Related papers: Dark Matter Freeze-out During Matter Domination
We consider the decay of a massive particle under the complete or partial domination of the kinetic energy density generated by a quintessential exponential model and we impose a number of observational constraints originating from…
If the early universe is dominated by an energy density which evolves other than radiation-like the normal Hubble-temperature relation $H\propto T^2$ is broken and dark matter relic density calculations in this era can be significantly…
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…
The role of the dilaton field and its coupling to matter may result to a dilution of Dark Matter (DM) relic densities. This is to be contrasted with quintessence scenarios in which relic densities are augmented, due to modification of the…
Progress in observational cosmology over the past five years has established that the Universe is dominated dynamically by dark matter and dark energy. Both these new and apparently independent forms of matter-energy have properties that…
We study the impact of an alternate cosmological history with an early matter-dominated epoch on the freeze-in production of dark matter. Such early matter domination is triggered by a meta-stable matter field dissipating into radiation. In…
Biswas et al. found that the thermal relic density of a dark matter particle freezing out while the universe's energy density is dominated by a non-standard extra component $\phi$, whose energy density redshifts faster than radiation, can…
Dark energy and dark matter are the dominant sources in the evolution of the late universe. They are currently only indirectly detected via their gravitational effects, and there could be a coupling between them without violating…
In the late Universe, and on cosmological scales, dark matter is conventionally assumed to be collisionless, as a consequence of the strong existing bounds on dark matter interactions at the Cosmic Microwave Background last-scattering…
Recent cosmological measurements favour additional relativistic energy density beyond the one provided by the three active neutrinos and photons of the Standard Model (SM). This is often referred to as "dark radiation", suggesting the need…
In models of Asymmetric Dark Matter (ADM) the relic density is set by a particle asymmetry in an analogous manner to the baryons. Here we explore the scenario in which ADM decouples from the Standard Model thermal bath during an early…
Recently, Valiviita et al. (2008) have reported a large-scale early-time instability in coupled dark energy and dark matter models. We take the same form of energy-momentum exchange and specialise to the case when the interaction rate is…
Models with dark energy decaying into dark matter have been proposed to solve the coincidence problem in cosmology. We study the effect of such coupling in the matter power spectrum. Due to the interaction, the growth of matter density…
The freeze-in mechanism describes the out-of-equilibrium production of dark matter (DM) particles via feeble couplings or non-renormalisable interactions with large suppression scales. In the latter case, predictions suffer from a strong…
We discuss a cosmology in which cold dark matter begins to decay into relativistic particles at a recent epoch (z < 1). We show that the large entropy production and associated bulk viscosity from such decays leads to an accelerating…
Considering that the universe is filled with the nonrelativistic matter and dark energy and each component is respectively satisfied with its conservation condition in the absence of their interaction, we give the change rate of the…
The properties of the dark matter that determine its thermal relic abundance can be very different from the dark matter properties today. We investigate this possibility by coupling a dark matter sector to a scalar that undergoes a phase…
Big-Bang nucleosynthesis (BBN) represents one of the earliest phenomena that can lead to observational constraints on the early Universe properties. It is well-known that many important mechanisms and phase transitions occurred before BBN.…
We study the possibility that dark energy decays in the future and the universe stops accelerating. The fact thatthe cosmological observations prefer an equation of state of dark energy smaller than -1 can be a signal that dark energy will…
An internally thermalized dark matter (DM) with only gravitational interaction with the standard model (SM) particles at low temperatures, may undergo number-changing self-scatterings in the early Universe, eventually freezing out to the…