Vachaspati Tanmay
Physics Department, Arizona State University, Tempe, AZ 85287, United States of America.
Rep Prog Phys. 2021 Jun 17;84(7). doi: 10.1088/1361-6633/ac03a9.
A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound ∼10G. Such magnetic fields can play an important astrophysical role, for example at cosmic recombination and during structure formation, and also provide crucial information for particle physics in the early Universe. Magnetic fields with significant energy density could have been produced at the electroweak phase transition. The evolution and survival of magnetic fields produced on sub-horizon scales in the early Universe, however, depends on the magnetic helicity which is related to violation of symmetries in fundamental particle interactions. The generation of magnetic helicity requires new CP violating interactions that can be tested by accelerator experiments via decay channels of the Higgs particle.
各种观测结果对星系际尺度上相干的磁场施加了纳高斯级别的上限，而耀变体观测表明下限约为10高斯。这样的磁场可以发挥重要的天体物理作用，例如在宇宙复合时期和结构形成期间，并且还为早期宇宙中的粒子物理学提供关键信息。具有显著能量密度的磁场可能在电弱相变时产生。然而，早期宇宙中在亚视界尺度上产生的磁场的演化和存续取决于磁螺旋度，磁螺旋度与基本粒子相互作用中的对称性破缺有关。磁螺旋度的产生需要新的CP破坏相互作用，这种相互作用可以通过希格斯粒子的衰变通道由加速器实验进行检验。
