论文标题
僵硬曲率扰动的遗物引力
Relic gravitons from stiff curvature perturbations
论文作者
论文摘要
当等离子体由刚性流体导致光谱能量密度支配时，张量模式重新进入哈勃半径，其蓝色斜率取决于总的通货膨胀后声速。然而，该结果通过来自曲率不均匀性的二次（依赖依赖性）项来纠正，这些项沿着相同的膨胀阶段重新进入。与一阶结果相比，次级贡献被证明在声音范围内始终被抑制，因此，对于所有现象学目的而言，它对遗物重力的总光谱能量密度的影响都可以忽略不计。还提出，曲率不均匀性的有效各向异性应力可以从相对于背景度量的曲率不均匀性的二阶作用的功能导数获得。
The tensor modes reentering the Hubble radius when the plasma is dominated by a stiff fluid lead to a spectral energy density whose blue slope depends on the total post-inflationary sound speed. This result gets however corrected by a secondary (gauge-dependent) term coming from the curvature inhomogeneities that reenter all along the same stage of expansion. In comparison with the first-order result, the secondary contribution is shown to be always suppressed inside the sound horizon and its effect on the total spectral energy density of the relic gravitons is therefore negligible for all phenomenological purposes. It is also suggested that the effective anisotropic stress of the curvature inhomogeneities can be obtained from the functional derivative of the second-order action of curvature inhomogeneities with respect to the background metric.
