The Dawn of FIMP Dark Matter: A Review of Models and Constraints

By N. Bernal, M. Heikinheimo, Tommi Tenkanen, K. Tuominen, V. Vaskonen. 2017

460 citations recorded by the source corpus.

We present an overview of scenarios where the observed Dark Matter (DM) abundance consists of Feebly Interacting Massive Particles (FIMPs), produced nonthermally by the so-called freeze-in mechanism. In contrast to the usual freeze-out scenario, frozen-in FIMP DM interacts very weakly with the particles in the visible sector and never attained thermal equilibrium with the baryon–photon fluid in the early Universe. Instead of being determined by its annihilation strength, the DM abundance depends on the decay and annihilation strengths of particles in equilibrium with the baryon–photon fluid, as well as couplings in the DM sector. This makes frozen-in DM very difficult but not impossible to test. In this review, we present the freeze-in mechanism and its variations considered in the literature (dark freeze-out and reannihilation), compare them to the standard DM freeze-out scenario, discuss several aspects of model building, and pay particular attention to observational properties and general testability o...

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/544829571c7f6016d79b8e2d5fec2d6a36d4ed32

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Citations in the corpus

Detection of sub-MeV dark matter with three-dimensional Dirac materials (2017, background): “There are many ways to fix the observed DM abundance in these theories, including asymmetric DM [29–31], freeze-in [32,33], strong dynamics [34–36], kinematic thresholds [37], and various nonstandard thermal histories [38–43], to name a few.”
Sterile neutrino Dark Matter (2018, background): “ see eqns. (18) and (24). Sterile neutrinos that have no other interactions than the -suppressed weak interaction (3) fall into the category of feebly interacting massive particles (FIMPs), cf. e.g. [424]. The MSM [36,37] is an example for a specic models in which this possibility is realised. It ha”
Gravitational production of vector dark matter (2020, background): “Thermal freeze-out and other DM production mechanisms [5] are theoretically appealing, however there has been no sign of DM interactions with the SM in a variety of experiments thus far, apart from its gravitational interactions.”
micrOMEGAs5.0 : Freeze-in (2018, background): “The corresponding Boltzmann equations for FIMPs are also known and have been solved in several models, for a review see also [44].”
WIMP dark matter candidates and searches—current status and future prospects (2017, background): “ed with respect to, e.g., Majorana DM. A more detailed discussion can be found in, e.g., Ref. [89]. Among various other possible ways to deal with too large values of h˙ annv M˝li f one recent review [79]. { 11 { should also mention an increased expansion rate of the Universe prior to, and around, t”
Light dark matter: Models and constraints (2017, background): “The relic abundance can be fixed in a variety of ways, including via particle-antiparticle asymmetry as in asymmetric DM [11–13], strong dynamics [14,15], freeze-in [16,17], or other thermal histories for example [18–24].”