Modifying dark matter indirect detection signals by thermal effects at freeze-out

Abstract

We present an extension of the standard model, containing a fermion dark matter candidate and two real scalar singlets, where the observed dark matter abundance is produced via freeze-out before the electroweak phase transition. We show that, in this case, the dark matter annihilation channels determining its freeze-out are different from those producing indirect detection signals. We present a benchmark model where the indirect annihilation cross section differs from the freeze-out one. The model also has a gravitational wave signature due to the first-order electroweak phase transition.

Variations on the vev flip-flop: instantaneous freeze-out and decaying dark matter

“…These finite-temperature effects are known to cause important phenomena in the development of the universe, such as the electroweak phase transition (EWPT). Recently there has been interest in understanding the impact of finite temperature effects in mechanisms of DM production [8][9][10][11][12][13][14][15][16][17].…”

Black holes at cosmic dawn in the redshifted 21cm signal of HI

“…Bean and Magueijo 2002) and as the sources that may boost the EDGES HI absorption (e.g. Hektor, A. et al 2018). Besides, PBHs have been proposed to be the LIGO-Virgo BHs of 30-40 M⊙ (e.g.…”

Dark matter transient annihilations in the early Universe

“…There have been prior studies on the effects cosmological evolution have on DM or scalar mediator mass, stability, interaction couplings, and annihilation channels [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. In our scenario, we, for the first time, focus on the vector mediator whose mass is significantly affected during the freeze-out.…”