相关论文: Impact of Primordial Ultracompact Minihaloes on th…

Primordial black holes (PBHs) are expected to accrete particle dark matter around them to form ultracompact minihalos (UCMHs), if the PBHs themselves are not most of the dark matter. We show that if most dark matter is a thermal relic, then…

Primordial black holes (PBHs) formed in the early Universe can accret dark matter particles due to gravity and form ultracompact minihalos (UCMHs). The theoretical researches and simulations have shown that the density profile of dark…

For a Gaussian spectrum of primordial density fluctuations, ultracompact minihalos (UCMHs) of dark matter are expected to be produced in much greater abundance than, e.g., primordial black holes. Forming shortly after matter-radiation…

In the mixed dark matter scenarios consisting of primordial black holes (PBHs) and weakly interacting massive particles (WIMPs), WIMPs can be accreted onto PBHs to form ultracompact minihalos (UCMHs) with a density spike in the early…

A new kind of dark matter structures, ultracompact minihalos (UCMHs) was proposed recently. They would be formed during the radiation dominated epoch if the large density perturbations are existent. Moreover, if the dark matter is made up…

Ultracompact Minihalos (UCMHs) have been proposed as a type of dark matter sub-structure seeded by large-amplitude primordial perturbations and topological defects. UCMHs are expected to survive to the present era, allowing constraints to…

We investigate the effect of non-evaporating primordial black holes (PBHs) on the ionization and thermal history of the universe. X-rays emitted by gas accretion onto PBHs modify the cosmic recombination history, producing measurable…

Compared with that of standard dark matter halos, the density profile of the recently proposed new kind of dark matter structure named ultracompact minihalos (UCMHs) is steeper and its formation time is earlier. If the dark matter is…

Primordial black holes (PBHs) form from large-amplitude initial density fluctuations and may comprise some or all of the dark matter. If PBHs have a broadly extended mass spectrum, or in mixed PBH-particle dark matter scenarios, the extreme…

If present in the early universe, primordial black holes (PBHs) will accrete matter and emit high-energy photons, altering the statistical properties of the {Cosmic Microwave Background (CMB)}. This mechanism has been used to constrain the…

We use cosmological hydrodynamic zoom-in simulations and semi-analytical models to study the effects of primordial black holes (PBHs) on first star formation. Our models self-consistently combine two competing effects: initial…

Events like inflation or phase transitions can produce large density perturbations on very small scales in the early Universe. Probes of small scales are therefore useful for e.g. discriminating between inflationary models. Until recently,…

We use semi-analytical models to study the effects of primordial black hole (PBH) accretion on the cosmic radiation background during the epoch of reionization ($z\gtrsim 6$). We consider PBHs floating in the intergalactic medium (IGM), and…

In the dark age of the universe, any exotic sources, e.g. the dark matter annihilation, which inject the energy into the intergalactic medium (IGM) will left some imprint on the 21cm background signal. Recently, one new kind of dark matter…

Much attention has been drawn to the recent discoveries by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) of merging intermediate mass black holes. Of particular interest is the possibility that the merger events…

Ultracompact minihalo (UCMH) is a special type of dark matter halo with a very steep density profile which may form in the early universe seeded by an overdense region or a primordial black hole. Constraints on its abundance give valuable…

The ultracompact minihalos could be formed during the earlier epoch of the universe. The dark matter annihilation within them is very strong due to the steep density profile, $\rho \sim r^{-2.25}$. The high energy electrons and positrons…

Motivated by the recent detection by WMAP of a large optical depth to Thomson scattering -- implying a very early reionization epoch -- we assess a scenario where the universe was reionized by `miniquasars' powered by intermediate-mass…

We investigate the impact of massive primordial black holes (PBHs; $m_{\rm BH}\sim 10^6~M_{\odot}$) on the star formation and first galaxy assembly process using high-resolution hydrodynamical simulations from $z = 1100$ to $z \sim 9$. We…

Ultracompact minihalos (UCMHs) have emerged as a valuable probe of the primordial power spectrum of density fluctuations at small scales. UCMHs are expected to form at early times in regions with ${\delta\rho/\rho \gtrsim 10^{-3}}$, and…