Dense strongly interacting matter
Quantum Chromodynamics (QCD) is the quantum field theory describing the strong interaction between the fundamental building blocks of nucleons, quarks and gluons. While its microscopic structure is deceptively simple, non-perturbative many-body dynamics give rise to various complex macroscopic phenomena. A tried and tested way to better understand these phenomena is to expose matter to extreme conditions. In this lecture we will explore how QCD matter behaves under extreme density. This includes spatially modulated regimes, where crystalline or even more exotic phases are possible. In addition to fundamental aspects, we will discuss how such phases could be discovered through heavy-ion collisions.