Astronomy Lunch Series
Nicole Dracos
(UW)
Although the current cosmological model, ΛCDM, is largely successful in describing our universe, the nature and identity of dark matter and dark energy remain unclear, and ΛCDM may have problems describing structure on small scales. Additionally, there are mild tensions in cosmological parameters, possibly indicating a need for an extension to the current cosmological model. Dark matter halos provide a way to study some of these problems, as their properties reflect the formation history of the universe and can be used to understand the underlying cosmology. In this talk, I will present a simple, physically motivated model we developed to predict the evolution of tidally stripped halos, which has applications to predictions of dark matter annihilation and lensing signals. Secondly, I will present a large set of dark matter only simulations used to predict the evolution of halo structural properties including shape, concentration and density profiles in binary equal mass halo mergers. Finally, I will outline a potential independent cosmological test to constrain σ8. Overall, this talk will demonstrate some of the ways in which dark matter halo properties provide insight into the history of the universe.