Dr. Ryo Namba (McGill University)
"Magnetic fields of primordial origin" (ICRR & IPMU joint seminar)
Recent blazar observations provide growing evidence for the presence of magnetic fields in the extragalactic regions, where astrophysical processes are hardly responsible for their generation. While a natural speculation is to associate the production of large-scale magnetic fields to inflationary physics, it has been known that magnetogenesis solely from inflation is quite challenging due to the strong coupling problem and severe constraints from the CMB observations. In this talk I will discuss some mechanisms, successful/unsuccessful, for production of magnetic fields in the primordial universe and their evolution history up to today, as well as the constraints from theoretical consistencies and observational data.