Anisotropic evolution of 4-brane in a 6D generalized Randall-Sundrum model
Anisotropic evolution of 4-brane in a 6D generalized Randall-Sundrum model
复制标题
6D 广义 Randall-Sundrum 模型中 4 膜的各向异性演化
DOI：
10.1088/1674-1137/43/9/095101
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发表时间：
2019
影响因子：
3.6
通讯作者：
Zong Hong-Shi
中科院分区：
文献类型：
--
作者：
Kang Guang-Zhen;Zhang De-Sheng;Du Long;Xu Jun;Zong Hong-Shi
我们研究了具有体宇宙学常数的 6d 广义 Randall-Sundrum 膜世界场景。结果表明，膜上的每个应力能量张量 $T_{ab}^{i}$ 类似于恒定的真空能量。这与 Randall-Sundrum 模型一致，其中每个 3 膜拉格朗日分离出恒定的真空能量。通过采用各向异性度量 ansatz，我们得到了 5d Friedmann-Robertson-Walker 场方程。在稍后的时期，宇宙的膨胀与 $t^{\frac{1}{2}}$ 成正比，这与辐射主导的周期相似。我们还调查了两个 $a(t)$ 和两个 $b(t)$ 的情况。在$t$的大范围内，我们得到与积分常数无关的3d有效宇宙常数$\Lambda_{eff}=-2\Omega/3>0$。这里的比例因子是指数膨胀，这与我们目前对宇宙的观测是一致的。我们的结果表明，可以构建一个解决暗能量问题的模型，同时保证正的膜张力。
We investigate a 6d generalized Randall-Sundrum brane world scenario with a bulk cosmological constant. It is shown that each stress-energy tensor $T_{ab}^{i}$ on the brane is similar to a constant vacuum energy. This is consistent with the Randall-Sundrum model in which each 3-brane Lagrangian separated out a constant vacuum energy. By adopting an anisotropic metric ansatz, we obtain the 5d Friedmann-Robertson-Walker field equations. At a little later period, the expansion of the universe is proportional to $t^{\frac{1}{2}}$ which is as similar as the period of the radiation-dominated. We also investigate the case with two $a(t)$ and two $b(t)$. In a large region of $t$, we obtain the 3d effective cosmological constant $\Lambda_{eff}=-2\Omega/3>0$ which is independent of the integral constant. Here the scale factor is exponential expansion which is consistent with our present observation of the universe. Our results demonstrate that it is possible to construct a model which solves the dark energy problem, meanwhile guaranteeing a positive brane tension.