TY - JOUR
T1 - Towards a full general relativistic approach to galaxies
AU - Astesiano, Davide
AU - Cacciatori, Sergio L.
AU - Gorini, Vittorio
AU - Re, Federico
N1 - Funding Information: We thank Maria Teresa Crosta, Alexander Kamenshchik, Davi C. Rodrigues, Matteo Luca Ruggiero, Antonello Ortolan for useful discussions. We are particularly indebted to Elias Mégier for helping us in notably improving the exposition, and for useful discussions. Finally, we are very grateful to the Referee for having given us the opportunity to greatly improve the presentation of the paper. Publisher Copyright: © 2022, The Author(s).
PY - 2022/6
Y1 - 2022/6
N2 - We analyse the dynamics of a single disk galaxy from a general relativistic viewpoint. We investigate dark matter (DM) effects in terms of a known family of stationary axially-symmetric solutions of Einstein equations coupled to a rotating dust. These effects are generated by the non-Newtonian features of such solutions and are ascribed to the essential role of frame dragging. Indeed, in such models, the off-diagonal elements of the metric are, in general, of the same order of magnitude of the diagonal ones. We generalize the results of Balasin and Grumiller (BG) to the physical case of differentially rotating dust. In particular, we find that for differential rotation the amount of energy density required to account for the flat rotation curves of disk galaxies is reduced with respect to the BG rigid rotation case. This stresses the discrepancy between Newtonian gravity and general relativity (GR), even at low velocities and low energy densities.
AB - We analyse the dynamics of a single disk galaxy from a general relativistic viewpoint. We investigate dark matter (DM) effects in terms of a known family of stationary axially-symmetric solutions of Einstein equations coupled to a rotating dust. These effects are generated by the non-Newtonian features of such solutions and are ascribed to the essential role of frame dragging. Indeed, in such models, the off-diagonal elements of the metric are, in general, of the same order of magnitude of the diagonal ones. We generalize the results of Balasin and Grumiller (BG) to the physical case of differentially rotating dust. In particular, we find that for differential rotation the amount of energy density required to account for the flat rotation curves of disk galaxies is reduced with respect to the BG rigid rotation case. This stresses the discrepancy between Newtonian gravity and general relativity (GR), even at low velocities and low energy densities.
UR - https://www.scopus.com/pages/publications/85132944571
U2 - 10.1140/epjc/s10052-022-10506-7
DO - 10.1140/epjc/s10052-022-10506-7
M3 - Article
SN - 1434-6044
VL - 82
JO - European Physical Journal C
JF - European Physical Journal C
IS - 6
M1 - 554
ER -