Constraints on Redshift-Binned Dark Energy using DESI BAO Data
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arXiv
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| Natura: | Preprint |
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2024
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| author | Pang, Ye-Huang Zhang, Xue Huang, Qing-Guo |
| author_facet | Pang, Ye-Huang Zhang, Xue Huang, Qing-Guo |
| contents | We parameterize the equation of state of late-time dark energy as $w_{\mathrm{bin}}(z)$, with three redshift bins, characterized by a constant equation of state in each bin. Then, we constrain the parameters of the $w_{\mathrm{bin}}$CDM model using datasets from DESI BAO data, Planck CMB power spectrum, ACT DR6 lensing power spectrum, and type Ia supernova distance-redshift data of Pantheon Plus/DES Y5/Union3. The significances for $w_1>-1$ is $1.9σ$, $2.6σ$ and $3.3σ$, and $w_2$ is consistent with $-1$ within $1σ$ level, while $1.6σ$, $1.5σ$ and $1.5σ$ for $w_3<-1$ in these three data combinations with different choices of type Ia supernova datasets, respectively. Additionally, to alleviate $H_0$ tension, we incorporate the early dark energy (EDE) model in the early-time universe and add the SH0ES absolute magnitude $M_b$ prior (or $H_0$ prior) to further constrain the $w_{\mathrm{bin}}$EDE model. In the $w_{\mathrm{bin}}$EDE model, we find a $w_{\mathrm{bin}}(z)$ pattern similar to that in the $w_{\mathrm{bin}}$CDM model. The results of the three data combinations exhibit $w_1>-1$ at $1.9σ$, $1.7σ$ and $2.9σ$ level, meanwhile $w_3<-1$ at $1.3σ$, $1.3σ$ and $1.3σ$ level, respectively. In all, our results indicate that the transition of dark energy from phantom at high redshifts to quintessence at low redshifts is not conclusive. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_14787 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Constraints on Redshift-Binned Dark Energy using DESI BAO Data Pang, Ye-Huang Zhang, Xue Huang, Qing-Guo Cosmology and Nongalactic Astrophysics We parameterize the equation of state of late-time dark energy as $w_{\mathrm{bin}}(z)$, with three redshift bins, characterized by a constant equation of state in each bin. Then, we constrain the parameters of the $w_{\mathrm{bin}}$CDM model using datasets from DESI BAO data, Planck CMB power spectrum, ACT DR6 lensing power spectrum, and type Ia supernova distance-redshift data of Pantheon Plus/DES Y5/Union3. The significances for $w_1>-1$ is $1.9σ$, $2.6σ$ and $3.3σ$, and $w_2$ is consistent with $-1$ within $1σ$ level, while $1.6σ$, $1.5σ$ and $1.5σ$ for $w_3<-1$ in these three data combinations with different choices of type Ia supernova datasets, respectively. Additionally, to alleviate $H_0$ tension, we incorporate the early dark energy (EDE) model in the early-time universe and add the SH0ES absolute magnitude $M_b$ prior (or $H_0$ prior) to further constrain the $w_{\mathrm{bin}}$EDE model. In the $w_{\mathrm{bin}}$EDE model, we find a $w_{\mathrm{bin}}(z)$ pattern similar to that in the $w_{\mathrm{bin}}$CDM model. The results of the three data combinations exhibit $w_1>-1$ at $1.9σ$, $1.7σ$ and $2.9σ$ level, meanwhile $w_3<-1$ at $1.3σ$, $1.3σ$ and $1.3σ$ level, respectively. In all, our results indicate that the transition of dark energy from phantom at high redshifts to quintessence at low redshifts is not conclusive. |
| title | Constraints on Redshift-Binned Dark Energy using DESI BAO Data |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2408.14787 |