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arXiv 1209.2619gr-qcastro-ph.CO
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具有非最小耦合的f(R)模型的奇异性问题

Singularity problem in f(R) model with non-minimal coupling

Qiang Xu, Sheng-yu Tan

摘要:

在f(R)理论中考虑了物质与几何之间的非最小耦合。在我们建立的新理论中,定义了一个新的标量$ψ$,并给出了它的稳定性条件。我们打算仔细研究de-Sitter宇宙和物质时代中的暗能量振荡行为,从中我们推导出振荡频率和振荡条件。更重要的是,给出了奇异性可解的耦合形式条件。讨论了几种具体的耦合形式,发现在物质时代$z>4$,具有振荡周期$ΔT\simΔz$的对数耦合可以改善早期宇宙的奇异性。数值计算结果验证了理论计算的正确性。考虑两个玩具模型,我们发现当$lna>4$ .我们还讨论了非最小耦合f(R)模型的局部检验,并给出了对耦合形式的约束。

英文摘要:

We consider the non-minimal coupling between matter and the geometry in the f(R) theory. In the new theory which we established, a new scalar $ψ$ has been defined and we give it a certain stability condition. We intend to take a closer look at the dark energy oscillating behavior in the de-Sitter universe and the matter era, from which we derive the oscillating frequency, and the oscillating condition. More importantly, we present the condition of coupling form that the singularity can be solved. We discuss several specific coupling forms, and find logarithmic coupling with an oscillating period $ΔT\simΔz$ in the matter era $z>4$, can improve singularity in the early universe. The result of numerical calculation verifies our theoretic calculation about the oscillating frequency. Considering two toy models, we find the cosmic evolution in the coupling model is nearly the same as that in the normal f(R) theory when $lna>4$. We also discuss the local tests of the non-minimal coupling f(R) model, and show the constraint on the coupling form.

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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