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Revisiting $Λ$CDM extensions in light of re-analyzed CMB data

Jacobo Asorey, Javier de Cruz Pérez

Abstract

In the last years with the increasing precision in cosmological observations we have been able to establish a standard model of cosmology, the so-called $Λ$CDM, but also find some tensions between cosmological probes that are difficult to explain within the context of this model. We tested several phenomenological extensions of the $Λ$CDM with the newest datasets from the chain CMB+BAO+SNIa, to see whether they are able to alleviate the aforementioned tensions. We find that when the updated version of the Planck CMB likelihood (PR4 \texttt{LoLLiPoP} and \texttt{HiLLiPoP}), with respect to the more used likelihoods (PR4 \texttt{CamSpec} and PR3), is considered, the lensing anomaly is reduced, and the preference for $A_L>1$ and $Ω_k<0$ is less significant. From the CMB+BAO+SNIa dataset, in the context of the parameterization $w_0w_a$CDM, we find a preference for a time-evoling dark energy over the rigid cosmological constant which is consistent with the most recent results from DESI collaboration.

Revisiting $Λ$CDM extensions in light of re-analyzed CMB data

Abstract

In the last years with the increasing precision in cosmological observations we have been able to establish a standard model of cosmology, the so-called CDM, but also find some tensions between cosmological probes that are difficult to explain within the context of this model. We tested several phenomenological extensions of the CDM with the newest datasets from the chain CMB+BAO+SNIa, to see whether they are able to alleviate the aforementioned tensions. We find that when the updated version of the Planck CMB likelihood (PR4 \texttt{LoLLiPoP} and \texttt{HiLLiPoP}), with respect to the more used likelihoods (PR4 \texttt{CamSpec} and PR3), is considered, the lensing anomaly is reduced, and the preference for and is less significant. From the CMB+BAO+SNIa dataset, in the context of the parameterization CDM, we find a preference for a time-evoling dark energy over the rigid cosmological constant which is consistent with the most recent results from DESI collaboration.

Paper Structure

This paper contains 5 sections, 9 equations, 5 figures, 5 tables.

Table of Contents

  1. Introduction:
  2. Data
  3. Methodology
  4. Results
  5. Conclusions

Figures (5)

  • Figure 1: $\Lambda$CDM: Cosmological parameter constraints for the $\Lambda$CDM model obtained with the BAO+SNIa, PR4 and PR4+BAO+SNIa datasets. The parameter $H_0$ is expressed in km/s/Mpc units.
  • Figure 2: $\Lambda$CDM+$\Omega_k$: Cosmological parameter constraints for the $\Lambda$CDM+$\Omega_k$ model obtained with the BAO+SNIa, PR4 and PR4+BAO+SNIa datasets. The parameter $H_0$ is expressed in km/s/Mpc units. We include the dashed lines to highlight the flat Universe case ($\Omega_k=0$).
  • Figure 3: $\Lambda$CDM+$A_L$: Cosmological parameter constraints for the $\Lambda$CDM+$A_L$ model obtained with the BAO+SNIa, PR4 and PR4+BAO+SNIa datasets. The parameter $H_0$ is expressed in km/s/Mpc units. The dashed lines represent the $A_L=1$ case.
  • Figure 4: $w_0$CDM: Cosmological parameter constraints for the $w_0$CDM model obtained with the BAO+SNIa, PR4 and PR4+BAO+SNIa datasets. The parameter $H_0$ is expressed in km/s/Mpc units. The dashed lines highlight the $\Lambda$CDM case.
  • Figure 5: $w_0w_a$CDM: Cosmological constraints for the $w_0w_a$CDM model obtained with the BAO+SNIa, PR4 and PR4+BAO+SNIa datasets. The parameter $H_0$ is expressed in km/s/Mpc units. The dashed lines in the plot are a reference to the $\Lambda$CDM case.