Emerging high-redshift cosmological probes, in particular quasars (QSOs), show a preference for larger matter densities, ${\mathrm{\Omega }}_m\approx 1$, within the flat $\mathrm{\Lambda }\mathrm{CDM}$ framework. Here, using the Risaliti-Lusso relation for standardizable QSOs, we demonstrate that the QSOs recover the same Planck-$\mathrm{\Lambda }\mathrm{CDM}$ universe as type Ia supernovae (SN), ${\mathrm{\Omega }}_m\approx 0.3$ at lower redshifts $0<z\lesssim 0.7$, before transitioning to an Einstein–de Sitter universe (${\mathrm{\Omega }}_m=1$) at higher redshifts $z\gtrsim 1$. We illustrate the same trend, namely increasing ${\mathrm{\Omega }}_m$ and decreasing $H_0$ with redshift, in SN but poor statistics prevent a definitive statement. We explain physically why the trend may be expected and show the intrinsic bias through non-Gaussian tails with mock SN data. Our results highlight an intrinsic bias in the flat $\mathrm{\Lambda }\mathrm{CDM}$ universe, whereby ${\mathrm{\Omega }}_m$ increases, $H_0$ decreases and $S_8$ increases with effective redshift, thus providing a new perspective on $\mathrm{\Lambda }\mathrm{CDM}$ tensions; even in a Planck-$\mathrm{\Lambda }\mathrm{CDM}$ universe the current tensions may be expected.

Close

PrevNext

View figure in article

• Cosmology
• Dark energy
• Novae & supernovae