The past decade has seen two breakthroughs in particle physics and cosmology. The LIGO and VIRGO observatories detected gravitational waves from merging black holes, and a few years earlier the Large Hadron Collider discovered the Higgs boson, a big missing piece in the Standard Model of particle physics – yet questions remain about how the Higgs 'turned on'. Attention is now turning towards future gravitational wave observatories, such as the space-based LISA mission. Depending on how the Higgs boson switched on, gravitational waves could have been produced at frequencies to which LISA is sensitive. Indeed if the Higgs underwent a phase transition, it would have produced a signal which LISA could detect, if it is strong enough. In this project we will investigate LISA's ability to detect such a phase transition, both by improving predictions of the gravitational wave signal for various scenarios – and studying LISA's ability to extract such a signal from background noise.

2022

2026