Missing Components in ΛCDM from DESI Y1 BAO Measurements: Insights from Redshift Remapping

Abstract

We explore transformations of the Friedman-Lemaître-Robertson-Walker (FLRW) metric and cosmological parameters that align with observational data, aiming to gain insights into potential extensions of standard cosmological models. We modify the FLRW metric by introducing a scaling factor, $e^{2\Theta (a)}$ (the cosmological scaling function, CSF), which alters the standard relationship between cosmological redshift and the cosmic scale factor without affecting angular measurements or Cosmic Microwave Background (CMB) anisotropies. Using data from DESI Year 1, Pantheon+ supernovae, and the Planck CMB temperature power spectrum, we constrain both the CSF and cosmological parameters through a Markov Chain Monte Carlo approach. Our results indicate that the CSF model fits observational data with a lower Hubble constant (although it is compatible with the value given by Planck 2018 within 1$\sigma$) and is predominantly dark-matter-dominated. Additionally, the CSF model produces temperature and lensing power spectra similar to those predicted by the standard model, though with lower values in the CSF model at large scales. We have also checked that when fitting a CSF model without dark energy to the data, we obtain a more negative conformal function. This suggests that the CSF model may offer hints about missing elements and opens up a new avenue for exploring physical interpretations of cosmic acceleration.

arXiv comment16 pages, 11 figures

References in corpus (21)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Efficient Computation of CMB anisotropies in closed FRW models
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• The Cosmic Microwave Background Spectrum from the Full COBE/FIRAS Data Set
• The Pantheon+ Analysis: Cosmological Constraints
• Big Bang Nucleosynthesis: 2015
• Cobaya: Code for Bayesian Analysis of hierarchical physical models
• Cosmic Background Anisotropies in CDM Cosmology
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Interpretation of the TT and TE Angular Power Spectrum Peaks
• HD 140283: A Star in the Solar Neighborhood that Formed Shortly After the Big Bang
• The Pantheon+ Analysis: Evaluating Peculiar Velocity Corrections in Cosmological Analyses with Nearby Type Ia Supernovae
• Cosmology Intertwined IV: The Age of the Universe and its Curvature
• The local and distant Universe: stellar ages and $H_0$
• An Ultra Metal-poor Star Near the Hydrogen-burning Limit
• Conformally Friedmann-Lemaitre-Robertson-Walker cosmologies
• Back-Reaction in Relativistic Cosmology
• Testing the mapping between redshift and cosmic scale factor
• Consistent extinction model for type Ia supernovae in Cepheid-based calibration galaxies and its impact on $H_0$
• Redshift remapping and cosmic acceleration in dark-matter-dominated cosmological models