Physical renormalization condition for de Sitter QED

TL;DR

This paper introduces a new renormalization condition called maximal subtraction for de Sitter QED, which modifies the behavior of induced currents and resolves issues like IR hyperconductivity.

Contribution

The paper proposes the maximal subtraction scheme as a novel renormalization condition that alters the behavior of vacuum currents in de Sitter QED.

Findings

Maximal subtraction enforces exponential suppression in massive charged particle limit.

It aligns scalar and spinor currents' asymptotic behaviors.

It removes IR hyperconductivity and yields finite currents for massless fermions.

Abstract

We considered a new renormalization condition for the vacuum expectation values of the scalar and spinor currents induced by a homogeneous and constant electric field background in de Sitter spacetime. Following a semiclassical argument, the condition named maximal subtraction imposes the exponential suppression on the massive charged particle limit of the renormalized currents. The maximal subtraction changes the behaviors of the induced currents previously obtained by the conventional minimal subtraction scheme. The maximal subtraction is favored for a couple of physically decent predictions including the identical asymptotic behavior of the scalar and spinor currents, the removal of the infrared (IR) hyperconductivity from the scalar current, and the finite current for the massless fermion.