论文标题
非线性的无鬼较高曲率重力
Non-linearly ghost-free higher curvature gravity
论文作者
论文摘要
我们发现Vielbein形式主义中较高曲率重力的统一和局部理论，通过利用与无鬼魂的巨大巨大狂热的等效性，被称为庞加莱量规理论。我们特别关注三个和四个维度，但扩展到更高维度的时空非常简单。在三个维度中，二次重力$ \ MATHCAL {l} = r+t^2+r^2 $，其中$ r $是曲率，$ t $是省略指数的扭转，与Zwei-Dreibein Gravity相当，与完全非上线的幽灵释放。在特殊的限制中，回收了新的大型重力。当模型应用于AD/CFT对应关系时，批量理论和边界理论中的单位性都意味着扭转不得消失。另一方面，在四个维度上，在非线性订单上没有幽灵需要无限数量的较高的曲率项，并且这些术语可以通过示意图$ r（1+r/αm^2）^{ - 1} r $ $ $ M $的质量是$ $ $ $ $ $ $ $ $ n是$ $ $ n是$ a的范围。我们还提供了另一种四维无幽灵的高曲率理论，该理论包含巨大的Spin-0模式以及大量的Spin-2模式。
We find unitary and local theories of higher curvature gravity in the vielbein formalism, known as the Poincaré gauge theory by utilizing the equivalence to the ghost-free massive bigravity. We especially focus on three and four dimensions but extensions into a higher dimensional spacetime are straightforward. In three dimensions, a quadratic gravity $\mathcal{L}=R+T^2+R^2$, where $R$ is the curvature and $T$ is the torsion with indices omitted, is shown to be equivalent to zwei-dreibein gravity and free from the ghost at fully non-linear orders. In a special limit, new massive gravity is recovered. When the model is applied to the AdS/CFT correspondence, unitarity both in the bulk theory and in the boundary theory implies that the torsion must not vanish. On the other hand, in four dimensions, the absence of ghost at non-linear orders requires an infinite number of higher curvature terms, and these terms can be given by a schematic form $R(1+R/αm^2)^{-1}R$ where $m$ is the mass of the massive spin-2 mode originating from the higher curvature terms and $α$ is an additional parameter that determines the amplitude of the torsion. We also provide another four-dimensional ghost-free higher curvature theory that contains a massive spin-0 mode as well as the massive spin-2 mode.
