Speaker
Description
Speaker: Sukanya Chakrabarti
Abstract: For over a century, our understanding of dark matter has hinged on kinematic estimates derived from static snapshots of stellar positions and velocities. However, these methods are inaccurate for a time-dependent potential, and there are now many lines of observational evidence that show that our Galaxy has had a highly dynamic history. Recent technological advancements now empower us to carry out precision time-series measurements of the acceleration of stars that live within the gravitational potential of our Galaxy. This presentation outlines our comprehensive observational strategy to directly measure Galactic accelerations. Central to this discussion is our recent analysis of compiled pulsar timing data from which we were able to measure the Galactic acceleration for the first time, and derive fundamental Galactic parameters, including the local dark matter density. Discernible differences in sub-structure exist among popular dark matter models on small scales, presenting testable nuances. I will discuss our recent constraints on a dark matter sub-halo near the Sun, and the potential for measuring dark matter sub-structure in the Milky Way by leveraging the diverse set of techniques we have developed, including pulsar timing, eclipse timing, and extreme-precision radial velocity observations. I will end by discussing synergies between Galactic dark matter constraints and constraints on theories of gravity.