Freeze-in self-interacting dark matter in warped extra dimension

TL;DR

This paper proposes a MeV-scale, self-interacting dark matter candidate arising naturally in warped extra dimensions, which can address small-scale structure issues with minimal parameter assumptions.

Contribution

It introduces a classically scale-invariant scalar singlet as dark matter within warped extra dimensions, highlighting its natural emergence and parameter space.

Findings

Dark matter candidate with feeble Higgs portal coupling (~10^{-10})

Self-interaction coupling (~0.1) can alleviate small-scale problems

Parameter space is large but predicted by few fundamental parameters

Abstract

A classically scale-invariant scalar singlet can be a MeV-scale dark matter, with a feeble Higgs portal coupling at $\mathcal{O}(10^{-10})$. Besides, an $\mathcal{O}(0.1)$ self-interaction coupling could further serve to alleviate the small-scale problems in the Universe. We show that, such a dark matter candidate can naturally arise in the warped extra dimension, with the huge span of parameter space predicted well within $\mathcal{O}(1)$ fundamental parameters.