Related papers: Spectator dark matter in non-standard cosmologies
We study the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Assuming that the dark matter obeys the collisional Boltzmann equation, we can derive analytical solutions of the global…
We investigate inflationary particle production associated with a spectator ultralight scalar field, which has been recently proposed as a plausible dark matter candidate. In this framework, we select the Starobinsky potential to drive the…
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 discuss structure formation in models with a spectator field in small-field inflation which accommodate a secondary period of inflation. In such models, subgalactic scale primordial fluctuations can be much suppressed in comparison to…
Growing Neutrino quintessence describes a form of dynamical dark energy that could explain why dark energy dominates the universe only in recent cosmological times. This scenario predicts the formation of large scale neutrino lumps which…
Modified dark matter (MDM) is a phenomenological model of dark matter, inspired by gravitational thermodynamics. For an accelerating Universe with positive cosmological constant ($\Lambda$), such phenomenological considerations lead to the…
We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…
A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…
We investigate the gravitational particle production from vacuum for a minimally coupled fermionic spectator field during a single-field inflationary phase. We observe that metric perturbations arising from the quantum fluctuations of a…
The impact of dark matter-neutrino ($\nu$DM) interactions on cosmological perturbations has regained attention, spurred by indications of non-zero couplings from high-multipole cosmic microwave background data, weak lensing, and…
Dark radiation (DR) appears as a new physics candidate in various scenarios beyond the Standard Model. While it is often assumed that perturbations in DR are adiabatic, they can easily have an isocurvature component if more than one field…
We consider a Bubble Expansion mechanism for the production of scalar dark matter during a first-order phase transition in the very early Universe. Seeking for a dark matter energy density in agreement with observations, we study different…
Dark matter (DM) which constitutes five-sixths of all matter is hypothesised to be a weakly interacting non-baryonic particle, created in the early stages of cosmic evolution. It can affect various cosmic structures in the Universe via…
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 emphasize the distinctive cosmological dynamics in multi-component dark matter scenarios and its impact in probing a sub-dominant component of dark matter. We find that the thermal evolution of the sub-component dark matter is…
The observed number of dwarf galaxies as a function of rotation velocity is significantly smaller than predicted by the standard model of cosmology. This discrepancy cannot be simply solved by assuming strong baryonic feedback processes,…
Despite the robust cosmological and astrophysical evidence confirming the existence of a non-baryonic matter component in the Universe, the underlying nature of Dark Matter (DM) remains a mystery. Among the several possible scenarios, light…
A new phenomenological dark energy model, originally associated to the large-scale structure formation and considered as a solution to the fine-tuning and coincidence problems related to the cosmological constant, was analyzed within the…
The universe has evolved through several phases as its various constituents dominated its energy content. Candidate dark matter particles may have undergone freeze-out during any such phase. While the standard freeze-out scenarios have been…
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…