Twin Higgs (TH) is the simplest model that incorporates a mirror matter sector. It naturally achieves a stable electroweak scale and matches the 125 GeV Standard Model (SM) Higgs mass without introducing coloured partners in LHC reach.
In the context of TH, the SM-like Higgs boson emerges as a pseudo-Nambu-Goldstone boson of the approximate global symmetry group. In my presentation, I will discuss the scalar phase transition in the Twin Higgs model and demonstrate that, under specific conditions, it can be strongly first-order. This transition may lead to the emission of a stochastic gravitational wave background and provide a framework for explaining the observed baryon asymmetry in the universe.