论文标题
f(q)重力的各向异性宇宙与混合膨胀
Anisotropic Universe in f(Q) gravity with Hybrid expansion
论文作者
论文摘要
尽管对加速宇宙学有着相当成功的说法,但了解宇宙的早期演变一直很困难。我们的有前途的策略是基于一种新颖的对称的对称电触电理论,称为$ f(q)$,其中重力相互作用是由非金属标量$ q $引起的,这可能有助于解决一些问题。我们考虑局部旋转对称(LRS)Bianchi型I型时空宇宙学模型,并得出了方程运动以研究宇宙的早期演变。通过假设平均量表因子的混合扩展定律(HEL),我们可以确定Bianchi型I型时空的场方程的解决方案。我们讨论了能量密度曲线,状态方程和偏度参数,并得出结论,我们的模型在宇宙早期阶段保持各向异性空间几何形状,并且可能存在各向异性流体。但是,随着时间的流逝,即使在存在各向异性流体的情况下,由于通胀,宇宙也可能朝向各向同性,而流体的各向异性同时消失。从声音的平方速度可以看出,宇宙一开始就显示出幻影性质,然后在当前时代进入黑暗能量。我们分析了派生模型的几何和物理行为。
Despite having a reasonably successful account of accelerated cosmology, understanding the early evolution of Universe has always been difficult for mankind. Our promising strategy is based on a novel class of symmetric teleparallel theories of gravity called $f(Q)$, in which the gravitational interaction is caused by the non-metricity scalar $Q$, which may help to solve some problems. We consider the locally rotationally symmetric (LRS) Bianchi type-I spacetime cosmological models and derive the motion of equations to study the early evolution of the cosmos. By assuming the Hybrid Expansion Law (HEL) for the average scale factor, we are able to determine the solutions to the field equations of Bianchi type-I spacetime. We discuss the energy density profile, the equation of state, and the skewness parameter and conclude that our models preserve anisotropic spatial geometry during the early stages of the Universe with the possibility of an anisotropic fluid present. However, as time goes on, even in the presence of an anisotropic fluid, the Universe may move towards isotropy due to inflation while the anisotropy of the fluid dims away at the same time. It is seen from the squared speed of sound that Universe shows phantom nature at the beginning then approaches to dark energy at present epoch. We analyze both geometrical and physical behaviors of the derived model.