Quantum Aspects of Matter Fields and Gravity

Louisiana State University, Baton Rouge LA

Investigators

Abstract

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.