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arXiv 2008.03562gr-qc
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高维动力学虫洞与涌现宇宙

Dynamical Wormholes in Higher Dimensions and the Emergent Universe

B. C. Paul

摘要:

提出了一种新的高维动力学虫洞模型,该模型支持平坦突现宇宙(EU)模型。欧盟模型是免费的初始奇点与其他观测到的宇宙特征。EU模型的基本假设是,当前的宇宙是从一个静态的爱因斯坦宇宙演化而来的。EU模型起源于一个动力学的虫洞,它的咽喉是爱因斯坦静态宇宙的种子。提出了高维平坦宇宙中的一类宇宙学解。确定了封闭宇宙的一个新的形函数。非线性状态方程(EoS)对应于三种类型的宇宙流体。EoS参数决定了宇宙流体。时空维度决定了特定流体的变化率,该变化率随具有非相互作用流体的动态演化宇宙的比例因子而变化。考虑到时间$t > t_0$上的相互作用,在这三种流体中,有可能令人满意地描述观测到的宇宙。在高维宇宙中,发现在喉附近零能条件(NEC)被违反,但远离喉NEC被发现服从承认观察到的宇宙的一个平坦的情况。欧盟模式的另一个有趣的方面是,它允许后期加速阶段。然而,在渐近封闭或开放的宇宙中,平坦突现宇宙可以容纳NEC,它从喉咙到现在的时代一直遵守。本文估计了虫洞喉部的张力,发现它依赖于爱因斯坦静态宇宙的初始大小和宇宙的维数。有趣的是,NEC并没有被违反,以适应封闭或开放宇宙的动力学虫洞。虽然在平坦宇宙的咽喉处需要奇异物质,但在包含涌现宇宙的封闭或开放宇宙中不需要奇异物质。

英文摘要:

Dynamical wormholes in higher dimensions which admit flat emergent universe (EU) model is presented. The EU model is free from initial singularity with other observed features of the universe. The basic assumption of EU model was that the present universe emerged out from a static Einstein universe. EU model originates from a dynamical wormhole, its throat is the seed of Einstein Static universe. A class of cosmological solutions in a higher dimensional flat universe is presented. A new shape function for closed universe is determined. The non-linear equation of state (EoS) corresponds to three types of cosmic fluids. The EoS parameters determine the cosmic fluids. The space-time dimensions determines the rate of change of a particular fluid that varies with the scale factor of a dynamically evolving universe with non-interacting fluids. Considering interaction at time $t > t_0$, among the three types of fluids it is possible to describe the observed universe satisfactorily. In a higher dimensional universe it is found that near the throat null energy condition (NEC) is violated, but away from the throat NEC is found to obey admitting the observed universe for a flat case. Another interesting aspect of the EU model is that it permits late accelerating phase. However, in asymptotic closed or open universe, flat emergent universe can be accommodated with NEC which is obeyed right from the throat to the present epoch. The tension at the throat of the wormhole is estimated which is found to depend on the initial size of the Einstein static universe and dimensions of the universe. It is interesting to note that NEC is not violated to accommodate dynamical wormholes for closed or open universe. Although exotic matter is required at the throat for the flat universe, no exotic matter is required for closed or open universe which encompass the emergent universe.

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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