Abstract
We study the production of large-scale (∼Mpc) magnetic fields in inflationary Universe models. The magnetic fields produced are uninterestingly small unless the conformal invariance of the electromagnetic field is broken. Once the conformal invariance is broken, a mechanism akin to ‘‘superadiabatic amplification’’ can operate and lead to sizable primeval magnetic fields. We consider three ways of breaking the conformal invariance: through gravitational couplings of the photon; through the coupling of the photon to a charged massless, nonconformally invariant scalar field; and through the anomalous coupling of the photon to axions. The primeval magnetic fields which result can have astrophysically interesting strengths, but are very model dependent.
- Received 21 September 1987
DOI:https://doi.org/10.1103/PhysRevD.37.2743
©1988 American Physical Society