Omega (sciences)

In cosmology, Omega (Ω) represents the density of the universe relative to a critical threshold needed for the universe to be flat. If Ω equals 1, the universe is perfectly balanced between eventual re-collapse and endless expansion. Values less than 1 indicate a universe that will expand forever, while values greater than 1 suggest it will eventually contract. Omega includes contributions from matter (both visible and dark matter), radiation, and dark energy. It’s a fundamental parameter in understanding the universe's shape, fate, and overall structure.