标题： 原初非高斯性中的空间曲率遗迹 显示英文标题

标题： Relics of spatial curvature in the primordial non-gaussianity

摘要： 我们研究在暴胀时期之前存在强空间曲率时，对当前宇宙产生的宇宙微波背景（CMB）中的信号。 如果暴胀持续时间不足以将大尺度空间曲率驱动至零，那么目前可观测的尺度可能在空间切片无法近似为平坦的欧几里得几何时就已经离开了视界。 我们在这种情况下计算了CMB温度各向异性功率谱和非高斯性的修正。 功率谱不会受到显著修正，并且在初始条件中存在曲率的情况下是一个弱诊断工具，除非可以以高精度确定其运行。 然而，bispectral非高斯性参数f_NL在最大的可观测尺度上会有所改变。 我们估计最大信号对应的f_NL约为0.3，这超出了当前微波背景实验的探测能力。 显示英文摘要

摘要： We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the large-scale spatial curvature to zero, then presently observable scales may have left the horizon while spatial slices could not be approximated by a flat, Euclidean geometry. We compute corrections to the power spectrum and non-gaussianity of the CMB temperature anisotropy in this scenario. The power spectrum does not receive significant corrections and is a weak diagnostic of the presence of curvature in the initial conditions, unless its running can be determined with high accuracy. However, the bispectral non-gaussianity parameter f_NL receives modifications on the largest observable scales. We estimate that the maximum signal would correspond to f_NL ~ 0.3, which is out of reach for present-day microwave background experiments.