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

Abstract

A classically scale-invariant scalar singlet can be a MeV-scale dark matter, with a feeble Higgs portal coupling at O(10−10). Besides, an 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 O(1) fundamental parameters.