English

A trium test on beyond $\Lambda$CDM triggering parameters

Cosmology and Nongalactic Astrophysics 2023-09-06 v3 General Relativity and Quantum Cosmology

Abstract

We performed a Bayesian study on three beyond LCDM phenomenological triggering parameters, the growth index γ\gamma, the dark energy equation of state parameter ww and the lensing deviation from the GR prediction parameter Σ\Sigma, using the latest cosmological geometric, growth and lensing probes, all in a consistent implementation within the modified gravity cosmological solver code MGCLASS. We find, when we combined all our probes, i.e. the cosmic microwave background (CMB), the baryonic acoustic oscilation (BAO), the growth measurements fσ8f\sigma_8 and the 3×\times2pt joint analysis of weak lensing and galaxy clustering in photometric redshift surveys, assuming flat space, constraints compatible with general relativity and Λ\LambdaCDM for ω=1.025±0.045\omega = -1.025\pm0.045, and Σ=0.992±0.022\Sigma = 0.992\pm0.022 at the 68\% level, while γ=0.633±0.044\gamma = 0.633\pm0.044 is still within 2σ\sim 2 \sigma from the Λ\LambdaCDM value of γ0.55\gamma \sim 0.55, and that when Σ\Sigma is considered as constant; while γ=0.025±0.045\gamma_\ell = -0.025 \pm0.045 when the lensing parameter is parameterised as function of a lensing index, introduced for the first time in this work, as Σ(z)=Ωm(z)γ\Sigma(z)=\Omega_m(z)^{\gamma_\ell}.

Keywords

Cite

@article{arxiv.2305.02817,
  title  = {A trium test on beyond $\Lambda$CDM triggering parameters},
  author = {Ziad Sakr},
  journal= {arXiv preprint arXiv:2305.02817},
  year   = {2023}
}

Comments

Matches the accepted version after a proof reading and minor changes

R2 v1 2026-06-28T10:25:39.268Z