Related papers: Frozen-in fermionic singlet dark matter in non-sta…
In the standard model of cosmology, the present evolution of the Universe is determined by the presence of two components of unknown nature. One of them is referenced as ``dark matter'' to justify the fact that it behaves cosmologically…
The origin of dark matter as a thermal relic offers a compelling way in which the early universe was initially populated by dark matter. Alternative explanations typically appear exotic compared to the simplicity of thermal production.…
Indirect searches of Dark Matter (DM), in conjugation with `missing track searches' at the collider seem to confine SU(2)$_L$ fermion triplet DM (FTDM) mass within a narrow range around 1 TeV. The canonical picture of the pure FTDM is in…
The negative pressure accompanying gravitationally-induced particle creation can lead to a cold dark matter (CDM) dominated, accelerating Universe (Lima et al. 1996) without requiring the presence of dark energy or a cosmological constant.…
Thermal freeze-out is a prominent example of dark matter (DM) production mechanism in the early Universe that can yield the correct relic density of stable weakly interacting massive particles (WIMPs). At the other end of the mass scale,…
According to the second law of thermodynamics, the arrow of time points to an ever increasing entropy of the Universe. However, exactly how the entropy evolves with time and what drives the growth remain largely unknown. Here, for the first…
Dark matter drops out of kinetic equilibrium with standard model particles when the momentum-transfer rate equals the expansion rate. In a radiation-dominated universe, this occurs at essentially the same time as dark matter kinetically…
Motivated by the fact that, so far, the whole body of evidence for dark matter is of gravitational origin, we study the decays of dark matter into Standard Model particles mediated by gravity portals, i.e., through nonminimal gravitational…
We study a mechanism through which the cosmic dark matter density can be explained simultaneously with the observed baryon asymmetry of the Universe. At the core of our proposal lie the out-of-equilibrium scattering processes of bath…
We investigate nucleosynthesis and element formation in the early universe in the framework of higher dimensional cosmology. For this purpose we utilize a previous solution of the present author, which may be termed as the generalized…
For non-relativistic thermal dark matter, close-to-threshold effects largely dominate the evolution of the number density for most of the times after thermal freeze-out, and hence affect the cosmological relic density. A precise evaluation…
Light dark photons are subject to various plasma effects, such as Debye screening and resonant oscillations, which can lead to a more complex cosmological evolution than is experienced by conventional cold dark matter candidates.…
We study the dilution of dark matter (DM) relic density caused by the electroweak first-order phase transition (FOPT) in the singlet extension models, including the singlet extension of the standard model (xSM), of the two-Higgs-doublet…
Both scalar and vector dark matter can be produced during a cosmological first order phase transition if the dark matter is coupled to the field undergoing the transition. Both kinds of particle are also produced by the plasma through the…
From flow without dissipation of energy to the formation of vortices when placed within a rotating container, the superfluid state of matter has proven to be a very interesting physical phenomenon. Here we present the key mechanisms behind…
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…
The Froggatt-Nielsen (FN) mechanism provides an attractive way of generating the determined fermion mass hierarchy and quark mixing matrix elements in the Standard Model (SM). Here we extend it by coupling the FN field, the flavon, to a…
Particle creation (or annihilation) mechanisms, described by either quantum field theoretical models, or by the thermodynamics of irreversible processes, play an important role in the evolution of the early Universe, like, for example, in…
We investigate the production and freeze-out of dark matter with a constant thermally averaged cross-section in a generic bouncing universe framework. Our result shows that, there is a novel avenue that dark matter is produced thermally and…
We investigate the possibility of \emph{freeze-in} dark matter production and baryogenesis via leptogenesis in a $\psi'$SM model, which is an $E_6$ extension of the Standard Model, featuring a residual $U(1)_{\psi'}$ gauge symmetry. This…