Adiabatic regularization for spin-1/2 fields

Understand

We extend the adiabatic regularization method to spin-1/2 fields.

• The ansatz for the adiabatic expansion for fermionic modes differs significantly from the WKB-type template that works for scalar modes.
• We give explicit expressions for the first adiabatic orders and analyze particle creation in de Sitter spacetime.
• As for scalar fields, the adiabatic method can be distinguished by its capability to overcome the UV divergences of the particle number operator.