Implications of DES 5YR SNe Dataset for $\Lambda$CDM
Abstract
Dark Energy Survey five-year supernovae data (DES 5YR SNe) in conjunction with Planck CMB and Dark Energy Spectroscopic Instrument (DESI) BAO data has detected a strong dynamical dark energy deviation from the $\Lambda$CDM model. Here, we shift the focus of DES data to the pressureless matter sector in the $\Lambda$CDM model by studying the matter density parameter $\Omega_m$. Employing frequentist profile likelihoods, we demonstrate that $\Omega_m$ increases with effective redshift in the DES dataset at up to $2.5 \sigma$ level. At the highest redshifts, one encounters negative dark energy densities $\Omega_m > 1$. Our findings corroborate earlier observations in Pantheon and Pantheon+ datasets with an independent SNe dataset with a higher effective redshift. In an appendix, we confirm that curvature $\Omega_k$ decreases with effective redshift disfavouring a flat Universe in higher redshift DES SNe at $> 3 \sigma$. Our choice of $\Omega_k$ prior leads to an underestimation of the tension with a flat Universe.
- Publication:
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arXiv e-prints
- Pub Date:
- June 2024
- DOI:
- 10.48550/arXiv.2406.06389
- arXiv:
- arXiv:2406.06389
- Bibcode:
- 2024arXiv240606389C
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- Redshift dependent cosmological parameters in DES 5YR SNe