To study the mysterious dark sector we use powerful simulations on state-of-the-art high-performance computers, run at Argonne and elsewhere. By developing specialized codes for these supercomputers, and by comparing their results to observations from deep surveys of the sky, we aim to answer some of the most fundamental questions in physics: What is dark matter made of? What is the nature of dark energy? Does general relativity need to be modified? What is the nature of primordial fluctuations from which all the structure in the Universe came to be?

Computational cosmology is an exciting collaborative endeavor bringing together astrophysicists, high-energy physicists, computer scientists, and applied mathematicians and statisticians. Each group provides unique perspectives and contributions on how to overcome the challenges posed by the ​“Dark Universe.”