Enhancing the cross-correlations between magnetic fields and scalar perturbations through parity violation

Understand

One often resorts to a non-minimal coupling of the electromagnetic field in order to generate magnetic fields during inflation.

• The coupling is expected to depend on a scalar field, possibly the same as the one driving inflation.
• At the level of three-point functions, such a coupling leads to a non-trivial cross-correlation between the perturbation in the scalar field and the magnetic field.
• This cross-correlation has been evaluated analytically earlier for the case of non-helical electromagnetic fields.