论文标题
拓扑引力作为我们宇宙的早期阶段
Topological Gravity as the Early Phase of Our Universe
论文作者
论文摘要
由弦二元性激励，我们将拓扑引力作为宇宙的早期阶段。该阶段的拓扑性质自然导致解释了早期宇宙宇宙学的许多难题。考虑了使用Witten的四维拓扑引力来实现这种情况的具体实现。该模型导致CMB波动的功率谱，该电源由共形异常系数$ a，c $控制。特别是，波动的强度由$ 1/a $控制，其倾斜度为$ c g^2 $，其中$ g $是拓扑重力的耦合常数。 $ c $的积极性是单位性的结果，它会自动导致功率谱的红外线倾斜。与标准通货膨胀模型相反，此情况预测$ \ Mathcal {o}（1）$非高西度为四点和更高点相关器，并且CMB波动中没有张量模式。
Motivated by string dualities we propose topological gravity as the early phase of our universe. The topological nature of this phase naturally leads to the explanation of many of the puzzles of early universe cosmology. A concrete realization of this scenario using Witten's four dimensional topological gravity is considered. This model leads to the power spectrum of CMB fluctuations which is controlled by the conformal anomaly coefficients $a,c$. In particular the strength of the fluctuation is controlled by $1/a$ and its tilt by $c g^2$ where $g$ is the coupling constant of topological gravity. The positivity of $c$, a consequence of unitarity, leads automatically to an IR tilt for the power spectrum. In contrast with standard inflationary models, this scenario predicts $\mathcal{O}(1)$ non-Gaussianities for four- and higher-point correlators and the absence of tensor modes in the CMB fluctuations.
