ΛCDM in a courtroom

The cosmological constant Λ, and its generalization as Dark Energy, makes up roughly 70% of the present-epoch universe and has been part of the dominant ΛCDM cosmological paradigm for more than a quarter of a century. It has been put on trial by recent measurements of galaxy clustering, Type Ia supernovae, and the cosmic microwave background. In this Perspective we evaluate the strength of the evidence for a constant Λ, versus Dynamical Dark Energy (DDE) in the light of recent developments. We also assess what the future holds both for our Universe and our understanding of its most mysterious component.