HEP Theory Journal Club

Small Scale Challenges (and Solutions) for Lambda-CDM

Jonathan Cornell

McGill

The standard cosmological model of cold dark matter (CDM) and a cosmological constant has been remarkably successful at explaining the observed structure of the universe on large scales. However, on scales of the size of our Milky Way galaxy and below, there are discrepancies between N-body simulations of collisionless CDM and observations. While this could be caused by the neglect of baryonic effects in these simulations, it could also be a hint of the need to consider dark matter with modified properties from standard CDM. In this talk, I will review the major problems facing Lambda-CDM on small scales and then give a selective overview of the proposed solutions.