Jan 31: Constraining Extragalactic Magnetic Fields Using Astroparticle Physics and Cosmology

Andrey Saveliev (Immanuel Kant Baltic Federal University, Russia)

Abstract: Extragalactic Magnetic Fields (EGMFs) are one of the most important phenomena in astrophysics and cosmology, as a lot of information concerning the evolution and the present state of the Universe may be derived using them. In order to put constraints on EGMFs, one needs to consider a variety of their interactions with different environments: On the one hand they influence the propagation of charged particles, of which Ultra High Energy Cosmic Rays (UHECRs) and electromagnetic cascades initiated by TeV-gamma rays are of particular interest, since their trajectories are highly sensitive to EGMF parameters (such as their average field strength, correlation length, spectrum and helicity). On the other hand, EGMFs directly interact with the Intergalactic Medium (IGM), the understanding of which requires numerical and (semi-)analytical large-scale simulations. In case one assumes that they have been created in the Early Universe, one has also to consider cosmological aspects such as their impact on the Cosmic Microwave Background (CMB), which might be used to derive further constraints. In this talk we will discuss all these different methods for a coherent and comprehensive view on EGMFs.