1. Assessing cosmic acceleration with the Alcock–Paczyński effect in the SDSS-IV quasar catalogue.
- Author
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Melia, Fulvio, Qin, Jin, and Zhang, Tong-Jie
- Subjects
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DARK matter , *ASTRONOMICAL surveys , *QUASARS , *CATALOGS , *REDSHIFT , *ACTIVE galaxies - Abstract
The geometry of the Universe may be probed using the Alcock–Paczyński (AP) effect, in which the observed redshift size of a spherical distribution of sources relative to its angular size varies according to the assumed cosmological model. Past applications of this effect have been limited, however, by a paucity of suitable sources and mitigating astrophysical factors, such as internal redshift-space distortions and poorly known source evolution. In this Letter , we introduce a new test based on the AP effect that avoids the use of spatially bound systems, relying instead on sub-samples of quasars at redshifts z ≲ 1.5 in the Sloan Digital Sky Survey IV, with a possible extension to higher redshifts and improved precision when this catalogue is expanded by upcoming surveys. We here use this method to probe the redshift-dependent expansion rate in three pertinent Friedmann–Lemaître–Robertson–Walker cosmologies: Λ cold dark matter (ΛCDM), which predicts a transition from deceleration to acceleration at z ∼ 0.7; Einstein–de Sitter, in which the Universe is always decelerating; and the R h = ct universe, which expands at a constant rate. ΛCDM is consistent with these data, but R h = ct is favoured overall. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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