The Vev Flip-Flop: Dark Matter Decay between Weak Scale Phase Transitions

Understand

We propose a new alternative to the Weakly Interacting Massive Particle (WIMP) paradigm for dark matter.

• Rather than being determined by thermal freeze-out, the dark matter abundance in this scenario is set by dark matter decay, which is allowed for a limited amount of time just before the electroweak phase transition.
• More specifically, we consider fermionic singlet dark matter particles coupled weakly to a scalar mediator $S_3$ and to auxiliary dark sector fields, charged under the Standard Model gauge groups.
• Dark matter freezes out while still relativistic, so its abundance is initially very large.