Quantum Aspects of Matter Fields and Gravity

科学中最重要的悬而未决的问题之一是引力与量子系统相互作用的方式。这是一个重要的问题，不仅在概念/基本层面上，而且作为一个实际问题。量子技术即将占据主导地位，准确了解它们在引力场存在时的行为方式，对于最大限度地利用它们在从通信到国防的各种应用中将是至关重要的。这项研究项目旨在调查不同的问题，在这些问题中，光的量子方面和其他物质场以及引力都发挥着重要作用。这项拟议的研究包括三个主题，旨在探索量子场论和引力之间关系的互补方面。其中两个与光在强引力场中的传播有关，有助于我们理解这种相互作用产生的微妙效应，如光的偏振反常行为，或引力诱导的量子纠缠现象。第三个主题涉及量子场在早期宇宙中的传播方式，目标是调查我们在宇宙微波背景中观察到的某些信号是否是早期宇宙中量子场和引力相互作用的结果，这些信号仍然无法解释。这些研究还将阐明引力在量子水平上的工作方式。这些项目包括：(I)调查早期宇宙的物理学及其观测结果。这是提案的主要部分。中心议题是继续由PI正在进行的努力，以评估反弹宇宙来描述早期宇宙的可信程度。更具体的是：在宇宙微波背景(CMB)中观察到的仍未解释的一系列特征，即CMB异常，是否可能是宇宙反弹的痕迹；各向异性下反弹宇宙的稳定性；以及对环状量子宇宙学等一些具体量子宇宙学理论预测的研究。(Ii)在弯曲时空的电动力学背景下，探索PI及其合作者最近引入的量子反常的物理后果，特别注意它与红外线电荷和记忆效应的关系。(Iii)研究黑洞和霍金辐射的光学类比，目的是描述霍金过程在这些系统中产生的纠缠结构，以及如何利用这种结构来增强我们观察这一过程的各个方面的能力。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Among the most important open questions in science is the way the force of gravity interacts with quantum systems. This is an important question, not only at a conceptual/fundamental level, but as a practical matter as well. Quantum technologies are about to take over, and a precise understanding of the way they behave in the presence of gravitational fields will be essential to make the most of them in applications which range from communications to defense. This research project aims to investigate different problems where quantum aspects of light and other matter fields and gravitation both play an important role. The proposed research includes three topics, aimed to explore complementary aspects of the relation between quantum field theory and gravitation. Two of them are related to the propagation of light in presence of strong gravitational fields, and will help us to understand subtle effects which arise from this interaction, such as the anomalous behavior of the polarization of light, or the phenomenon of gravitational-induced quantum entanglement. A third topic has to do with the way quantum fields propagated in the early universe, and the goal is to investigate whether certain signals we have observed in the cosmic microwave background, and which remain unexplained, are the results of the interaction between quantum fields and gravity in the early universe. These investigations will also shed light on the way gravitation works at the quantum level. The projects includes: (i) Investigations of the physics of the early universe and their observational consequences. This is the main part of the proposal. The central topic is to continue ongoing efforts by the PI to evaluate the plausibility of bouncing cosmologies to describe the early universe. More concretely: whether the family of features that have been observed in the cosmic microwave background (CMB) and remain unexplained, known as CMB anomalies, could be traces of a cosmic bounce; the stability of bouncing cosmologies under anisotropies; and the investigation of the predictions of some concrete theories of quantum cosmology, like loop quantum cosmology. (ii) The exploration of the physical consequences of a quantum anomaly recently introduced by the PI and his collaborators in the context of electrodynamics in curved spacetimes, with special attention to its relation with infra-red charges and the memory effect. (iii) The study of optical analogs of black holes and Hawking radiation, with the goal of characterizing the entanglement structure that the Hawking process produces in these systems, and the way this structure can be used to enhance our ability to observe aspects of this process.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.