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arXiv 0901.0835gr-qc
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高维物质的5D Kaluza-Klein宇宙学中的4D膨胀宇宙

An expanding 4D universe in a 5D Kaluza-Klein cosmology with higher dimensional matter

F. Darabi

摘要:

在Kaluza-Klein理论框架下,我们研究了由$(4+1)$维能量动量张量和$(4+1)$维Robertson-Walker型度规耦合构成的$(4+1)$维宇宙.物质部分由能量密度和压强组成,压强服从$(4+1)$维能量-动量张量的4D部分。暗部分仅由暗压力$\bar{p}$组成,对应于由标量场赋予的额外维度,没有暗能量元素。结果表明,约化的爱因斯坦场方程不受四维压力的影响,只受四维能量密度和暗压产生的有效压力的影响。然后提出宇宙的膨胀可能是由更高维度的状态方程控制的,而不是四维。这可能解释了在物质主导时代中期出现的意想不到的电流加速度。

英文摘要:

In the framework of Kaluza-Klein theory, we investigate a $(4+1)$-dimensional universe consisting of a $(4+1)$ dimensional Robertson-Walker type metric coupled with a $(4+1)$ dimensional energy-momentum tensor. The matter part consists of an energy density together with a pressure subject to 4D part of the $(4+1)$ dimensional energy-momentum tensor. The dark part consists of just a dark pressure $\bar{p}$, corresponding to the extra-dimension endowed by a scalar field, with no element of dark energy. It is shown that the reduced Einstein field equations are free of 4D pressure and are just affected by an effective pressure produced by the 4D energy density and dark pressure. It is then proposed that the expansion of the universe may be controlled by the equation of state in higher dimension rather than four dimensions. This may account for the emergence of unexpected current acceleration in the middle of matter dominant era.

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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