In the early universe, why were inhomogeneities in the distribution of normal matter much smaller than the inhomogeneities in the dark matter?
A) Normal matter is pushed away by supernova explosions.
B) Magnetic fields smoothed the distribution of charged particles in the normal matter but not in dark matter.
C) Dark matter particles were more massive and cooled off before normal matter, thus dark matter fluctuations had a longer time over which to grow.
D) Dark matter was 10 times more massive than normal matter.
E) Radiation pressure affected normal matter but not dark matter.

Question

Quizplus · Accepted Answer

Radiation pressure affected normal matter but not dark matter, smoothing out inhomogeneities in the normal matter distribution while dark matter, which does not interact with radiation, was unaffected.

In the Early Universe, Why Were Inhomogeneities in the Distribution