Related papers: Axinos as Cold Dark Matter
Here we generally prove that the axion as a coherently oscillating scalar field acts as a cold dark matter in nearly all cosmologically relevant scales. The proof is made in the linear perturbation order. Compared with our previous proof…
A sterile neutrino with mass of several keV can account for cosmological dark matter, as well as explain the observed velocities of pulsars. We show that X-rays produced by the decays of these relic sterile neutrinos can boost the…
Some particle candidates for dark matter are reviewed in the light of recent experimental and theoretical developments. Models for massive neutrinos are discussed in the light of the recent atmospheric-neutrino data, and used to motivate…
We propose a new out-of-equilibrium production mechanism of light dark matter: resonance scanning. If the dark matter mass evolved in the early Universe, resonant production may have occurred for a wide range of light dark matter masses…
The cosmological scenario where the Peccei-Quinn symmetry is broken after inflation is investigated. In this scenario, topological defects such as strings and domain walls produce a large number of axions, which contribute to the cold dark…
The impact of a kination-dominated phase generated by a quintessential exponential model on the thermal abundance of gravitinos and axinos is investigated. We find that their abundances become proportional to the transition temperature from…
A cosmological scenario of a light axino and a lighter gravitino is presented. The most important consequence is that it can mimick the mixed dark matter (MDM) model of the large scale structure formation. The presence of axino and…
We review sterile neutrinos as possible Dark Matter candidates. After a short summary on the role of neutrinos in cosmology and particle physics, we give a comprehensive overview of the current status of the research on sterile neutrino…
This report is a brief review of the efforts to explain the nature of non-baryonic dark matter and of the studies devoted to the search for relic particles. Among the different dark matter candidates, special attention is devoted to relic…
We investigate the relic abundance of asymmetric Dark Matter where the asymmetric Dark Matter is non--thermally produced from the decay of heavier particles in addition to the usual thermal production. We discuss the relic density of…
The lightest supersymmetric particle, most likely the lightest neutralino, is one of the most prominent particle candidates for cold dark matter (CDM). We show that the primordial spectrum of density fluctuations in neutralino CDM has a…
Searches for dark matter decaying into photons constrain its lifetime to be many orders of magnitude larger than the age of the Universe. A corollary statement is that the abundance of any particle that can decay into photons over…
A sub-component of dark matter with a short collision length compared to a planetary size leads to efficient accumulation of dark matter in astrophysical bodies. We analyze possible neutrino signals from the annihilation of such dark matter…
If the dark matter of the Universe is made of sterile neutrinos with the mass in keV region they can be searched for with the help of X-ray satellites. We discuss the prospects of laboratory experiments that can be competitive and…
The possibility that the relics of quark hadron phase transition in the microsecond old universe, the quark nuggets, may well be reasonable candidates for cold dark matter is critically examined.
We investigate the clumping of cold dark matter (CDM) at small scales. If the CDM particle is the neutralino, we find that collisional damping during its kinetic decoupling from the radiation fluid and free streaming introduce a small-scale…
Extremely weakly interacting massive particles (E-WIMPs) are intriguing candidates for cold dark matter in the Universe. We review two well motivated E-WIMPs, an axino and a gravitino, and point out their cosmological and phenomenological…
Cosmological nucleosynthesis calculations imply that many of the baryons in the Universe must be dark. We discuss the likelihood that some of these dark baryons may reside in the discs or halos of galaxies. If they were in the form of…
This article summarizes the possible roles of neutrinos in cosmology, from the first three minutes onward. The fact that primordial neutrinos are about as numerous as the photons of the cosmological background radiation means that neutrino…
We investigate the prospects of indirect searches for supersymmetric neutralino dark matter. Relic neutralinos gravitationally accumulate in the Sun and their annihilations produce high energy neutrinos. Muon neutrinos of this origin can be…