What crucial cooling mechanism present in modern stellar nurseries was absent during the universe's infancy?

Answer

Efficient radiation of thermal energy via dust grains and complex molecules

Modern star formation benefits from dust grains and molecules that efficiently radiate heat, allowing clouds to fragment. This mechanism was absent in the infancy of the universe, forcing the giant cloud to contract as one unit.

What crucial cooling mechanism present in modern stellar nurseries was absent during the universe's infancy?
Spacestarscosmologyformationastrophysicsnebulaestellar formation