论文标题
Bianchi I型宇宙模型具有自定义量表因子
Bianchi Type I model of universe with customized scale factors
论文作者
论文摘要
根据标准宇宙学，宇宙在大尺度上是均匀的和各向同性的。但是，可以通过各种方式在宇宙的本地规模上观察到一些各向异性。在这里，我们研究了Bianchi I型模型，并通过自定义规模因素来了解宇宙的各向异性性质。我们考虑了两种情况，在广义Bianchi I型度量方程中，在不同方向上对比例因子进行了轻微的修改，并将结果与$λ$ CDM模型以及可用的宇宙学观察数据进行了比较。通过这项研究，我们还希望通过计算低红移（z）的各向异性参数（$ω_σ$）以及可能存在的不同方向之间可能存在的相对各向异性的可能性，以预测早期宇宙中存在的各向异性程度及其到当前时间的演变。发现早期宇宙中有大量各向异性，并且宇宙的各向异性在近乎过去和当前时期都消失了。因此，在宇宙的几乎过去和现在阶段，这种各向异性模型与标准$λ$ CDM模型之间没有有效的区别。
According to standard cosmology, the universe is homogeneous and isotropic at large scales. However, some anisotropies can be observed at the local scale in the universe through various ways. Here we have studied the Bianchi type I model with customizing the scale factors to understand the anisotropic nature of the universe. We have considered two cases with slight modifications of scale factors in different directions in the generalized Bianchi Type I metric equation, and compared the results with the $Λ$CDM model and also with available cosmological observational data. Through this study, we also want to predict the possible degree of anisotropy present in the early universe and its evolution to current time by calculating the value of density parameter for anisotropy ($Ω_σ$) for both low and high redshift (z) along with the possible relative anisotropy that exist among different directions. It is found that there was a significant amount of anisotropy in the early universe and the anisotropic nature of the universe vanishes at the near past and the present epochs. Thus at near past and present stages of the universe there is no effective distinction between this anisotropic model and the standard $Λ$CDM model.
