Upper Limit on the Central Density of Dark Matter in the Eddington inspired Born-Infield (EiBI) Gravity

Abstract

We investigate the stability of circular material orbits in the analytic galactic metric recently derived by Harko \textit{et al.} (2014). It turnsout that stability depends more strongly on the dark matter central density than on other parameters of the solution. This property then yields an upper limit on ${\rho }_0$ for each individual galaxy, which we call here ${\rho }_0^{\text{upper}}$, such that stable circular orbits are possible \textit{only} when the constraint ${\rho }_0\le {\rho }_0^{\text{upper}}$ is satisfied. This is our new result. To approximately quantify the upper limit, we consider as a familiar example our Milky Way galaxy that has a projected dark matter radius $R_{\text{DM}}\sim 180$ kpc and find that ${\rho }_0^{\text{upper}}\sim 2.37\times 10^{11}$ $M_{\odot }$kpc${}^{-3}$. This limit turns out to be about four orders of magnitude larger than the latest data on central density ${\rho }_0$ arising from the fit to the Navarro-Frenk-White (NFW) and Burkert density profiles. Such consistency indicates that the EiBI solution could qualify as yet another viable alternative model for dark matter.

12 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1412.7897

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Cited by in corpus (3)

• Towards the Quantization of Eddington-inspired-Born-Infeld Theory
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• Mass decomposition of SLACS lens galaxies in Weyl conformal gravity