Understanding the connection between the matter content of the universe and its thermal history is a major challenge in cosmology. The detection of gravitational waves (GW) from binary black hole mergers at LIGO has invigorated efforts to scope the universe in a broad temperature range and answer the question: is there new physics at the electroweak scale? The electroweak phase transition (EWPT) in beyond the Standard Model (BSM) theories could be strongly first order, possibly via complex multi-step transitions, and thereby explain baryogenesis and in turn the baryon asymmetry of the universe.

Such a transition would also source a stochastic GW background that propagates freely to us from the early universe (cf. top figure). Its signal is expected in the millihertz band of the Laser Interferometer Space Antenna (LISA), a space-based detector of three spacecraft trailing the Earth around the Sun (cf. animation) that ESA plans to launch in 2035. Turning such a measurement into a statement about particle physics requires precise predictions of the phase transition thermodynamics.

DRalgo is an algorithmic implementation that constructs an effective high-temperature theory for generic models. The Mathematica package automates the matching of 4d thermal field theories to their 3d EFTs at next-to-leading order and, since its latest update, of higher-dimensional operators at one loop.

WallGo is an open source code for the computation of the bubble wall velocity and bubble wall width in first-order cosmological phase transitions. The main WallGo Python package determines the wall velocity and width by solving the scalar field(s) equation of motion, the Boltzmann equations and energy-momentum conservation for the fluid velocity and temperature.