The problem is this: children can learn that our sun is one of hundreds of billions of stars in the Milky Way and that the Milky Way is one of many billions of galaxies in the observable universe. As always, understanding brings questions; for galaxies these include: How do they form? What are their internal dynamics? Do galaxies interact and collide? What controls their distribution in space? Astonishingly, the best answers to these questions require the cosmos to have a “skeleton” of dark matter roughly four times more massive than all of the gas, dust and stars in the universe combined; dark matter drives the dynamics responsible for galaxy formation and evolution.
Interacting galaxies — these massive spiral galaxies contain billions of stars, but the gravitational fields associated with luminous matter alone cannot account for their dynamics.
Dark matter is thus a dramatic success for cosmology and a profound challenge for particle physics: it explains key properties of the universe and makes well-verified predictions but its fundamental composition is mysterious and entirely unknown. We will investigate the dynamics and observable signatures of ultralight (or axion) dark matter, a promising scenario with the capacity to resolve key challenges that stand in the way of a detailed understanding of dark matter dynamics, with broad implications for both the evolution of galaxies and theories of fundamental particle physics.
We will be taking on a new PhD student post-doc to support this project.