Speaker
Robert Brandenberger
(McGill University)
Description
We propose a mechanism for the generation of magnetic fields on cosmological scales that is operative after recombination. An essential
ingredient is an instability of the electromagnetic field driven by an oscillating pseudo-scalar dark matter field, $\phi$, that is coupled to the electromagnetic field tensor via a $\phi F \wedge F$ term in the Lagrangian of axion-electrodynamics. We find that magnetic fields larger than the observational lower bounds can be generated on scales of $1 {\rm{Mpc}}$.
Author
Robert Brandenberger
(McGill University)
