Strong electroweak phase transitions without collider traces

We discuss the question if the upcoming generation of collider and low-energy experiments can successfully probe the nature of the electroweak phase transition. In particular, we are interested in phase transitions strong enough for electroweak baryogenesis or even for a production of gravitational radiation observable by the Big Bang Observer. As an explicit example, we present an analysis in a singlet extension of the Standard Model. We focus on the region in parameter space where the model develops no significant deviation in its low energy phenomenology from the Standard Model. Nevertheless, this class of models can develop a very strong phase transition.