Relaxion Dark Matter

TL;DR

This paper proposes that the relaxion field, originally introduced to address the hierarchy problem, can also serve as a viable dark matter candidate in the keV mass range, linking two fundamental issues in physics.

Contribution

It introduces a novel connection between the relaxion mechanism and dark matter, demonstrating the relaxion's dual role in solving the hierarchy problem and explaining dark matter abundance.

Findings

Relaxion can account for dark matter in the keV mass range.

The relaxation mechanism during inflation involves particle production friction.

The model is phenomenologically viable for dark matter.

Abstract

We highlight a new connection between the Standard Model hierarchy problem and the dark matter sector. The key piece is the relaxion field, which besides scanning the Higgs mass and setting the electroweak scale, also constitutes the observed dark matter abundance of the universe. The relaxation mechanism is realized during inflation, and the necessary friction is provided by particle production. Using this framework we show that the relaxion is a phenomenologically viable dark matter candidate in the keV mass range.