相关论文: Scattering versus Forbidden Decay in Dark Matter F…
The connection between a hidden nonthermal sector and a thermal plasma can be established by a light thermal fermion mediator. When the fermion mediator is much lighter than the hidden species, kinematically forbidden decay of the mediator…
We study the importance of a frozen-in dark matter production regime, where the dark matter particle is produced via kinematically forbidden decays that arise from significant thermal correction to the mass a mediator particle in the…
We examine and point out the importance of a regime of dark matter production through the freeze-in mechanism that results from a large thermal correction to a decaying mediator particle mass from hot plasma in the early Universe. We show…
We examine a scenario for freeze-in production of dark matter, which occurs due to the large thermal correction to the mass of a decaying mediator particle present in the thermal bath of the early Universe. We show that the decays, which…
If the dark matter is produced in the early universe prior to Big Bang nucleosynthesis, a modified cosmological history can drastically affect the abundance of relic dark matter particles. Here, we assume that an additional species to…
We study the free-streaming effect in a light freeze-in dark matter model. Naturally in the dark sector one can find dark matter related coupling, and such coupling may induce dark matter self-scattering. In case that such scattering is…
Predictivity of many non-thermal dark matter (DM) models is marred by the gravitational production background. This problem is ameliorated in models with lower reheating temperature $T_R$, which allows for dilution of gravitationally…
We present a thorough analysis of the sequential freeze-in mechanism for dark matter production in the early universe. In this mechanism the dark matter relic density results from pair annihilation of mediator particles which are themselves…
We explore a new mechanism for reproducing the Dark Matter (DM) abundance: scatterings of one DM particle on light Standard Model particles. Strong bounds on its decays can be satisfied if DM undergoes freeze-in and has a mass around or…
We study warm Higgs portal dark matter (DM) in the framework of freeze-in at stronger coupling. This scenario assumes that the Standard Model thermal bath temperature has always been relatively low, which suppresses dark matter production.…
Dark matter may be coupled to dark radiation: light degrees of freedom that mediate forces between dark sector particles. Cosmological constraints favor dark radiation that is colder than Standard Model radiation. In models with fixed…
We consider a model of two-component dark matter based on a hidden $U(1)_D$ symmetry, in which relic densities of the dark matter are determined by forbidden channels and thermal freeze-out. The hidden $U(1)_D$ symmetry is spontaneously…
Dark matter produced from thermal freeze-out is typically restricted to have masses above roughly 1 MeV. However, if the couplings are small, the freeze-in mechanism allows for production of dark matter down to keV masses. We consider dark…
We revisit dark-matter production through freeze-in and freeze-out by solving the Boltzmann equations at the level of the phase-space distribution $f(p,t)$. Using the $2\to2$ annihilation and the $1\to2$ decay processes for illustration, we…
The thermal relic density of dark matter is conventionally set by two-body annihilations. We point out that in many simple models, $3 \to 2$ annihilations can play an important role in determining the relic density over a broad range of…
Exponential suppression or commonly known as the Boltzmann suppression in the number density of dark matter is the key ingredient for creating chemical imbalance prior to the usual thermal freeze-out. A degenerate/quasi-degenerate dark…
We explore ways of creating cold keV-scale dark matter by means of decays and scatterings. The main observation is that certain thermal freeze-in processes can lead to a cold dark matter distribution in regions with small available phase…
At the tail of its velocity distribution, cold dark matter (DM) can annihilate at finite temperature to states heavier than itself. We explore the possibility that DM freezeout is dictated by these "forbidden annihilations" at the…
Recently, one of the present authors noticed a stimulated emission process of bosonic dark matter via the two-body decay of a mother particle in a thermal plasma similar to the operation principle of a laser in 2301.08735. In this paper, we…
Dark matter (DM) could couple to particles in the Standard Model (SM) through a light vector mediator. In the limit of small coupling, this portal could be responsible for producing the observed DM abundance through a mechanism known as…