New measurements of $E_G$: Testing General Relativity with the Weyl potential and galaxy velocities
| Autor: | Grimm, Nastassia, Bonvin, Camille, Tutusaus, Isaac |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We combine measurements of galaxy velocities from galaxy surveys with measurements of the Weyl potential from the Dark Energy Survey to test the consistency of General Relativity at cosmological scales. Taking the ratio of two model-independent observables - the growth rate of structure and the Weyl potential - we obtain new measurements of the $E_G$ statistic with precision of $5.8-10.7\%$ at four different redshifts. These measurements provide a considerable improvement to past measurements of $E_G$. They confirm the validity of General Relativity at three redshifts, while displaying a tension of $2.5\sigma$ at $z=0.47$ as a consequence of the tension found in the measurements of the Weyl potential. Contrary to conventional methods that rely on a common galaxy sample with spectroscopic resolution to measure two types of correlations, we directly combine two observables that are independent of the galaxy bias. This provides a novel approach to testing the relation between the geometry of our Universe and the motion of galaxies with improved precision. Comment: 7 pages, 2 figures |
| Databáze: | arXiv |
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