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arXiv 1702.05786gr-qcastro-ph.COhep-phhep-th
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时空奇点的一般相图分析与广义遥平行引力

Generic Phase Portrait Analysis of the Finite-time Singularities and Generalized Teleparallel Gravity

W. El Hanafy, G. G. L. Nashed

摘要:

我们分析了常见的四种类型的有限时间奇点使用一个通用的框架的相图几何方法。这种技术要求弗里德曼系统被写成一维自治系统。我们采用了一个比例因子,已被广泛使用的文献中实现的四个有限时间奇点类型,然后我们显示了详细的讨论,为每种情况下显示可能的新模型。此外,我们展示了不同的奇点类型如何在不同的宇宙学场景中发挥重要作用。在几个修改的引力理论,我们表明,f(T)宇宙学是舒适的相图分析,因为场方程包括哈勃导数只有到一阶。因此,我们重建了生成这些相图的f(T)理论。我们还使用有效状态方程进行了补充分析。此外,我们还研究了扭转流体在实现宇宙奇点中的作用。

英文摘要:

We analyze the common four types of the finite-time singularities using a generic framework of the phase portrait geometric approach. This technique requires that the Friedmann system to be written as a one dimensional autonomous system. We employ a scale factor that has been used widely in literature to realize the four finite-time singularity types, then we show a detailed discussion for each case showing possible novel models. Moreover, we show how different singularity types can play essential roles in different cosmological scenarios. Among several modified gravity theories, we show that the f (T) cosmology is in comfort with the phase portrait analysis, since the field equations include Hubble derivatives only up to first order. Therefore, we reconstruct the f (T) theory which generates these phase portraits. We also perform a complementary analysis using the effective equation of state. Furthermore, we investigate the role of the torsion fluid in realizing the cosmic singularities.

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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