Fermion Production: Implications for Gauge Fields and Inflation

This lecture discusses the production of fermions in the context of gauge fields during inflation. It begins by examining the dynamics of fermion production in a helical gauge field background, highlighting the role of electric and magnetic fields. The instructor explains how fermions are accelerated in this background and how their production can inhibit further gauge field generation. The Dirac equation is introduced to analyze the quantized energy levels in constant magnetic fields and the time-dependent energy levels in electric fields. The lecture also covers the implications of fermion back-reaction on gauge field production, emphasizing the non-linear nature of the system and the challenges in finding stationary solutions. The discussion extends to the implications for late universe scenarios, including magnetogenesis and baryogenesis, and the potential for new avenues in understanding cosmic phenomena. The instructor concludes by addressing open questions and the need for further research in this area, particularly regarding the interplay between fermions and gauge fields in cosmological models.