Post-inflationary axions

The cosmic history of axions is most predictive when their associated (spontaneously broken) symmetry is restored in the post-inflationary early universe, with subsequent production of a network of cosmic axion strings. On the other hand, arguably the best motivated axions are those arising from extra dimensions, which are difficult to make compatible with the scenario above. In this talk, I explain how to reconcile the two from a theory point of view, and discuss phenomenological prospects.