cosmic structure formation

Cosmic structure formation describes how the universe's matter organized itself into stars, galaxies, and larger structures over billions of years. Initially, tiny fluctuations in the density of matter caused some regions to be slightly more gravitationally attractive. These denser areas pulled in surrounding matter, growing over time. As the universe expanded and cooled after the Big Bang, gravity helped these regions clump together, forming the complex patterns we observe today—galaxies, clusters, and vast cosmic web filaments. This process is a gradual build-up driven by gravity acting on the initial small irregularities in the universe’s early matter distribution.