Dark Radiation Isocurvature from Cosmological Phase Transitions

Explore cutting-edge physics research in this seminar presentation from Rutgers University physicist Peizhi Du, examining how cosmological first-order phase transitions relate to physics beyond the Standard Model. Delve into the generation of large-scale isocurvature in dark radiation through non-thermal first-order phase transitions and their potential observability in the Cosmic Microwave Background (CMB). Learn about derived constraints on Delta N_eff from phase transitions using CMB and Baryon Acoustic Oscillations (BAO) data, which demonstrate stronger effects than those from adiabatic initial conditions. Understand how the non-Gaussian origin of dark radiation perturbations could enable CMB non-Gaussianity searches to place significant bounds on Delta N_eff.