Covariant Vacuum Polarizations on de Sitter Background

Understand

We derive covariant expressions for the one loop vacuum polarization induced by a charged scalar on de Sitter background.

• Two forms are employed: one in which two covariant derivatives act on de Sitter invariant basis tensors multiplied by scalar structure functions, and the other in which four covariant derivatives act on a single basis tensor times a structure function.
• The second representation permits the correction to dynamical photons to be expressed as a surface integral, which raises the important question of what sorts of effects can be absorbed into corrections of the initial state.
• Results are obtained for charged, minimally coupled scalars which are either massless or else light.