论文标题
对遗物重力的频谱能量密度的高阶贡献的伪规行变量
Spurious gauge-invariance of higher-order contributions to the spectral energy density of the relic gravitons
论文作者
论文摘要
与几何形状的张量模式相关的能量密度相同，可以改变曲率扰动的演变，标量模式也可能通过诱导只有实质性计算机的高阶校正来诱导遗物重力的宇宙背景而间接地影响遗物重力的宇宙背景。当在不同坐标系统中计算的有效各向异性应力以一种仅取决于曲率不均匀性定义在正交性高度外表面和相应的时间导数中定义的曲率不均匀性时，这种虚假的量规不变性就会显现出现。使用此观察结果，我们以一般的术语证明，当波长小于声音范围时，在不同的坐标系统中得出的高阶贡献会重合定义曲率不均匀性的演变，但它们导致相反极限的急剧不同。当遗物重力的能量密度源自竞争的能量伪造量时，就会出现类似的缺点，并且在相关的现象学讨论中应始终如一地考虑到。
In the same way as the energy density associated with the tensor modes of the geometry modifies the evolution of the curvature perturbations, the scalar modes may also indirectly affect the cosmic backgrounds of relic gravitons by inducing higher-order corrections that are only superficially gauge-invariant. This spurious gauge-invariance gets manifest when the effective anisotropic stresses, computed in different coordinate systems, are preliminarily expressed in a form that only depends on the curvature inhomogeneities defined on comoving orthogonal hypersurfaces and on their corresponding time derivatives. Using this observation we demonstrate in general terms that the higher-order contributions derived in diverse coordinate systems coincide when the wavelengths are smaller than the sound horizon defining the evolution of the curvature inhomogeneities but they lead to sharply different results in the opposite limit. A similar drawback arises when the energy density of the relic gravitons is derived from competing energy-momentum pseudo-tensors and should be consistently taken into account in the related phenomenological discussions.
