How robust are the parameter constraints extending the $\Lambda$CDM model?

Abstract

We present model-marginalized limits on the six standard $\Lambda$CDM cosmological parameters (${\Omega }_{\mathrm{c}}{h}^2$, ${\Omega }_{\mathrm{b}}{h}^2$, ${\theta }_{\mathrm{MC}}$, ${\tau }_{\mathrm{reio}}$, $n_s$ and $A_s$), as well as on selected derived quantities ($H_0$, ${\Omega }_{\mathrm{m}}$, ${\sigma }_8$, $S_8$ and $r_{\mathrm{drag}}$), obtained by considering several extensions of the $\Lambda$CDM model and three independent Cosmic Microwave Background (CMB) experiments: the Planck satellite, the Atacama Cosmology Telescope, and South Pole Telescope. We also consider low redshift observations in the form of Baryon Acoustic Oscillation (BAO) data from the SDSS-IV eBOSS survey and Supernovae (SN) distance moduli measurements from the \textit{Pantheon-Plus} catalog. The marginalized errors are stable against the different minimal extensions of the $\Lambda$CDM model explored in this study. The largest impact on the parameter accuracy is produced by varying the effective number of relativistic degrees of freedom ($N_{\mathrm{eff}}$) or the lensing amplitude ($A_{\mathrm{lens}}$). Nevertheless, the marginalized errors on some \textit{derived} parameters such as $H_0$ or ${\Omega }_{\mathrm{m}}$ can be up to two orders of magnitude larger than in the canonical $\Lambda$CDM scenario when considering only CMB data. In these cases, low redshift measurements are crucial for restoring the stability of the marginalized cosmological errors computed here. Overall, our results underscore remarkable stability in the mean values and precision of the main cosmological parameters once both high and low redshift probes are fully accounted for. The marginalized values can be used in numerical analyses due to their robustness and slightly larger errors, providing a more realistic and conservative approach.

arXiv comment24 pages, 11 figures, 11 tables. Version accepted for publication in PRD

References in corpus (48)

• Cosmological parameters from CMB and other data: a Monte-Carlo approach
• Exploring the Expansion History of the Universe
• Accelerating Universes with Scaling Dark Matter
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• The Pantheon+ Analysis: Cosmological Constraints
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Planck 2018 results. V. CMB power spectra and likelihoods
• The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
• Planck 2018 results. VIII. Gravitational lensing
• Cobaya: Code for Bayesian Analysis of hierarchical physical models
• The Atacama Cosmology Telescope: DR4 Maps and Cosmological Parameters
• Planck evidence for a closed Universe and a possible crisis for cosmology
• PolyChord: nested sampling for cosmology
• PolyChord: next-generation nested sampling
• Curvature tension: evidence for a closed universe
• Reconciling Planck with the local value of $H_0$ in extended parameter space
• The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
• How Massless Neutrinos Affect the Cosmic Microwave Background Damping Tail
• The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and its Implications for Structure Growth
• Cosmic Microwave Weak lensing data as a test for the dark universe
• CMB power spectra and cosmological parameters from Planck PR4 with CamSpec
• Cosmological parameters derived from the final (PR4) Planck data release
• No evidence for extensions to the standard cosmological model
• Efficient Cosmological Parameter Estimation from Microwave Background Anisotropies
• Investigating Cosmic Discordance
• Cosmological constraints in extended parameter space from the Planck 2018 Legacy release
• A Detailed Description of the CamSpec Likelihood Pipeline and a Reanalysis of the Planck High Frequency Maps
• PArthENoPE reloaded
• On the most constraining cosmological neutrino mass bounds
• Quantifying the global parameter tensions between ACT, SPT and Planck
• The state of the dark energy equation of state circa 2023
• Revealing the effects of curvature on the cosmological models
• Health checkup test of the standard cosmological model in view of recent Cosmic Microwave Background Anisotropies experiments
• Cosmological constraints on slow-roll inflation: an update
• Is the Harrison-Zel'dovich spectrum coming back? ACT preference for $n_s\sim 1$ and its discordance with Planck
• Inflation, the Hubble Tension and Early Dark Energy: an alternative overview
• A Bayesian interpretation of inconsistency measures in cosmology
• Quantifying the global "CMB tension" between the Atacama Cosmology Telescope and the Planck satellite in extended models of cosmology
• Beyond $\Lambda$CDM constraints from the full shape clustering measurements from BOSS and eBOSS
• Model marginalized constraints on neutrino properties from cosmology
• Measuring the reionization optical depth without large-scale CMB polarization
• Inflationary Potential as seen from Different Angles: Model Compatibility from Multiple CMB Missions
• What is flat ΛCDM, and may we choose it?
• On the consistency of $\Lambda$CDM with CMB measurements in light of the latest Planck, ACT, and SPT data
• Cosmology-marginalized approaches in Bayesian model comparison: the neutrino mass as a case study
• A novel model-marginalized cosmological bound on the QCD axion mass
• Impact of the damping tail on neutrino mass constraints

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