Research on the evolution of the Universe based on high precision data

这一研究计划的初衷是建立一个一致的早期宇宙演化史，它可以解释第一年WMAP结果的两个新特征，即曲率扰动的光谱指数运行和基于首席研究员和合作者提出的暴涨模型实现早期再电离的早期恒星形成。该项目的另一个目的是探索重模量场和引力对暗物质形成和热历史的宇宙学后果。虽然项目本身按照我们最初的设计进行了实践，但在项目研究期间披露的三年WMAP数据撤回了他们之前关于早期再电离的说法，因此我们对项目进行了相应的重组。主要研究成果如下：1.在我们的膨胀模型中，我们发现密度扰动的参数放大可以导致中等质量原始黑洞的形成.2.在多个标量场的运动决定暴胀轨迹的情况下，我们建立了适当的曲率扰动公式.3.我们计算了在运行谱指数存在的情况下对中微子质量的约束，得到了一个比以前更严格的界限.4.分析了中微子对引力子的模衰变和随后对中微子暗物质的衰变，表明存在一个实现适当暗物质丰度的参数区域.5.我们给出了振荡的命运6我们提出了一种从宇宙微波背景辐射的偏振数据中重建起伏原始功率谱的方法。7我们同时使用宇宙反演和最大似然矩阵方法重建原始功率谱。

This research project was originally planned to make a consistent evolution history of the early Universe which can account for the two new features of the first-year WMAP results, namely, running of spectral index of the curvature perturbations and early star formation which realizes early reionization based on the model of inflation proposed by the head investigator and collaborators. The other purpose of the project was to pursue the cosmological consequences of heavy moduli fields and gravitinos on dark matter formation and the thermal history. While the project itself was put into practice as we originally designed, the three-year WMAP data, which was disclosed during the research period of this project, withdrew their previous claim of early reionization, so that we reorganized the project accordingly. The main research outcomes are listed as follows.1 We discovered parametric amplification of density perturbations in our model of inflation which can result in intermediate mass primordial black hole formation.2 We established a proper formulation of curvature perturbation in the situation where motion of multiple scalar fields determines the trajectory of the inflaton.3 We calculated the constraint on the neutrino mass in the presence of running spectral index and obtained a more stringent bound than before.4 We analyzed modulus decay to gravitinos and their subsequent decay to neutralino dark matter and showed there was a parameter region that realizes the proper dark matter abundance.5 We formulated fate of the oscillating scalar fields using nonequilibrium quantum field theory.6 We proposed a method to reconstruct primordial power spectrum of fluctuations out of the polarization data of the cosmic microwave background radiation.7 We reconstructed primordial power spectrum using both cosmic inversion and maximum-likelihood matrix method.