GR Dynamics of Stochastic Inflation

随机通货膨胀的 GR 动力学

• 批准号: 2758438
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2758438
• 关键词: GR; Dynamics; Stochastic; Inflation

This PhD project will advance the early universe theory of inflation, which explains the origin of galaxies and large-scale structure in the Universe, by merging stochastic inflation methods with fully nonlinear General relativistic evolution to make quantitative statistical predictions from inflationary models. Non-Gaussian signatures are inherently present in primordial fluctuations due to the nonlinearities produced by both general relativity and the fact that the potential responsible for driving inflation may be interacting. The goal of this project is to analytically and numerically model nonlinear inflationary dynamics in order to make bispectrum (three-point) and other higher-order correlator predictions which encompass a much broader range of inflationary scenarios (including those with multiple fields); this is an important discriminant between competing inflation models that can be used to distinguish them observationally. This will be achieved by exploiting the new GRChombo numerical relativity pipeline to compute these nonlinear effects using full 3D general relativistic simulations, augmenting it by the inclusion of quantum fluctuations that get amplified during Inflation. The latter will be implemented as stochastic source terms to be integrated within the GRChombo evolution routines and which, in turn, will be determined via perturbative analytic computations from effective field theory. DAMTP cosmologists, led by the PhD supervisor Shellard, have been able to constrain a wide range of inflationary scenarios by using innovative separable techniques (the MODAL pipeline) to extract and reconstruct the temperature and polarization bispectra from Planck satellite maps of the cosmic microwave background (CMB); this is now being applied to new observational data sets from both CMB experiments (Simons Observatory) and galaxy surveys (SDSS, DES and beyond). The resulting 3D fields of the stochastic nonlinear GR simulations from this PhD project will be directly amenable to analysis by these techniques, advancing the detailed confrontation of inflationary theory with cosmological data

这个博士项目将推进早期宇宙膨胀理论，解释宇宙中星系和大尺度结构的起源，通过将随机膨胀方法与完全非线性广义相对论演化相结合，从膨胀模型中进行定量统计预测。由于广义相对论产生的非线性和导致暴胀的势可能相互作用的事实，非高斯特征固有地存在于原始波动中。该项目的目标是分析和数值模拟非线性暴胀动力学，以使双谱（三点）和其他高阶相关预测，其中包括更广泛的暴胀情景（包括那些与多个领域）;这是一个重要的判别竞争的通货膨胀模型，可以用来区分它们的观测。这将通过利用新的GRChombo数值相对论管道来实现，使用完整的3D广义相对论模拟来计算这些非线性效应，并通过包含在暴胀期间放大的量子涨落来增强它。后者将被实施为随机源项内的GRChombo进化例程，这反过来，将通过有效场理论的微扰分析计算来确定集成。由博士生导师Shellard领导的DAMTP宇宙学家已经能够通过使用创新的可分离技术来限制大范围的暴胀场景（MODAL管道），从宇宙微波背景（CMB）的普朗克卫星图中提取和重建温度和偏振双谱;这一方法现在正被应用于CMB实验（西蒙斯天文台）和星系巡天（SDSS、DES及更远）的新观测数据集。这个博士项目的随机非线性GR模拟产生的3D场将直接适用于这些技术的分析，推进了暴胀理论与宇宙学数据的详细对抗