Assessing dynamical friction issues under MOND via detailed self-consistent simulations

Develop and perform detailed self-consistent simulations in Modified Newtonian Dynamics (MOND) to ascertain whether the dynamical-friction-related inconsistencies identified for systems such as ultra-faint dwarfs, wide binaries in dwarfs, globular clusters in dwarfs, galactic bars, Milky Way satellites, the Large and Small Magellanic Clouds, and the M81 group are alleviated or persist under MOND.

Background

While the paper argues that Chandrasekhar dynamical friction yields contradictions for a wide range of systems if galaxies host particle dark matter halos, it notes that in MOND the situation could differ because no dark matter particle backgrounds exist to absorb angular momentum and energy. Analytical and simulation work to date has primarily addressed specific cases like globular clusters in dwarf galaxies, where MOND may mitigate friction issues relative to Newtonian gravity with dark matter.

The authors explicitly state that settling whether the other dynamical-friction problems discussed (e.g., for bars, satellite infall, the LMC–SMC system, and compact groups) persist or are alleviated in MOND requires detailed self-consistent simulations, which they indicate have not yet been carried out.