标题： 宇宙学中的非最小导数耦合引力 显示英文标题

标题： Non-minimal derivative coupling gravity in cosmology

摘要： 我们简要回顾了非最小导数耦合（NMDC）标量场理论，在该理论中，标量场导数项与爱因斯坦张量之间存在非最小耦合。 我们假设对于小红移，膨胀是幂律型或超加速型。 拉格朗日量包括NMDC项、自由动能项、宇宙常数项和一个绝热物质项。 对于与膨胀相容的耦合常数值，我们使用组合的WMAP9 (WMAP9+eCMB+BAO+ $H_0$) 数据集、PLANCK+WP数据集以及PLANCK $TT,TE,EE$+lowP+Lensing+ext数据集来确定模型中的宇宙常数值。 用幂律模型描述膨胀得到负的宇宙常数，而幻影幂律（超加速）膨胀则给出正的宇宙常数且误差较大。 所得到的值与 $\Lambda$CDM模型中的值同阶，因为在晚期由于曲率较小，NMDC效应很小。 显示英文摘要

摘要： We give a brief review of the non-minimal derivative coupling (NMDC) scalar field theory in which there is non-minimal coupling between the scalar field derivative term and the Einstein tensor. We assume that the expansion is of power-law type or super-acceleration type for small redshift. The Lagrangian includes the NMDC term, a free kinetic term, a cosmological constant term and a barotropic matter term. For a value of the coupling constant that is compatible with inflation, we use the combined WMAP9 (WMAP9+eCMB+BAO+ $H_0$) dataset, the PLANCK+WP dataset, and the PLANCK $TT,TE,EE$+lowP+Lensing+ext datasets to find the value of the cosmological constant in the model. Modeling the expansion with power-law gives a negative cosmological constants while the phantom power-law (super-acceleration) expansion gives positive cosmological constant with large error bar. The value obtained is of the same order as in the $\Lambda$CDM model, since at late times the NMDC effect is tiny due to small curvature.