Upper limit on the central density of dark matter in the Eddington-inspired Born-Infeld (EiBI) gravity

作者：Izmailov Ramil^*; Potapov Alexander A; Filippov Alexander I; Ghosh Mithun; Nandi Kamal K

来源：Modern Physics Letters A, 2015, 30(11): 1550056.

DOI：10.1142/S021773231550056X

• Dark matter
• central density
• upper limit

We investigate the stability of circular material orbits in the analytic galactic metric recently derived by Harko et al., Mod. Phys. Lett. A 29, 1450049 (2014). It turns out that stability depends more strongly on the dark matter central density rho(0) 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(upper)(0), such that stable circular orbits are possible only when the constraint rho(0) <= rho(upper)(0) 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-DM similar to 180 kpc and find that rho(upper)(0) similar to 2.37 x 10(11) M-circle dot 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 Eddington-inspired Born-Infeld (EiBI) solution could qualify as yet another viable alternative model for dark matter.

• 出版日期2015-4-10