We construct a general effective dynamics for diffeomorphisms of spacetime, in a fixed external metric. Though related to familiar models of scalar fields as coordinates, our models have subtly different properties, both at kinematical and dynamical level. The energy–momentum (EM) tensor consists of two independently conserved parts. The background solution is the identity diffeomorphism and the EM tensor of this solution gives rise to an effective cosmological constant.

中文翻译：

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动力学微分同胚

我们以固定的外部度量为时空的微分同胚构建了一个通用的有效动力学。虽然与作为坐标的标量场模型相关，但我们的模型在运动学和动力学层面具有微妙的不同属性。能量-动量 (EM) 张量由两个独立守恒的部分组成。背景解是恒等微分同胚，这个解的 EM 张量产生了一个有效的宇宙学常数。