Inflation from Charged Scalar and Primordial Magnetic Fields?

Understand

A model of inflation is presented where the inflaton field is a complex scalar field coupled to a U(1) gauge field.

• Due to the axial symmetry of the potential, the inflation is driven by the radial direction while the angular field is gauged by U(1).
• Due to the coupling of the inflaton to the gauge field, a time dependent mass term for the gauge field is generated dynamically and conformal invariance is broken.
• We study whether a significant amount of primordial magnetic fields can be generated during inflation by allowing a time-dependent U(1) gauge kinetic coupling.