Probing the Early Cosmological History with Dark Matter

University Of New Mexico, Albuquerque NM

Investigators

Abstract

This award funds the research activities of Professor Rouzbeh Allahverdi at the University of New Mexico. We know from observations that only 15% of the matter in the universe is described by the Standard Model of particle physics, while 85% is made of dark matter. However, the nature and origin of dark matter remains one of the most profound problems at the interface of particle physics and cosmology. A whole array of dark-matter detection experiments, combined with experiments at the Large Hadron Collider (LHC), will help us discover the dark matter and establish its particle-physics origin. The complementary information provided by these experiments will also play a crucial role in examining how the present-day energy density of the dark matter was determined. The research funded by this award will combine theoretical models and observational signatures of dark matter to probe the early cosmological history. Research in this area thus advances the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical law. The research funded by this award will also have significant broader impacts. Professor Allahverdi will involve graduate and undergraduate students in his research, and thereby provide critical training to junior physicists beginning research in this field. The PI will additionally bring his results to a broader audience through job shadowing and mentorship of high-school students, as well as by visiting schools and giving public lectures. More technically, the research supported by this award focuses on using dark matter to probe the thermal history of the universe when it was a tiny fraction of a second old. It includes investigations of dark-matter models and production mechanisms having a three-fold goal. First, the PI wishes to use particle physics experiments along with cosmological observations to reconstruct the thermal history of the early universe. Second, the PI wishes to constrain novel dark-matter production mechanisms by employing their distinct observable signatures. Third, the PI wishes to study particle-physics models that not only accommodate dark matter but also address the matter-antimatter asymmetry of the universe, and explore the novel testable predictions of such models. To achieve these objectives, Professor Allahverdi will build new particle-physics models of dark matter, study dark-matter production in alternative thermal histories before one second, and investigate the novel predictions of different production mechanisms that can be tested in various experiments. These investigations will help us determine the deeper theoretical origin of the DM and its embedding within a fundamental theory. They will also enable us to probe the thermal history of the universe that is out of the reach of our best observational probes --- namely the cosmic microwave background and Big Bang nucleosynthesis --- at the present time. 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.