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arXiv 0705.2443gr-qcastro-phhep-th
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任意维数的无Z_2对称的膜世界

A Brane World in an Arbitrary Number of Dimensions without Z_2 Symmetry

Daisuke Yamauchi, Misao Sasaki

摘要:

考虑任意维数的无Z_2对称的膜世界,导出膜上的有效爱因斯坦方程,其右端由膜上的物质和体的曲率给出.这是通过首先导出非Z2对称膜的结条件,然后求解Gauss方程来实现的,Gauss方程将膜的平均外曲率与体曲率联系起来,并关于平均外曲率。后者对应于制定一个明确的交界处条件的平均值的非本征曲率,类似于以色列交界处条件的跳跃的非本征曲率。我们发现,由于不存在Z_2对称性,在有效爱因斯坦方程的右侧出现了一种新的有效各向异性流体。导出的方程是研究Kaluza-Klein膜世界的基本方程,在Kaluza-Klein膜世界中,膜上的某些维是紧化的,或者是高余维膜世界的正则化方案,其中膜上的Kaluza-Klein紧化被认为是正则化由高余维膜引起的不可控时空奇异性的一种手段.

英文摘要:

We consider a brane world in an arbitrary number of dimensions without Z_2 symmetry and derive the effective Einstein equation on the brane, where its right-hand side is given by the matter on the brane and the curvature in the bulk. This is achieved by first deriving the junction conditions for a non-Z_2 symmetric brane and second solving the Gauss equation, which relates the mean extrinsic curvature of the brane to the curvature in the bulk, with respect to the mean extrinsic curvature. The latter corresponds to formulating an explicit junction condition on the mean of the extrinsic curvature, analogue to the Israel junction condition for the jump of the extrinsic curvature. We find that there appears a new type of an effective anisotropic fluid on the right-hand side of the effective Einstein equation due to the fact that there is no Z_2 symmetry. The derived equation is a basic equation for the study of Kaluza-Klein brane worlds in which some dimensions on the brane are compactified or for a regularization scheme for a higher codimension brane world, where the Kaluza-Klein compactification on the brane is regarded as a means to regularize the uncontrollable spacetime singularity caused by the higher codimension brane.

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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