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arXiv · 2605.24884

Preliminary cosmological results using extreme accretors Quasar formalism

Rodrigo Sandoval-Orozco·Castalia Alenka Negrete·Paola Marziani·Jackson Levi Said
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Abstract

We revisited the xA Quasar formalism from the cosmological point of view, where a completely cleaned and standardized sample is compiled from different literature references. This allowed us to test three different cosmological models including $w$CDM and $w_0w_a$CDM and $\Lambda$CDM resulting in a Hubble constant estimation of $H_0 = 69.8 \pm 2.2$~$\mathrm{km\,s^{-1}\,Mpc^{-1}}$ for the compiled sample alone and $H_0=69.0 \pm 0.9$~$\mathrm{km\,s^{-1}\,Mpc^{-1}}$ when combined with Type I Supernovae (SNIa), Cosmic Chronometers and the Cosmic Microwave Background (CMB) distance priors. Using both the $w$CDM and $w_0w_a$CDM a weak Bayesian preference for the dynamical dark energy models over the $\Lambda$CDM model was found. A comparative analysis was performed with other AGN based methods in cosmology like the Reverberation Mapping, the X-Ray and UV non-linear relation and the Angular distance measurements. We conclude that the significant intrinsic dispersion is a key issue present in all samples. Overcoming this dispersion is key to establish xA and other AGN samples as robust and precise cosmological probes.

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Rodrigo Sandoval-Orozco, Castalia Alenka Negrete, Paola Marziani, Jackson Levi Said. 2026-05-24. Preliminary cosmological results using extreme accretors Quasar formalism. https://doi.org/10.1016/j.dark.2026.102331

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