inhomogeneous nucleosynthesis hypothesis

The inhomogeneous nucleosynthesis hypothesis is a modification of standard cosmological models. It suggests that in the universe's first microsecond, a quark-gluon plasma separated unevenly into protons and neutrons. This uneven distribution could have made nuclear reactions less efficient than standard calculations predict, potentially increasing the density of ordinary matter.1

However, calculations based on this hypothesis suggest that the conditions needed to produce the correct proportions of deuterium and helium-4 result in too much primordial lithium-7, which contradicts observations of ancient stars. Standard primordial nucleosynthesis, on the other hand, aligns well with observed proportions of hydrogen and helium in the universe, supporting the hot big bang theory.12