A Naturally Minute Quantum Correction to the Cosmological Constant Descended from the Hierarchy

TL;DR

This paper shows how a tiny quantum correction to the cosmological constant can naturally emerge from a massive bulk fermion in the Randall-Sundrum model, linking fundamental hierarchy scales to dark energy without fine-tuning.

Contribution

It introduces a mechanism for naturally generating a minute quantum correction to the cosmological constant from a bulk fermion in the Randall-Sundrum model, maintaining stability.

Findings

Quantum correction can match observed dark energy scale.

Goldberger-Wise stabilization remains effective with a bulk fermion.

No fine-tuning needed for the fermion mass.

Abstract

We demonstrate that an extremely small but positive quantum correction, or the Casimir energy, to the cosmological constant can arise from a massive bulk fermion field in the Randall-Sundrum model. Specifically, a cosmological constant doubly descended from the Planck-electroweak hierarchy and as minute as the observed dark energy scale can be naturally achieved without fine-tuning of the bulk fermion mass. To ensure the stabilization of the system, we discuss two stabilization mechanisms under this setup. It is found that the Goldberger-Wise mechanism can be successfully introduced in the presence of a massive bulk fermion, without spoiling the smallness of the quantum correction.