Higher Derivative Gravity and Conformal Gravity from Bimetric and Partially Massless Bimetric Theory
Higher Derivative Gravity and Conformal Gravity from Bimetric and Partially Massless Bimetric Theory
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DOI：
10.3390/universe1020092
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发表时间：
2013-03
期刊：
影响因子：
2.9
通讯作者：
Sayed Fawad Hassan;A. Schmidt-May;M. Strauss
中科院分区：
文献类型：
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作者：
Sayed Fawad Hassan;A. Schmidt-May;M. Strauss
本文建立了无鬼对称理论与一类高导数引力作用的对应关系，包括保形引力和新型质量引力。我们还描述了各自的运动方程和经典解之间的关系。我们说明，在这个框架中，高导数重力在线性水平上的自旋-2幽灵是截断到四导数理论的人工产物。分析还给出了所提出的部分无质量（PM）对称理论与共形重力之间的关系，特别指出了它们的运动方程在四阶导数水平上的等价性。对于PM对称理论，这进一步证明了额外规范对称的存在以及远离德西特背景的传播模式的相关损失。新的对称是Weyl不变性的扩展，这可能表明候选的PM对称理论可能是保形引力的无鬼补全。
In this paper, we establish the correspondence between ghost-free bimetric theory and a class of higher derivative gravity actions, including conformal gravity and new massive gravity. We also characterize the relation between the respective equations of motion and classical solutions. We illustrate that, in this framework, the spin-2 ghost of higher derivative gravity at the linear level is an artifact of the truncation to a four-derivative theory. The analysis also gives a relation between the proposed partially massless (PM) bimetric theory and conformal gravity, showing, in particular, the equivalence of their equations of motion at the four-derivative level. For the PM bimetric theory, this provides further evidence for the existence of an extra gauge symmetry and the associated loss of a propagating mode away from de Sitter backgrounds. The new symmetry is an extension of Weyl invariance, which may suggest the candidate PM bimetric theory as a possible ghost-free completion of conformal gravity.