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arXiv 1202.1879gr-qcastro-ph.COhep-thmath-phmath.MP
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Weyl-Cartan-Weitzenböck引力是遥平行引力的推广

Weyl-Cartan-Weitzenböck gravity as a generalization of teleparallel gravity

Zahra Haghani, Tiberiu Harko, Hamid Reza Sepangi, Shahab Shahidi

摘要:

我们考虑Weyl-Cartan时空中的引力模型,其中也施加了曲率和挠率标量之和为零的Weitzenböck条件。此外,扭转的动力学项也包括在引力作用中。该模型的场方程是由Hilbert-Einstein型变分原理得到的,它们分别用外尔矢量和挠率这两个场来描述引力场.宇宙学应用的模型进行了调查的一个特定的选择的自由参数,其中的扭转矢量是成比例的外尔矢量。根据宇宙学模型参数的数值,可以获得多种动态演化,从暴胀/加速膨胀到非暴胀行为。特别是,我们表明,德西特型后期的时间演化可以自然地从模型的场方程。因此,目前的模型导致的可能性,一个纯粹的几何描述的暗能量,其中宇宙的后期时间加速是由内在的几何时空。

英文摘要:

We consider a gravitational model in a Weyl-Cartan space-time, in which the Weitzenböck condition of the vanishing of the sum of the curvature and torsion scalar is also imposed. Moreover, a kinetic term for the torsion is also included in the gravitational action. The field equations of the model are obtained from a Hilbert-Einstein type variational principle, and they lead to a complete description of the gravitational field in terms of two fields, the Weyl vector and the torsion, respectively, defined in a curved background. The cosmological applications of the model are investigated for a particular choice of the free parameters in which the torsion vector is proportional to the Weyl vector. Depending on the numerical values of the parameters of the cosmological model, a large variety of dynamic evolutions can be obtained, ranging from inflationary/accelerated expansions to non-inflationary behaviors. In particular we show that a de Sitter type late time evolution can be naturally obtained from the field equations of the model. Therefore the present model leads to the possibility of a purely geometrical description of the dark energy, in which the late time acceleration of the Universe is determined by the intrinsic geometry of the space-time.

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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