Updated Cosmological Constraints in Extended Parameter Space with Planck PR4, DESI Baryon Acoustic Oscillations, and Supernovae: Dynamical Dark Energy, Neutrino Masses, Lensing Anomaly, and the Hubble Tension

TL;DR

This study updates cosmological constraints using Planck PR4, DESI BAO, and supernova data in an extended 12-parameter model, examining dark energy, neutrino masses, lensing, and the Hubble tension, with mixed results on key tensions and parameters.

Contribution

It provides the first comprehensive analysis of an extended cosmological model with multiple datasets, highlighting the robustness and limitations of current constraints.

Findings

CMB+BAO+Pantheon+ data include a cosmological constant within 2σ.

Some data combinations show a 1σ+ detection of non-zero neutrino masses.

The Hubble tension remains at 3.2-3.9σ, not resolved by extensions.

Abstract

We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter $\Lambda$CDM by including dynamical dark energy (DE: $w_0$, $w_a$), the sum of neutrino masses ($\sum m_{\nu}$), the effective number of non-photon radiation species ($N_{\rm eff}$), the lensing amplitude scaling ($A_{\rm lens}$), and the running of the scalar spectral index ($\alpha_s$). For CMB data, we use the Planck PR4 (2020) HiLLiPoP and LoLLiPoP likelihoods, Planck PR4+ACT DR6 lensing, and Planck 2018 low-$l$ TT likelihoods, along with DESI DR1 BAO and Pantheon+ and DESY5 uncalibrated type Ia Supernovae (SNe) likelihoods. Key findings are the following: i) Contrary to DESI results, CMB+BAO+Pantheon+ data include a cosmological constant within $2\sigma$, while CMB+BAO+DESY5 excludes it at over $2\sigma$, indicating the dynamical nature of dark energy is not yet robust. Potential systematics in the DESY5 sample may drive this exclusion. ii) Some data combinations show a $1\sigma$+ detection of non-zero $\sum m_{\nu}$, indicating possible future detection. We also provide a robust upper bound of $\sum m_{\nu} \lesssim 0.3$ eV (95% confidence limit (C.L.)). iii) With CMB+BAO+SNe, $A_{\rm lens} = 1$ is included at $2\sigma$ (albeit not at $1\sigma$), indicating no significant lensing anomaly in this extended cosmology with Planck PR4 likelihoods. iv) The Hubble tension persists at $3.2$ to $3.9\sigma$, suggesting these simple extensions do not resolve it. v) The $S_8$ tension with DES Year 3 weak lensing is reduced to $1.4\sigma$, likely due to additional parameters and the Planck PR4 likelihoods.