Investigating Fundamental Physics with Cosmological Probes

Tufts University, Medford MA

Investigators

Abstract

This award funds the research activities of Professor Mark Hertzberg at Tufts University. Many branches of modern physics are built upon the Standard Model of particle physics and cosmology. Future developments in fundamental physics will arise from addressing several unexplained features of our universe. Some of the most pressing questions arise in cosmology: What physics lies beyond the Standard Model that might be relevant to the early universe? What is the nature of dark matter? What is the underlying structure of gravitation? As part of his research, Professor Hertzberg will investigate specific aspects of these important questions by building theoretical models and comparing to cosmological data. This research therefore advances the national interest by pursuing basic scientific questions of high significance. This project will also have broader impacts. It will involve mentees, who will play an important role in developing models and in computational work, and help them develop essential research skills. More technically, this project will explore new physics required for consistent dynamics of the Standard Model after inflation, explore novel probes of light axion dark matter and new dark-matter models, and investigate the origin of Poincare symmetry from consistency of the gravitational sector. This work involves forming theoretical models, requiring both internal consistency and agreement with observations, all studied rigorously using the guiding principles of effective field theory. On the front concerning physics beyond the Standard Model, the primary objectives are to constrain features of the Standard Model, including the Higgs boson and models of inflation, from consistency with early-universe dynamics. On the dark-matter front, the primary objectives are to investigate astrophysical consequences from dark-matter candidates, such as novel properties of axions, and to explore natural models of dark matter. On the gravitational front, the primary objectives are to determine the necessary and sufficient conditions to build a local theory of gravitons. 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.