  Establishing that Vera C. Rubin Observatory is a flagship dark matter
experiment is an essential pathway toward understanding the physical nature of
dark matter. In the past two decades, wide-field astronomical surveys and
terrestrial laboratories have jointly created a phase transition in the
ecosystem of dark matter models and probes. Going forward, any robust
understanding of dark matter requires astronomical observations, which still
provide the only empirical evidence for dark matter to date. We have a unique
opportunity right now to create a dark matter experiment with Rubin Observatory
Legacy Survey of Space and Time (LSST). This experiment will be a coordinated
effort to perform dark matter research, and provide a large collaborative team
of scientists with the necessary organizational and funding supports. This
approach leverages existing investments in Rubin. Studies of dark matter with
Rubin LSST will also guide the design of, and confirm the results from, other
dark matter experiments. Supporting a collaborative team to carry out a dark
matter experiment with Rubin LSST is the key to achieving the dark matter
science goals that have already been identified as high priority by the
high-energy physics and astronomy communities.
