Gravitational Waves from First-Order Phase Transitions Assisted by Temperature-Enhanced Scatterings

Abstract: Scatterings whose cross sections increase as the cosmic temperature decreases, known as temperature-enhanced scatterings, can have a significant impact on the thermal effective potential of scalar fields responsible for driving cosmological first-order phase transitions. In this work, we systematically investigate how the inclusion of temperature-dependent corrections to the effective potential affects key phase transition parameters, including the nucleation temperature, latent heat release, and inverse duration parameter. These modifications influence both the strength and duration of the phase transition, which in turn determine the properties of the resulting stochastic gravitational wave (GW) background. Employing semi-analytic computational methods, we evaluate the GW spectra generated under these conditions and compare our predictions with the projected sensitivities of forthcoming detectors such as LISA, DECIGO, and BBO. Our analysis demonstrates that temperature-enhanced scatterings can substantially strengthen the phase transition and produce GW signals that lie within the reach of future observational facilities. This study highlights the importance of temperature-dependent microphysical processes in shaping early Universe cosmological signatures.