Prospects for indirect detection of frozen-in dark matter

TL;DR

This paper explores the potential for indirect detection signals from non-thermally produced dark matter originating from a hidden sector that was populated through feeble interactions with the Standard Model, emphasizing the role of the hidden sector's temperature.

Contribution

It introduces a model where dark matter from a hidden sector can produce observable indirect signals despite weak couplings, highlighting the importance of the hidden sector's temperature at freeze-out.

Findings

Indirect signals depend on hidden sector temperature at freeze-out

Feebly-coupled mediators can produce detectable signals

Dark sector thermal history influences observational prospects

Abstract

We study observational consequences arising from dark matter (DM) of non-thermal origin, produced by dark freeze-out from a hidden sector heat bath. We assume this heat bath was populated by feebly-coupled mediator particles, produced via a Higgs portal interaction with the Standard Model (SM). The dark sector then attained internal equilibrium with a characteristic temperature different from the SM photon temperature. We find that even if the coupling between the DM and the SM sectors is very weak, the scenario allows for indirect observational signals. We show how the expected strength of these signals depends on the temperature of the hidden sector at DM freeze-out.