Extending Λcdm Cosmology In Presence Of Curvature And Anisotropy: A Model Comparison

Abstract

In this work, we present observational constraints on the most anisotropic extensions of the standard ΛCDM model namely ΛCDM+, ΛCDM++,  wCDM++ based on observational data such as SH0ES Cepheid host distance anchors, Big Bang Nucleosynthesis (BBN), Pantheon Plus (PP) compilation of Supernovae Type Ia (SNe Ia), Baryon Acoustic Oscillations (BAO), and Cosmic Chronometers (CC). In every analysis, the top bounds on the anisotropy are around 10⁻¹³ at 95% CL. In every instance including both data combinations, the quintessence behavior of dark energy is preferred at 68% CL. H₀ = 72.25 ± 0.84 km s⁻¹ Mpc⁻¹ in the wCDM++ model and H₀ = 72.48 ± 0.89 km s⁻¹ Mpc⁻¹ in the ΛCDM++ model, both at 68% CL, are the highest values of the Hubble constant found in the analysis.

Keywords: dark energy, cosmological constant, curvature, anisotropy

In this work, we present observational constraints on the most anisotropic extensions of the standard ΛCDM model namely ΛCDM+, ΛCDM++,  wCDM++ based on observational data such as SH0ES Cepheid host distance anchors, Big Bang Nucleosynthesis (BBN), Pantheon Plus (PP) compilation of Supernovae Type Ia (SNe Ia), Baryon Acoustic Oscillations (BAO), and Cosmic Chronometers (CC). In every analysis, the top bounds on the anisotropy are around 10⁻¹³ at 95% CL. In every instance including both data combinations, the quintessence behavior of dark energy is preferred at 68% CL. H₀ = 72.25 ± 0.84 km s⁻¹ Mpc⁻¹ in the wCDM++ model and H₀ = 72.48 ± 0.89 km s⁻¹ Mpc⁻¹ in the ΛCDM++ model, both at 68% CL, are the highest values of the Hubble constant found in the analysis.