相关论文: Ultraviolet Freeze-in with a Time-dependent Inflat…
When dark matter particles only feebly interact with plasma constituents in the early universe, they never reach thermal equilibrium. As opposed to the freeze-out mechanism, where the dark matter abundance is determined at $T \ll M$, the…
We investigate a particle dark matter (DM) scenario where the DM interaction with the Standard Model are mediated by a leptophilic effective operator. Unlike conventional WIMP scenarios where thermal freeze-out occurs in a…
We study a novel dark matter production mechanism based on the freeze-in through semi-production, i.e. the inverse semi-annihilation processes. A peculiar feature of this scenario is that the production rate is suppressed by a small initial…
Recent study [1] has suggested that warm inflation may be realized with a minimal extension of the Standard Model by a single scalar inflaton field with an axion-like coupling to gluons. Motivated by this framework, we investigate the…
The aim of this paper is to determine an exact definition of the reheat temperature for a generic perturbative decay of the inflaton. In order to estimate the reheat temperature, there are two important conditions one needs to satisfy: (a)…
Dark matter, $X$, may be generated by new physics at the TeV scale during an early matter-dominated (MD) era that ends at temperature $T_R \ll {\rm TeV}$. Compared to the conventional radiation-dominated (RD) results, yields from both…
We present the supersymmetric extension of the unified model for inflation and Dark Matter studied in Ref. arXiv:1811.02302. The scenario is based on the incomplete decay of the inflaton field into right-handed (s)neutrino pairs. By…
We highlight the general scenario of dark matter freeze-out whilst the energy density of the universe is dominated by a decoupled non-relativistic species. Decoupling during matter domination changes the freeze-out dynamics, since the…
We investigate dark matter (DM) production in an early matter dominated era where a heavy long-lived particle decays to radiation and DM. In addition to DM annihilation into and thermal DM production from radiation, we include direct DM…
We present a detailed examination of thermalization after inflation for perturbative inflaton decay. Different interactions among particles in the plasma of inflaton decay products are considered and it will be shown that 2 -> 2 scatterings…
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…
In the presence of self-interactions, the post-inflationary evolution of the inflaton field is driven into the non-linear regime by the resonant growth of its fluctuations. The once spatially homogeneous coherent inflaton is converted into…
In this paper, we investigate the production of Majorana fermionic dark matter (DM) via the Higgs portal, considering both freeze-in and freeze-out mechanisms during and after the post-inflationary reheating phase. We assume that the…
The inclusion of a period of (effective) matter domination following inflation and prior to the onset of radiation domination has interesting and observable consequences for structure growth. During this early matter-dominated era (EMDE),…
The suppression of cosmological structure at small scales is a key signature of dark matter (DM) produced via freeze-in in the low-mass regime. We present a comprehensive analysis of its impact, incorporating recent constraints from Milky…
In standard cosmological scenarios, a heavy meta-stable field dominates the energy density of the universe after inflation. The dissipation of this field continuously sources high-energy particles. In general, the dissipation rate of this…
The reionization of hydrogen is closely linked to the first structures in the universe, so understanding the timeline of reionization promises to shed light on the nature of these early objects. In particular, transmission of Lyman alpha…
We consider the conditions for the decay products of perturbative inflaton decay to thermalize. The importance of considering the full spectrum of inflaton decay products in the thermalization process is emphasized. It is shown that the…
Light, weakly coupled sectors can retain information about the cosmological background in which they are produced. We study light axions produced during reheating and their contribution to dark radiation, $\Delta N_{\rm eff}$. We develop a…
The freeze-out of dark matter (DM) depends on the evolution of the DM temperature. The DM temperature does not have to follow the standard model one, when the elastic scattering is not sufficient to maintain the kinetic equilibrium. We…