CAREER: The Early Universe as a Window to Quantum Gravity

最近的观测发现了宇宙起源后瞬间发生的物理过程的残余。然而，我们目前用来解释这些数据的理论工具还远远不够完善。一个关键的困难是如何使爱因斯坦的引力理论与量子力学相一致。目前的项目试图通过将量子引力的新思想纳入宇宙学来填补这一空白。这个项目的目标是双重的：扩展我们对宇宙起源和命运的理解，并利用最后一代宇宙学观测来测试量子引力的最新发展。此外，该奖项还支持一些教育计划，通过创建新课程以及与LIGO科学教育中心协调的外展项目，加强研究生和本科生的宇宙学教学。该奖项支持旨在发展将量子引力物理纳入早期宇宙模型的理论方法的研究。研究将集中在量子宇宙学的理论和现象学方面，特别强调来自环量子引力的技术。从理论的角度来看，它将探索物质场如何在引力量子方面很重要的情况下传播，以及弯曲时空中熟悉的量子场论如何从更基本的理论中出现。从现象学的观点来看，由此产生的理论框架将被应用于扩展宇宙学模型，以包括普朗克尺度物理。研究将涵盖导致宇宙微波背景和星系分布中的温度各向异性的标量扰动、非高斯性、原始磁场和早期宇宙产生的引力波。还将注意寻找解释最近在宇宙微波背景中观察到的一些异常的机制。这个项目的结果有望加强量子引力和宇宙学之间的桥梁，为两个领域带来好处。

Recent observations have detected remnants of physical processes that occurred a tiny fraction of second after the origin of the universe. However, the theoretical tools we have at present to interpret these data are far from complete. A key difficulty is how to make Einstein's theory of gravity consistent with quantum mechanics. The present project seeks to contribute to filling this gap by incorporating new ideas in quantum gravity to cosmology. The goal of this project is twofold: to extend our understanding of the origin and fate of the universe, and to use the last generation of cosmological observations to test recent developments in quantum-gravity. Additionally, this award supports several educational initiatives that enhance the teaching of cosmology at graduate and undergraduate levels through the creation of new courses as well as outreach projects in coordination with the LIGO Science Education Center.This award supports research aimed at developing theoretical methods to incorporate quantum gravity physics in models of the early universe. Investigations will focus on theoretical as well as phenomenological aspects of quantum cosmology, with special emphasis on techniques coming from loop quantum gravity. From the theoretical point of view, it will be explored how matter fields propagate on regimes where quantum aspects of gravity are important, and the way in which the familiar quantum field theory in curved space-times emerges from the more fundamental theory. From the phenomenological viewpoint, the resulting theoretical framework will be applied to extend cosmological models to include Planck scale physics. Investigations will cover scalar perturbations that are responsible for the temperature anisotropies in the cosmic microwave background and galaxy distribution, non-Gaussianity, primordial magnetic fields, and gravitational waves generated in the early universe. Attention will also be paid to find mechanisms to account for some anomalies recently observed in cosmic microwave background. The results of this project are expected to reinforce the bridge between quantum gravity and cosmology, producing benefits for both fields.