Dr Katherine (Katie) Mack is a theoretical cosmologist specializing in the connections between astrophysics and particle physics. In modern cosmology, precision measurements of the cosmos on the largest scales can tell us about the nature of elementary particles and the structure of fundamental physical laws. Dr Mack is particularly interested in how the particle physics of dark matter, the mysterious invisible stuff that makes up most of the matter in the universe, can influence the evolution of stars and galaxies and what we might see in new observations as a result. She also works on topics related to the early universe, black holes, distant cosmic explosions known as fast radio bursts, and the formation of the first galaxies.