The expansion of the universe itself is not direct evidence of dark matter. However, observations of the expansion, such as the accelerated expansion discovered in the late 1990s, do suggest the presence of some unknown form of energy, often referred to as dark energy. Dark matter, on the other hand, is a different concept altogether. It is hypothesized to be an invisible and undetectable form of matter that does not interact with light or electromagnetic waves but exerts gravitational influence on visible matter, like stars and galaxies. Dark matter is invoked to explain the observed gravitational effects that cannot be accounted for by the visible matter in the universe. Although the expansion of the universe is not evidence for dark matter, studies of the cosmic microwave background radiation and observations of galaxy clusters do support the existence of dark matter.
