A spherical scalar-tensor galaxy model
Abstract
We build a spherical halo model for galaxies using a general scalar-tensor theory of gravity in its Newtonian limit. The scalar field is described by a time-independent Klein-Gordon equation with a source that is coupled to the standard Poisson equation of Newtonian gravity. Our model, by construction, fits both the observed rotation velocities of stars in spirals and a typical luminosity profile. As a result, the form of the new Newtonian potential, the scalar field, and dark matter distribution in a galaxy are determined. Taking into account the constraints for the fundamental parameters of the theory (lambda,alpha), we analyze the influence of the scalar field in the dark matter distribution, resulting in shallow density profiles in galactic centers.
Cite
@article{arxiv.0902.4865,
title = {A spherical scalar-tensor galaxy model},
author = {Jorge L. Cervantes-Cota and Mario A. Rodriguez-Meza and Dario Nunez},
journal= {arXiv preprint arXiv:0902.4865},
year = {2009}
}
Comments
14 pages, 16 plots set in 7 figures, typos and references added