Cosmic Microwave Background (CMB) fluctuations, often referred to as CMB anisotropies or fluctuations, are tiny variations in the temperature and energy density of the cosmic microwave background radiation. The CMB is the faint, uniform glow of microwave radiation permeating the universe, which is a remnant of the hot and dense early universe, shortly after the Big Bang.
CMB fluctuations are essential in understanding the structure and evolution of the universe. They result from quantum fluctuations in the early universe and are responsible for the observed variations in temperature across the CMB sky. These fluctuations are incredibly small, representing temperature differences at the level of millionths of a degree.
By studying CMB fluctuations, astronomers and cosmologists can gain valuable insights into the early universe’s conditions, such as the density and distribution of matter. They have played a crucial role in confirming the Big Bang theory and shedding light on the formation of cosmic structures like galaxies and galaxy clusters. Precise measurements of these fluctuations have provided strong support for the current cosmological model, helping to unravel the mysteries of the cosmos.
