Fermionic current and Schwinger effect in de Sitter spacetime

TL;DR

This paper investigates the fermionic Schwinger effect in two-dimensional de Sitter spacetime, introducing a semiclassical method for pair production and analyzing the induced current under a constant electric field.

Contribution

It presents a new semiclassical approach to compute fermionic pair production in curved spacetime and compares results with bosonic cases, highlighting differences in current behavior.

Findings

Semiclassical method agrees with Bogoliubov results for constant fields

No strong current observed for small electric fields in fermions

Differences between fermionic and bosonic current responses

Abstract

We study the fermionic Schwinger effect in two dimensional de Sitter spacetime. To do so we first present a method to semiclassically compute the number of pairs created per momentum mode for general time dependent fields. In addition the constant electric field is studied in depth. In this case solutions for the Dirac equation can be found and the number of pairs can be computed using the standard Bogoliubov method. This result is shown to agree with the semiclassical one in the appropriate limit. The solutions are also used to compute the expectation value of the induced current. Comparing these results to similar studies for bosons we find that while the results agree in the semiclassical limit they do not generally. Especially there is no occurrence of a strong current for small electric fields.