How do scientists utilize rogue stars to map the distribution of dark matter?

By observing how the star's trajectory is influenced by gravitational halos

The path taken by an ejected star is dictated by the gravitational environment it travels through, particularly the dark matter halo surrounding its parent galaxy. By carefully observing the speed and trajectory of these rogues, scientists can test current models of mass distribution. If a star's path deviates from predicted trajectories, it provides evidence regarding the presence and density of dark matter. Essentially, these stars act as gravitational probes, allowing researchers to 'weigh' a galaxy and understand the invisible scaffolding that holds it together.