CAREER: The Early Universe as a Window to Quantum Gravity

Louisiana State University, Baton Rouge LA

Investigators

Abstract

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.