The virial theorem in Eddington-Born-Infeld gravity
Abstract
We consider the possibility that the Eddington-Born-Infeld (EBI) modified gravity provides an alternative explanation for the mass discrepancy in clusters of galaxies. For this purpose we derive the modified Einstein field equations, finding an additional "geometrical mass" term which provides an effective contribution to the gravitational binding energy. Using some approximations and assumptions for weak gravitational fields, and taking into account the collisionless relativistic Boltzmann equation, we derive a generalized version of the virial theorem in the framework of EBI gravity. We show that the "geometrical mass" term may account for the well known virial mass discrepancy in clusters of galaxies. We also derive the velocity dispersion relation for galaxies in the clusters, which could provide an efficient method for testing EBI gravity from astrophysical observations.
Cite
@article{arxiv.1506.04569,
title = {The virial theorem in Eddington-Born-Infeld gravity},
author = {Noelia S. Santos and Janilo Santos},
journal= {arXiv preprint arXiv:1506.04569},
year = {2015}
}
Comments
15 pages; no figures. Improved version, some comments and References added. Submitted to publication. arXiv admin note: text overlap with arXiv:0710.0966, arXiv:1212.5817 by other authors