标题： 各向异性LRS-BI宇宙与$f(Q)$引力理论 显示英文标题

标题： Anisotropic LRS-BI Universe with $f(Q)$ gravity theory

摘要： 宇宙早期阶段可能的各向异性是宇宙学研究中的一个有趣方面。 我们考虑在对称的全等平行理论等价于广义相对论（STEGR）的$f(Q)$引力下，以少量宇宙学参数研究宇宙的演化，该模型采用各向异性局部旋转对称（LRS） Bianchi类型-I时空（LRS-BI）。 在本研究中，我们考虑两种$f(Q)$引力模型，即$f(Q) = -\,(Q+2\Lambda)$，一个包含宇宙常数$\Lambda$的简单模型和幂律模型$f(Q) = -\, \alpha Q^n$，该模型包含两个常数参数$\alpha$和$n$。 考虑方向哈勃参数之间的比例关系，比例常数参数为$\lambda$，我们发现各向异性因子在早期宇宙演化中对两种模型都有显著贡献。 幂律模型显示，与简单模型相比，各向异性的影响更为显著，这取决于模型参数，尤其是参数$n$。 幂律模型还显示，各向异性可能对宇宙的近期演化产生一些影响。 此外，两种模型都确认，在宇宙的当前阶段，各向异性没有获得任何可察觉的特征。 从我们的分析中，我们还设定了模型参数的大致约束，分别为$0.5 \le \lambda \le 1.25$、$0.75 \le \alpha \le 1.5$和$0.95 \le n \le 1.05$。 显示英文摘要

摘要： The possible anisotropic nature in the early phases of the Universe is one of the interesting aspects of study in cosmology. We investigate the evolution of the Universe in terms of few cosmological parameters considering an anisotropic locally rotationally symmetric (LRS) Bianchi type-I spacetime (LRS-BI) under the $f(Q)$ gravity of symmetric teleparallel theory equivalent to the GR (STEGR). In this study we consider two $f(Q)$ gravity models, viz., $f(Q) = -\,(Q+2\Lambda)$, a simple model with the cosmological constant $\Lambda$ and the power law model, $f(Q) = -\, \alpha Q^n$ with two constant parameters $\alpha$ and $n$. Considering a proportionality relation between the directional Hubble parameters with a proportionality constant parameter $\lambda$ we find a significant contribution of the anisotropic factor in the evolution of the early Universe for both models. The power law model shows the more dominating effect of anisotropy in comparison to the simple model depending on model parameters, especially on the parameter $n$. The power law model also shows some possible effects of anisotropy on the Universe's evolution in the near future. In addition, both models confirm that the anisotropy does not obtain any appreciable signature in the current stage of the Universe. From our analysis we also set rough constraints on our model parameters as $0.5 \le \lambda \le 1.25$, $0.75 \le \alpha \le 1.5$ and $0.95 \le n \le 1.05$.