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arXiv 1406.0822gr-qchep-th
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标量-张量引力理论的统一框架

Unifying framework for scalar-tensor theories of gravity

Xian Gao

摘要:

研究了传播两个张量和一个标量自由度的有效理论的一般框架。几何上,它描述了耦合到一般背景的类空超曲面的动力学叶理,其中标量模式编码超曲面的波动。在这个框架内,文献中的各种模型--包括$k$ -本质、Horndeski理论、暴胀的有效场论、鬼凝聚以及Hoenavava引力--得到了统一。我们的框架概括了Horndeski理论的意义,它传播的自由度的正确数量,虽然运动方程一般是高阶的。我们还确定了新的运营商超越Horndeski理论,产生二阶运动方程的线性扰动周围的弗里德曼-罗伯逊-沃克背景。

英文摘要:

A general framework for effective theories propagating two tensor and one scalar degrees of freedom is investigated. Geometrically, it describes dynamical foliation of spacelike hypersurfaces coupled to a general background, in which the scalar mode encodes the fluctuation of the hypersurfaces. Within this framework, various models in the literature---including $k$-essence, Horndeski theory, the effective field theory of inflation, ghost condensate as well as the Hořava gravity---get unified. Our framework generalizes the Horndeski theory in the sense that, it propagates the correct number of degrees of freedom, although the equations of motion are generally higher order. We also identify new operators beyond the Horndeski theory, which yield second order equations of motion for linear perturbations around an a Friedmann-Robertson-Walker background.

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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