On the rotation curve of disk galaxies in General Relativity
Luca Ciotti (Unibo)
Tuesday 18/10/2022 @ 14:00, Sala IV piano Battiferro - Presenza + remoto
Recently, it has been suggested that flat rotation curves observed at large radii in disk galaxies are a manifestation of general relativity (GR), and not the effect of dark matter (DM) halos in newtonian gravity. In this talk I will briefly review the problem and discuss the most serious misunderstandings/misconceptions affecting oversimplified expositions of the problem. In the second part I will present the results I obtained by using the weak-field, low-velocity gravitomagnetic formulation of GR, applied to the case of purely baryonic disk models with realistic density profiles. It is found (as expected) that the GR corrections at all radii are 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.