相关论文: Geometrical origin for the compaction function for…
For a variety of on-going and planned gravitational-wave (GW) experiments, we study expected constraints on the fraction ($f_{\rm PBH}$) of primordial black holes (PBHs) in dark matter by evaluating the energy-density spectra of two kinds…
Primordial black-hole formation depends exponentially on the far tail of the primordial curvature-perturbation distribution. That sensitivity makes the small-scale collapse problem a sharp probe of primordial non-Gaussianity. We study the…
Constant-rate inflation, including ultra-slow-roll as a special case, has been widely applied to the formation of primordial black holes with significant deviation from the standard slow-roll conditions at both the growing and decaying…
While large numbers of supermassive black holes have been detected at z>6, their origin is still essentially unclear. Numerical simulations have shown that the conditions for the classical direct collapse scenario are very restrictive and…
The holographic complexity of a static spherically symmetric black hole, defined as the volume of an extremal surface, grows linearly with time at late times in general relativity. The growth comes from a region at a constant transverse…
The power spectrum of the scalar-tensor inflation with a quadratic form Ricci scalar coupling function $\Omega(\phi)=1- 2\phi/\phi_c+(1+\delta^2)(\phi/\phi_c)^2$ can be enhanced enough to produce primordial black holes and generate…
Sufficiently large scalar perturbations in the early Universe can create over-dense regions that collapse into primordial black holes (PBH). This process is accompanied by the emission of scalar-induced gravitational waves (SIGW) that…
Chaotic inflation is inconsistent with the observational constraint at 68\% CL. Here, we show that the enhancement mechanism with a peak function in the noncanonical kinetic term not only helps the chaotic model $V(\phi)=V_0\phi^{1/3}$…
Primordial black holes may arise through ultra slow-roll inflation. In this work we study a toy model of ultra slow-roll inflation with a shallow dip. The ultra slow-roll stage enhances the curvature perturbations and thus the primordial…
The primordial black hole (PBH) formation is studied in light of the inflating curvaton. The typical scale of the PBH formation is determined by curvaton inflation, which may generate PBH with $10^{14}\mathrm{g}\le M_\mathrm{PBH}\le…
The final ringdown phase in a coalescence process is a valuable laboratory to test General Relativity and potentially constrain additional degrees of freedom in the gravitational sector. We introduce here an effective description for…
We define compactness of a gravitational lens as the scaled closest distance of approach (i.e., $r_0/M$) of the null geodesic giving rise to an image. We model forty supermassive dark objects as Schwarzschild lenses and compute compactness…
The mass function of primordial black holes created through the near-critical gravitational collapse is calculated in a manner fairly independent of the statistical distribution of underlying density fluctuation, assuming that it has a…
We study the generation of primordial black holes (PBH) in a single field inflection point model of inflation wherein the effective potential is expanded up to the sextic order and the inversion symmetry is imposed such that only even…
We discuss a novel window to probe the origin of our universe via the mass functions of primordial black holes (PBHs). The mass functions of PBHs are simply estimated using the conventional Press-Schechter formalism for two paradigms of…
We investigate an inflationary model with a non-minimal derivative coupling, where the coupling function contains both constant and periodic components. On large scales, the model is in excellent agreement with the latest…
The primordial black hole (PBH) is an effective candidate for dark matter. In this work, the PBH abundance $f$ is calculated in peak theory, with one or two perturbations in the inflaton potential. We construct an antisymmetric perturbation…
If primordial black holes (PBHs) form directly from inhomogeneities in the early Universe, then the number in the mass range $10^5 -10^{12}M_{\odot}$ is severely constrained by upper limits to the $\mu$ distortion in the cosmic microwave…
Primordial black holes (PBHs) are dark matter candidates that span broad mass ranges from $10^{-17}$ $M_\odot$ to $\sim 100$ $M_\odot$. We show that the stochastic gravitational wave background can be a powerful window for the detection of…
The semiclassical geometry of charged black holes is studied in the context of a two-dimensional dilaton gravity model where effects due to pair-creation of charged particles can be included in a systematic way. The classical mass-inflation…