract
General relativity is exquisitely tested in strong-field regimes, yet its validity on cosmological scales remains largely unexplored. Upcoming wide and deep large-scale structure surveys will access the ultra-large, linear scales where relativistic effects - Doppler terms, gravitational redshift, lensing magnification, and potential evolution - leave significant imprints in the clustering of galaxies. These signatures represent unique probes of spacetime that are inaccessible to standard Newtonian analyses but increasingly important as survey volumes grow. We outline the scientific potential of next-generation facilities, such as those envisioned within ESO's Expanding Horizons programme, to deliver the first robust measurements of relativistic effects in large-scale structure through multi-tracer power spectra and the single-tracer bispectrum of high-redshift Lyman-break galaxies. Detecting these contributions would open a new window on gravity, enabling precision tests of general relativity and its alternatives on cosmological scales in the 2040s.
Keywords
Cite
@article{arxiv.2601.05320,
title = {Probing General Relativity on Cosmological Scales in the 2040s},
author = {Federico Montano and Samantha J. Rossiter and Chris Addis and Jessie Hammond and Stefano Camera and Chris Clarkson and Mohamed Yousry Elkhashab and Massimo Guidi and Ofer Lahav and Giovanni Aricò and Sofia Contarini and Pratika Dayal and Giulia Degni and Antonio Farina and Vid Iršič and Federico Marulli and Elena Sarpa and Simone Sartori and Emiliano Sefusatti and Francesco Verdiani and Giovanni Verza},
journal= {arXiv preprint arXiv:2601.05320},
year = {2026}
}
Comments
4 pages, ESO White Paper Call, Expanding Horizons initiative