Simulations of extragalactic magnetic fields and of their observables
  The origin of extragalactic magnetic fields is still poorly understood. Based
on a dedicated suite of cosmological magneto-hydrodynamical simulations with
the ENZO code we have performed a survey of different models that may have
caused present-day magnetic fields in galaxies and galaxy clusters. The
outcomes of these models differ in cluster outskirts, filaments, sheets and
voids and we use these simulations to find observational signatures of
magnetogenesis. With these simulations, we predict the signal of extragalactic
magnetic fields in radio observations of synchrotron emission from the cosmic
web, in Faraday Rotation, in the propagation of Ultra High Energy Cosmic Rays,
in the polarized signal from Fast Radio Bursts at cosmological distance and in
spectra of distant blazars. In general, primordial scenarios in which
present-day magnetic fields originate from the amplification of weak (<nG)
uniform seed fields result more homogeneous and relatively easier to observe
magnetic fields than than astrophysical scenarios, in which present-day fields
are the product of feedback processes triggered by stars and active galaxies.
In the near future the best evidence for the origin of cosmic magnetic fields
will most likely come from a combination of synchrotron emission and Faraday
Rotation observed at the periphery of large-scale structures.
