2019/03/24 by Vincent Deledicque, Deledicque, Vincent
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Gravitation Theories #Experimental and Theoretical Physics Studies #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #General Relativity and Quantum Cosmology (gr-qc) #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.1903.10061
openalex publication_date 2019/03/24 · openalex created_date 2022/07/29 · openalex updated_date 2026/07/28
The dark matter hypothesis, which is not called into question here, explains\nwhy typical rotation curves of spiral galaxies do not follow a Keplerian\nprofile. It is however not sufficient in itself to explain why the whole matter\ndistribution in spiral galaxies is such that the rotation curve generally\npresents a flat profile in the disk region.\n To understand this property, a model considering general relativistic effects\nis developed. It is stressed that the aim is not to explain the flat rotation\ncurve of spiral galaxies without dark matter. More specifically, the analytical\nstationary solution of an axisymmetric rotating pressureless fluid for the\nlinearized equations of the theory of general relativity is determined. It is\ndemonstrated that this solution leads to some constraints on the rotation\ncurve, by looking to its limit behavior when neglecting general relativistic\neffects. In particular, the positiveness of the density imposes the rotation\ncurve to be flat in the regions where the density and general relativistic\neffects are small, such as in the disk region. General relativistic effects\nhence remain negligible in the disk region, but their consideration proved to\nbe necessary to establish the aforementioned constraint. Such constraint cannot\nbe derived from a Newtonian approach.\n The model is finally applied on two specific cases to demonstrate its ability\nto predict the rotation curve from a typical density profile along the galactic\nplane. These examples suggest that for some galaxies, general relativistic\neffects can be significant close to the bulge region and should be taken into\naccount to have a proper understanding of their rotation curve.\n