Jeans analysis in modified gravity

Abstract

MOdified Gravity (MOG) is a covariant modification of Einstein's general relativity. This theory is one of the current alternatives to dark matter models. We describe dynamics of collisionless self-gravitating systems in the context of MOG. By studying the weak field approximation of this theory, we derive the equations governing the dynamics of the self-gravitating systems. More specifically, we consider the Jeans instability for self-gravitating fluid and stellar systems, and derive new Jeans mass limit ${\tilde{M}}_J$ and wave-number ${\tilde{k}}_J$. Furthermore, considering the gravitational instability in star forming regions, we show that MOG has not a significant difference with general relativity on this astrophysical scale. However, at larger scales such as intergalactic space MOG may lead to different galaxy and structure formation processes.

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Cited by in corpus (5)

• Dynamical Instability of Spherical Star in $f(R,T)$ gravity
• On the stability of a galactic disk in modified gravity
• Testing modified gravity with dwarf spheroidal galaxies
• The phase space analysis of modified gravity (MOG)
• On the gravitational stability of the Maclaurin disk