On the Rotation Curve of Disk Galaxies in General Relativity
Date: 21 FEBRUARY 2023 from 14:00 to 15:00
Event location: Room IR-1A
Recently, it has been suggested that the phenomenology of flat rotation curves of disk galaxies can be explained as a manifestation of general relativity (GR) instead of the effect of dark matter (DM) halos. By using the well-known gravitomagnetic formulation of GR, the expected rotation curves in GR are obtained for purely baryonic disk models with realistic density profiles and compared with the predictions of Newtonian gravity for the same disks in absence of DM. As expected, the resulting rotation curves are indistinguishable, with GR corrections at all radii of the order v 2/c 2 ≈ 10-6. Therefore, the observed phenomenology of galactic rotation curves at large radii requires DM in GR exactly as in Newtonian gravity, unless the weak-field approximation of GR cannot be applied to the study of rotating systems in the weak-field regime. A list of additional astrophysical problems/observations that should be convincingly addressed in the proposed GR scenario will be also presented and discussed.