Testing the cosmological Poisson equation in a model-independent way

• Verfasst von: Zheng, Ziyang [VerfasserIn]
• Verfasst von: Sakr, Ziad [VerfasserIn]
• Verfasst von: Amendola, Luca [VerfasserIn]
• Titel: Testing the cosmological Poisson equation in a model-independent way
• Verf.angabe: Ziyang Zheng, Ziad Sakr, Luca Amendola
• E-Jahr: 2024
• Jahr: June 2024
• Umfang: 9 S.
• Illustrationen: Illustrationen
• Fussnoten: Online verfügbar: 16. April 2024, Artikelversion: 18. April 2024 ; Gesehen am 18.09.2024
• Titel Quelle: Enthalten in: Physics letters
• Ort Quelle: Amsterdam : North-Holland Publ., 1967
• Jahr Quelle: 2024
• Band/Heft Quelle: 853(2024) vom: Juni, Artikel-ID 138647, Seite 1-9
• ISSN Quelle: 1873-2445
• DOI: doi:10.1016/j.physletb.2024.138647
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Cosmological parameters
• Sach-SW: Cosmology: observations
• Sach-SW: Cosmology: theory
• Sach-SW: Dark energy
• K10plus-PPN: 1902904605

Abstract

We show how one can test the cosmological Poisson equation by requiring only the validity of three main assumptions: the energy-momentum conservation equations of matter, the equivalence principle, and the cosmological principle. We first point out that one can only measure the combination M≡Ωm(0)μ, where μ quantifies the deviation of the Poisson equation from the standard one and Ωm(0) is the fraction of matter density at present. Then we employ a recent model-independent forecast for the growth rate f(z) and the expansion rate E(z) to obtain constraints on M for a survey that approximates a combination of the Dark Energy Spectroscopic Instrument (DESI) and Euclid. We conclude that a constant M can be measured with a relative error σM=4.5%, while if M is arbitrarily varying in redshift, it can be measured only to within 13.4% (1 σ c.l.) at redshift z=0.9, and 15-22% up to z=1.5. We also project our constraints on some parametrizations of M proposed in literature, while still maintaining model-independence for the background expansion, the power spectrum shape, and the non-linear corrections. Generally speaking, as expected, we find much weaker model-independent constraints than found so far for such models. This means that the cosmological Poisson equation remains quite open to various alternative gravity and dark energy models.