PT2GWFinder : A package for cosmological first-order phase transitions and gravitational waves

The detection of gravitational waves from binary black hole and neutron star mergers by ground-based interferometers, as well as the evidence for a gravitational wave background from pulsar timing array experiments, has marked a new era in astrophysics and cosmology. These experiments also have great potential for discovering new physics through gravitational wave detection. One of the most motivated sources of gravitational waves that can be realized only within a beyond-the-Standard-Model framework is first-order phase transitions. In this work we release PT2GWFinder , a Mathematica package designed to compute phase transition parameters and the gravitational wave power spectrum for an arbitrary scalar theory exhibiting a first-order phase transition, in scenarios where a single scalar acquires a vacuum expectation value. PT2GWFinder performs the phase tracing, computes the bounce profile and action using FindBounce , calculates the relevant temperatures and phase transition parameters, and finally evaluates the gravitational wave spectrum. Additionally, it offers a user-friendly interface with DRalgo , which enables the computation of the dimensionally reduced effective potential in the high-temperature regime. This work includes a user manual and two models that demonstrate the capability and performance of PT2GWFinder . As a supplement, for one of these models we obtain the bounce solution and action analytically in the thin-wall approximation and demonstrate excellent agreement with the numerical approach. Program summary Program title : PT2GWFinder CPC Library link to program files: https://doi.org/10.17632/s69t25dw2j.1 Developer’s repository link : https://github.com/finshky/PT2GW Licensing provisions : GNU General Public License 3 Programming language : Mathematica Nature of problem : Search and characterization of cosmological first-order phase transitions, computation of the generated gravitational wave spectra. Solution method : Construction of the Euclidean bounce action function, using FindBounce , and application of integral criteria to determine the transition temperatures. Restrictions : Mathematica version 13 or above, applicable to single-field models.