Echoes of inflationary first-order phase transitions in the CMB

Echoes of inflationary first-order phase transitions in the CMB

Blog Article

Cosmological phase transitions (CPTs), such as the Grand here Unified Theory (GUT) and the electroweak (EW) ones, play a significant role in both particle physics and cosmology.In this letter, we propose to probe the first-order CPTs, by detecting gravitational waves (GWs) which are generated during the phase transitions through the cosmic microwave background (CMB).If happened around the inflation era, the first-order CPTs may yield low-frequency GWs due to bubble dynamics, leaving imprints on the CMB.In contrast to the nearly scale-invariant primordial GWs caused by vacuum fluctuation, these bubble-generated GWs are sten jacket m scale dependent and have non-trivial B-mode spectra.If decoupled from inflaton, the EWPT during inflation may serve as a probe for the one after reheating where the baryon asymmetry could be generated via EW baryogenesis (EWBG).

The CMB thus provides a potential way to test the feasibility of the EWBG, complementary to the collider measurements of Higgs potential and the direct detection of GWs generated during EWPT.