Galaxy formation by mock gravity with dust?

Abstract

Absorbing dust immersed in an isotropic radiation field experiences an attractive force, 'mock gravity', due to mutual shadowing, and the resulting mock gravitational instability can lead to clumping of dust and gas. The effects of mock gravity in the pre-Galactic universe are studied here, including imcomplete coupling of dust and gas, finite gas pressure, radiative drag both by the radiation that causes the instability and by the cosmic microwave background radiation, and finite albedo of dust, all of which have been neglected in the previous calculations. It is concluded that the radiation field implied by the submillimeter background is not strong enough to cause clumping of gas on scales of interest.