Claude-Andre Faucher Giguere (Northwestern University/CIERA)

The Universe on a computer: Cosmological simulations of galaxy formation

Cosmological simulations start from Big Bang initial conditions and simulate a representative volume of the Universe to the present time. They follow the dynamics of dark matter, stars, and gas and have been very successful at explaining the large-scale structure that we measure in the distributions of galaxies and intergalactic gas across cosmic time. Due to finite resolution and an incomplete set of physical processes, these simulations have however struggled to produce realistic galaxies on small scales. I will discuss our group’s efforts to dramatically improve the predictive power of cosmological simulations by explicitly resolving the internal structure of simulated galaxies and the “feedback” processes from stars and black holes that affect the formation and evolution of galaxies (the FIRE project). I will highlight some of the computational limitations of our current work, and emphasize how progress has not only been enabled by improved computational tools but also by a better understanding of the most important physics.