New Physics Signatures in Cosmological Observations

Brown University, Providence RI

Investigators

Abstract

This award funds the research activities of Professor Savvas M. Koushiappas at Brown University. Despite exciting experimental progress over the last two decades, several problems remain and new ones have appeared with the increased precision of cosmological experiments. The nature of dark matter and dark energy remain elusive, the distribution of dark matter in halos may hint to physics beyond the Standard Model of particle physics, and the search for quantum gravity remains an open question. New physics is necessitated to address these questions. The award bridges the gap between cosmology, particle physics, and astrophysics, and is in line with the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical laws. The projects in this award have also significant broader impacts. Professor Koushiappas will involve graduate students in his research and provide critical training for junior scientists in a STEM field. In addition, he will present public lectures on contemporary topics in cosmology as well as develop new courses that stem from the results of this research. Under this award, Professor Koushiappas will explore the effects of ultra-light dark matter in the accumulation of angular momentum in galactic systems. Angular momentum in dark matter halos is built-up in the linear and quasi-linear regime from the coupling between the mass distribution of the dark matter halo and the mass distribution of the neighboring density fluctuation field. Ultra-light dark matter has a different mass distribution compared to cold dark matter. This award will explore the effects of ultra-light dark matter in the angular momentum content of dark matter halos, with the goal of using current and future observables as constraints on the nature of dark matter. In addition, this award will investigate new possible interactions between dark matter and collision-less particles (stars and black holes) in dark matter dominated systems. Furthermore, work under this award will search for imprints quantum and/or modified gravity on cosmological observations through the growth of structure. 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.