标题： 从破损微分同胚中获得的$Λ$CDM 显示英文标题

标题： $Λ$CDM from broken diffeomorphisms

摘要： 我们提出一个在微分同胚下具有约化不变性的简单场论模型，其能量-动量张量与无压无旋物质和宇宙学常数的和相同。 该模型的作用量由一个具有规范动能项的标量场构成，没有任何势能或拉格朗日乘子项。 与引力的耦合是通过一个特定的横向微分同胚不变体积元素实现的。 相应的声速在任何背景几何中都精确为零，该模型在动力学上等价于$\Lambda$CDM。 通过引入类似史蒂克尔伯格的场来恢复完整的微分同胚不变性，我们得到一个等效的局部标量-矢量理论。 显示英文摘要

摘要： We present a simple field theory model with reduced invariance under diffeomorphisms whose energy-momentum tensor is identical to the sum of pressureless irrotational matter and a cosmological constant. The model action is built from a single scalar field with a canonical kinetic term without any potential or Lagrange multiplier terms. The coupling to gravity is realized through a particular transverse diffeomorphism invariant volume element. The corresponding sound speed is exactly zero in any background geometry and the model is dynamically identical to $\Lambda$CDM. By restoring the full diffeomorphism invariance through the introduction of Stueckelberg-like fields, we obtain an equivalent local scalar-vector theory.