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arXiv 0809.5226hep-thastro-phgr-qc
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关于非线性多维宇宙模型中的暴胀问题

On the problem of inflation in nonlinear multidimensional cosmological models

Tamerlan Saidov, Alexander Zhuk

摘要:

考虑一个具有非线性二次$R^2$和四次$R^4$作用量的多维宇宙模型.作为物质源,我们引入了一个量子场、D维裸宇宙学常数和位于不动点的膜的张力。根据宇宙额外维度模型的精神,标准模型的场并不局限于膜上,而是可以整体运动。我们定义的条件,确保稳定的内部空间的紧化在零最小的有效潜力。这种有效势可能具有相当复杂的形式,具有许多局部极小值、极大值和鞍点。然后,我们研究了这些模型中的通货膨胀。结果表明,$R^2$和$R^4$模型可以分别具有多达10个和22个e-折叠。这些值不足以解决均匀性和各向同性问题,但足以解释最近的CMB数据。此外,$R^4$模型还为拓扑膨胀提供了条件.然而,给出的暴胀模型的主要缺点在于光谱指数$n_s$的值小于现在观测到的$n_s\approx 1$。例如,在$R^4$模型的情况下,我们发现$n_s \approx 0.61$。

英文摘要:

We consider a multidimensional cosmological model with nonlinear quadratic $R^2$ and quartic $R^4$ actions. As a matter source, we include a monopole form field, D-dimensional bare cosmological constant and tensions of branes located in fixed points. In the spirit of the Universal Extra Dimensions models, the Standard Model fields are not localized on branes but can move in the bulk. We define conditions which ensure the stable compactification of the internal space in zero minimum of the effective potentials. Such effective potentials may have rather complicated form with a number of local minima, maxima and saddle points. Then, we investigate inflation in these models. It is shown that $R^2$ and $R^4$ models can have up to 10 and 22 e-foldings, respectively. These values are not sufficient to solve the homogeneity and isotropy problem but big enough to explain the recent CMB data. Additionally, $R^4$ model can provide conditions for eternal topological inflation. However, the main drawback of the given inflationary models consists in a value of spectral index $n_s$ which is less than observable now $n_s\approx 1$. For example, in the case of $R^4$ model we find $n_s \approx 0.61$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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