Density Perturbation of the Early Universe

The Cosmic Microwave Background, or CMB, is the radiation that spreads throughout the universe. The radiation we know as the CMB was created when the universe was around 380,000 years old. The universe has anisotropy, meaning it is not uniformly bright, it is also not uniform in temperature or density. Therefore, we can calculate the historic density perturbations based on the anisotropy of the CMB. The density perturbation is the average variance of densities throughout the universe. Using the simulation made by Dr. David Garrison and ran on the Singularity cluster at The University of Houston at Clear Lake, the density perturbation was calculated and tested. First, the density perturbation for when the universe was about 1 second old was calculated at 1.3e-4. Then using the code, tests were done to build a simulation where the universe was successfully developed, and the density perturbations resulted in the calculated value. These simulations started during the Electroweak Phase Transition when the universe was about 10e-12 seconds old. This brings us a better understanding of the universe and how it transitioned from radiation dominated to matter dominated. The perturbations also help solve the initial conditions of the universe when it was less than 1 second old.