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

这个博士学位项目将通过将随机通货膨胀方法与完全非线性的一般相对论进化相结合，从而从通货膨胀模型中进行定量统计预测，从而促进了早期宇宙通货膨胀理论，该理论解释了宇宙中星系和大规模结构的起源。非高斯签名固有地存在于原始波动中，这是由于一般相对论所产生的非线性以及负责驱动通货膨胀的潜力可能正在相互作用的事实。该项目的目的是在分析和数字上对非线性通货膨胀动力学进行建模，以使Bipectrum（三点）和其他高阶相关器预测包括更广泛的通货膨胀场景（包括具有多个领域的那些）；这是竞争通货膨胀模型之间的重要歧视，可用于在观察上区分它们。这将通过利用新的Grchombo数值相对论来实现这一目标，以使用完整的3D一般相对论模拟来计算这些非线性效应，从而通过包含在通货膨胀期间放大的量子波动来增强它。后者将作为随机源术语实施，该术语将集成在Grchombo Evolution例程中，并且将通过有效的现场理论中的扰动分析计算确定。由博士主管Shellard领导的DAMTP宇宙学家能够通过使用创新的可分离技术（模态管道）从Planck Microwave（CMB）提取温度和极化双线（CMB）来限制广泛的通货膨胀情况；现在将其应用于CMB实验（Simons天文台）和Galaxy Surveys（SDSS，DES及以后）的新观测数据集。来自该博士学位项目的随机非线性GR模拟的最终的3D字段将直接通过这些技术进行分析，从而通过宇宙学数据推进了通货膨胀理论的详细对抗