Abstract

Einstein’s curved spacetime theory for gravity rules supreme in the cosmos. Over the last century it has passed a variety of tests – all with flying colours. Still, our understanding remains incomplete. As the precision of our observations improve, we need a more detailed understanding on the theory side. Many of today’s questions – ranging from the violent dynamics of merging neutron stars emitting gravitational waves to the dark energy that causes the expansion of the universe to accelerate – demand a realistic description of matter. This inevitably brings us to consider fluid dynamics in the context of relativity. In this talk I will discuss the modern approach to relativistic fluid flows – drawing on examples from astrophysics and numerical simulations, and highlighting challenges that still need to be resolved.