论文标题
对通货膨胀替代方案的各向异性的观察限制
Observational constraints on anisotropies for bouncing alternatives to inflation
论文作者
论文摘要
我们计算背景时期的原始各向异性如何影响宇宙学扰动的演变，以弹跳通货膨胀的替代方案，例如ekpyrosis和物质反弹情景。我们发现，各向异性在宇宙的收缩阶段的领先顺序效应是在具有非常具体形式的宇宙微波背景中诱导各向异性：一种比例不变的四极角分布。亚领效应是角度分布中高阶矩的产生，以及标量和张量模式之间的互相关。我们还发现，四极力矩的宇宙微波背景的观察约束在允许各向异性方面具有强大的界限，用于弹跳通货膨胀的替代方案，这些替代方案比以前使用缩放参数基于猜测的Belinski-Khalatnikov-lifshitz稳定性相比，其限制性更大。
We calculate how primordial anisotropies in the background space-time affect the evolution of cosmological perturbations for bouncing alternatives to inflation, like ekpyrosis and the matter bounce scenario. We find that the leading order effect of anisotropies in the contracting phase of the universe is to induce anisotropies in the cosmic microwave background with a very concrete form: a scale-invariant quadrupolar angular distribution. Sub-leading effects are the generation of higher-order moments in the angular distribution, as well as cross-correlations between scalar and tensor modes. We also find that observational constraints from the cosmic microwave background on the quadrupole moment provide strong bounds on allowed anisotropies for bouncing alternatives to inflation that are significantly more constraining than the bounds previously obtained using scaling arguments based on the conjectured Belinski-Khalatnikov-Lifshitz instability.
