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Constraining Bianchi type I universe with type Ia supernova and H(z) data
Physics of the Dark Universe ( IF 5.5 ) Pub Date : 2020-04-20 , DOI: 10.1016/j.dark.2020.100557
Hassan Amirhashchi , Soroush Amirhashchi

We use recent 36 observational Hubble data (OHD) in the redshift range 0.07z2.36, latest “joint light curves” (JLA) sample, comprised of 740 type Ia supernovae (SNIa) in the redshift range 0.01z1.30, and their joint combination datasets to constrain anisotropic Bianchi type I (BI) dark energy (DE) model. To estimate model parameters, we apply Hamiltonian Monte Carlo technique. We also compute the covariance matrix for BI dark energy model by considering different datasets to compare the correlation between model parameters. To check the acceptability of our fittings, all results are compared with those obtained from 9 year WMAP as well as Planck (2015) collaboration. Our estimations show that at 68% confidence level the dark energy equation of state (EOS) parameter for OHD or JLA datasets alone varies between quintessence and phantom regions whereas for OHD+JLA dataset this parameter only varies in phantom region. It is also found that the current cosmic anisotropy is of order 103 which imply that the OHD and JLA datasets do not put tight constraint on this parameter. Therefore, to constraint anisotropy parameter, it is necessary to use high redshift dataset namely cosmic microwave background (CMB). Moreover, from the calculation of p-value associated with χ2 statistic we observed that non of the ωBI and flat ωCDM models rule out by OHD or JLA datasets. The deceleration parameter is obtained as q=0.460.410.37+0.89+0.36, q=0.6190.0950.24+0.12+0.20, and q=0.520.0460.15+0.080+0.014 for OHD, SNIa, and OHD+SNIa data respectively.



中文翻译:

用Ia型超新星和H(z)数据约束Bianchi I型宇宙

我们使用红移范围内的最近36个哈勃观测数据(OHD) 007ž236,最新的“联合光曲线”(JLA)样本,由红移范围内的740型Ia超新星(SNIa)组成 001ž1个30,以及它们的联合组合数据集来约束各向异性Bianchi I型(BI)暗能量(DE)模型。为了估计模型参数,我们应用哈密顿蒙特卡罗技术。我们还通过考虑不同的数据集来比较模型参数之间的相关性,从而为BI暗能量模型计算协方差矩阵。为了检查我们配件的可接受性,将所有结果与从9年WMAP以及Planck(2015)合作获得的结果进行比较。我们的估计表明,在68%置信水平下,仅OHD或JLA数据集的暗能量状态方程(EOS)参数在典型区域和幻像区域之间变化,而对于OHD + JLA数据集,此参数仅在幻像区域变化。还发现当前的宇宙各向异性是有序的1个0-3这意味着OHD和JLA数据集没有对该参数施加严格的约束。因此,要约束各向异性参数,必须使用高红移数据集,即宇宙微波背景(CMB)。而且,从计算p值与 χ2 统计数据我们观察到 ω 和平 ω清洁发展机制模型被OHD或JLA数据集排除。减速参数为q=-046-041-037+089+036q=-0619-0095-024+012+020q=-052-0046-015+0080+0014 分别用于OHD,SNIa和OHD + SNIa数据。

更新日期:2020-04-20
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