Observational constraints on FLRW, Bianchi type I and V brane models
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| Format: | Preprint |
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2024
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| author | Jalalzadeh, R. Jalalzadeh, S. Malekolkalami, B. Davari, Z. |
| author_facet | Jalalzadeh, R. Jalalzadeh, S. Malekolkalami, B. Davari, Z. |
| contents | This study explores the compatibility of Covariant Extrinsic Gravity (CEG) with current cosmological observations. We employ the chi-square statistic and Markov Chain Monte Carlo (MCMC) methods to fit the FLRW and Bianchi type-I and V brane models to the latest datasets, including Hubble, Pantheon+ Supernova samples, Big Bang Nucleosynthesis (BBN), Baryon Acoustic Oscillations (BAO), and the structure growth rate, $fσ_8(z)$. Parameters for FLRW universe consist $\left(Ω^{\text{(b)}}_0, Ω^{\text{(cd)}}_0, Ω^{\text{(k)}}_0, H_0, γ, σ_8\right)$, while for the Bianchi model are $\left(Ω^{\text{(b)}}_0, Ω^{\text{(cd)}}_0, Ω^{(β)}_0, H_0, γ, Ω^{(θ)}_0, σ_8\right)$. We determine the best values for cosmological parameters. For the FLRW model, these values depend on the sign of $γ$: $γ> 0$ yields $γ=0.00008^{+0.00015}_{-0.00011}$, and $Ω^{\text{(k)}}_0=0.014^{+0.024}_{-0.022}$ and $γ< 0$ leads to $γ=-0.0226^{+0.0054}_{-0.0062}$, and $Ω^{\text{(k)}}_0=0.023^{+0.039}_{-0.041}$. In both cases $Ω^{\text{(k)}}_0>0$ represents a closed universe. Similarly, for the Bianchi type-V brane model, the parameter values vary with the sign of $γ$, resulting in $γ= 0.00084^{+0.00019}_{-0.00021}$, $Ω^{(β)}_0 =0.0258^{+0.0052}_{-0.0063} $, and $Ω^θ_0(\times 10^{-5} ) = 4.19^{+0.67}_{-0.75}$ (as with the density parameter of stiff matter) for $γ> 0$, and $γ= -0.00107^{+0.00019}_{-0.00020}$, $Ω^{(β)}_0 = 0.0259^{+0.0050}_{-0.0062} $, and $Ω^θ_0(\times 10^{-5} ) = 4.17^{+0.91}_{-0.98}$ for $γ< 0$. In both cases $Ω^{(β)}_0>0$, which represents the Bianchi type-V, because in the Bianchi type-I, $β=0$. Utilizing these obtained best values, we analyze the behavior of key cosmological parameters. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2407_15565 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Observational constraints on FLRW, Bianchi type I and V brane models Jalalzadeh, R. Jalalzadeh, S. Malekolkalami, B. Davari, Z. General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics This study explores the compatibility of Covariant Extrinsic Gravity (CEG) with current cosmological observations. We employ the chi-square statistic and Markov Chain Monte Carlo (MCMC) methods to fit the FLRW and Bianchi type-I and V brane models to the latest datasets, including Hubble, Pantheon+ Supernova samples, Big Bang Nucleosynthesis (BBN), Baryon Acoustic Oscillations (BAO), and the structure growth rate, $fσ_8(z)$. Parameters for FLRW universe consist $\left(Ω^{\text{(b)}}_0, Ω^{\text{(cd)}}_0, Ω^{\text{(k)}}_0, H_0, γ, σ_8\right)$, while for the Bianchi model are $\left(Ω^{\text{(b)}}_0, Ω^{\text{(cd)}}_0, Ω^{(β)}_0, H_0, γ, Ω^{(θ)}_0, σ_8\right)$. We determine the best values for cosmological parameters. For the FLRW model, these values depend on the sign of $γ$: $γ> 0$ yields $γ=0.00008^{+0.00015}_{-0.00011}$, and $Ω^{\text{(k)}}_0=0.014^{+0.024}_{-0.022}$ and $γ< 0$ leads to $γ=-0.0226^{+0.0054}_{-0.0062}$, and $Ω^{\text{(k)}}_0=0.023^{+0.039}_{-0.041}$. In both cases $Ω^{\text{(k)}}_0>0$ represents a closed universe. Similarly, for the Bianchi type-V brane model, the parameter values vary with the sign of $γ$, resulting in $γ= 0.00084^{+0.00019}_{-0.00021}$, $Ω^{(β)}_0 =0.0258^{+0.0052}_{-0.0063} $, and $Ω^θ_0(\times 10^{-5} ) = 4.19^{+0.67}_{-0.75}$ (as with the density parameter of stiff matter) for $γ> 0$, and $γ= -0.00107^{+0.00019}_{-0.00020}$, $Ω^{(β)}_0 = 0.0259^{+0.0050}_{-0.0062} $, and $Ω^θ_0(\times 10^{-5} ) = 4.17^{+0.91}_{-0.98}$ for $γ< 0$. In both cases $Ω^{(β)}_0>0$, which represents the Bianchi type-V, because in the Bianchi type-I, $β=0$. Utilizing these obtained best values, we analyze the behavior of key cosmological parameters. |
| title | Observational constraints on FLRW, Bianchi type I and V brane models |
| topic | General Relativity and Quantum Cosmology Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2407.15565 |