The Milky Way rotation curve in Horava - Lifshitz theory

Abstract

The Horava - Lifshitz (HL) theory has recently attracted a lot of interest as a viable solution to some quantum gravity related problems and the presence of an effective cosmological constant able to drive the cosmic speed up. We show here that, in the weak field limit, the HL proposal leads to a modification of the gravitational potential because of two additive terms (scaling respectively as $r^2$ and $r^{-4}$) to the Newtonian $1/r$ potential. We then derive a general expression to compute the rotation curve of an extended system under the assumption that the mass density only depends on the cylindrical coordinates $(R,z)$ showing that the HL modification induces a dependence of the circular velocity on the mass function which is a new feature of the theory. As a first exploratory analysis, we then try fitting the Milky Way rotation curve using its visible components only in order to see whether the HL modified potential can be an alternative to the dark matter framework. This turns out not to be the case so that we argue that dark matter is still needed, but the amount of dark matter and the dark halo density profile have to be revised according to the new HL potential.

10 pages, 1 figure, accepted for publication on MNRAS

References in corpus (9)

• Quantum Gravity at a Lifshitz Point
• Spectral Dimension of the Universe in Quantum Gravity at a Lifshitz Point
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• Low surface brightness galaxies rotation curves in the low energy limit of $R^n$ gravity : no need for dark matter?
• Horava-Lifshitz Cosmology
• Solutions to Horava Gravity
• Phenomenologically viable Lorentz-violating quantum gravity
• General static spherically symmetric solutions in Horava gravity
• Gravitomagnetic effects in Kerr-de Sitter space-time

Cited by in corpus (6)

• The Dark Matter Profiles in the Milky Way
• Systematic biases on galaxy haloes parameters from Yukawa-like gravitational potentials
• Galaxies Rotation Curves in the Grumiller's Modified Gravity
• Anisotropic Dark Matter Stars
• Spiral galaxies rotation curves in the Horava - Lifshitz gravity theory
• Constraints on Flows in Horava-Lifshitz Gravity by Classical Solutions