Gravitational wave (GW) sirens are a group of methods used to constrain cosmological parameters and test the nature of gravity on large scales. In this talk I’ll introduce the main categories of GW sirens — bright, dark, and spectral —explaining how they differ, and how we work around the lack of further multimessenger events after GW170817.
We’ll take stock of where the current constraints from GW sirens stand. We’ll then explore how we can enhance these constraints through galaxy catalogue completion, i.e. reverse-engineering the distribution of faint galaxies missed by surveys.
Finally, we’ll look at what lies ahead in the short-term and long-term for cosmology using GW sirens. With tens of thousands (or more) of GW sources in hand, can we use GWs as ‘just another tracer’ of large-scale structure?