Collider and Gravitational Wave Complementarity in Exploring the Singlet
  Extension of the Standard Model
  We present a dedicated complementarity study of gravitational wave and
collider measurements of the simplest extension of the Higgs sector: the
singlet scalar augmented Standard Model. We study the following issues: (i) the
electroweak phase transition patterns admitted by the model, and the proportion
of parameter space for each pattern; (ii) the regions of parameter space that
give detectable gravitational waves at future space-based detectors; and (iii)
the current and future collider measurements of di-Higgs production, as well as
searches for a heavy weak diboson resonance, and how these searches interplay
with regions of parameter space that exhibit strong gravitational wave signals.
We carefully investigate the behavior of the normalized energy released during
the phase transition as a function of the model parameters, address subtle
issues pertaining to the bubble wall velocity, and provide a description of
different fluid velocity profiles. On the collider side, we identify the subset
of points that are most promising in terms of di-Higgs and weak diboson
production studies while also giving detectable signals at LISA, setting the
stage for future benchmark points that can be used by both communities.
