  We consider a Bubble Expansion mechanism for the production of scalar dark
matter during a first-order phase transition in the early Universe. Seeking for
a dark matter energy density in agreement with observations, we study different
non-renormalizable interactions between the dark matter species and the field
undergoing the transition. The resulting relic abundance is shown to display a
strong dependence on the Lorentz boost factor associated to the bubble wall
motion, with this dependence becoming more significant the higher the dimension
of the non-renormalizable interaction. This allows for observational
compatibility across a wide range of dark matter masses and transition
temperatures, typically excluded in renormalizable scenarios. For a transition
around the electroweak scale, the associated gravitational wave spectrum is
also within the reach of future detectors.
