Relaxion dark matter

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 kilo-electron-volt mass range.