A new probe of primordial magnetic fields at high redshift

          @misc{ scivideos_PIRSA:16060011,
            doi = {10.48660/16060011},
            url = {https://pirsa.org/16060011},
            author = {Gluscevic, Vera},
            keywords = {Cosmology},
            language = {en},
            title = {A new probe of primordial magnetic fields at high redshift},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2016},
            month = {jun},
            note = {PIRSA:16060011 see, \url{https://scivideos.org/pirsa/16060011}}
          }
          

Abstract

I will present a novel method for probing extremely weak large-scale magnetic fields in the intergalactic medium prior to the epoch of reionization. This method relies on the effect of spin alignment of hydrogen atoms in a cosmological setting, and on the effect of magnetic precession of the atoms on the statistics of the 21–cm brightness–temperature fluctuations. It is intrinsically sensitive to magnetic fields weaker than 10^{-19} Gauss in physical units, and thus has a potential to reach many orders of magnitude below the current constraints on primordial magnetic fields. I will discuss the physical mechanism, lay out the estimator formalism that enables searches with future 21-cm tomographic surveys, and present forecasts for detecting magnetic fields in the high-redshift universe using this method.