Related papers: Fermion emission in a two-dimensional black hole s…
Fermion production in an external Coulomb field on de Sitter expanding universe is studied. The amplitude and probability of pair production in an external Coulomb field are computed and the cases of large/small values of the expansion…
Dark matter coupled solely gravitationally can be produced through the decay of primordial black holes in the early universe. If the dark matter is lighter than the initial black hole temperature, it could be warm enough to be subject to…
In this paper, using Hamilton-Jacobi method, we discuss the tunnelling of fermions when the dual influence of quantum gravity and the deformation of a parameterized black hole is taken into account. With the influence of the generalized…
We investigate the tunnelling of spin 1/2 particles through event horizons. We first apply the tunnelling method to Rindler spacetime and obtain the Unruh temperature. We then apply fermion tunnelling to a general non-rotating black hole…
Sterile neutrinos, fermions with no standard model couplings [SU(2) singlets], are predicted by most extensions of the standard model, and may be the dark matter. I describe the nonthermal production and linear perturbation evolution in the…
We considered the behaviour of Dirac fermion modes in the background of Euclidean dilaton black hole with an Abelian Higgs vortex passing through it. Fermions were coupled to the fields due to the superconducting string model. The case of…
The thermal balance between the black hole and surrounding thermal radiation is an interesting topic. The primordial black hole is a type of black hole formed in the early universe, especially during the thermal radiation period of the…
We investigate how dark energy affects atom-field interaction. To this end, we consider acceleration radiation of a freely falling atom close to a Schwarzschild black hole (BH) in the presence of dark energy characterized by a positive…
Primordial black holes (PBHs), produced in the early Universe, can source a stochastic background of induced gravitational waves (GWs) and provide a non-thermal origin for dark matter (DM). We investigate DM production in a PBH-dominated…
We study a scenario in which the baryon asymmetry is created through Hawking radiation from primordial black holes via a dynamically-generated chemical potential. This mechanism can also be used to generate the observed dark matter…
In this work we find static black hole solutions in the context of the two-dimensional dilaton gravity, which is modified by the addition of an $R^2$ term. This term arises from the one-loop effective action of a massive scalar field in its…
In models with extra dimensions, a black hole evaporates both in the bulk and on the visible brane, where standard model fields live. The exact emissivities of each particle species are needed to determine how the black hole decay proceeds.…
Recent analytic calculations on the rate for the production of a pair of massive fermions in $e^+ e^-$ annihilation plus real or virtual radiation of a pair of massless fermions are discussed. The contributions for real and virtual…
Two-dimensional dilaton gravity coupled to a Klein-Gordon matter field with a quartic interaction term is considered. The theory has a classical solution which exhibits black hole formation by a soliton. The geometry of black hole induced…
In this paper we study fermion perturbations in four dimensional black holes of string theory, obtained either from a non-extreme configuration of three intersecting five-branes with a boost along the common string or from a non-extreme…
Consider a particle sitting at a fixed position outside of a stable black hole. If the system is heated up, the black hole horizon grows and there should exist a critical temperature above which the particle enters the black hole interior.…
We explore the formation process of a black hole (BH) through the pair-instability collapse of a rotating Population III very massive star in axisymmetric numerical relativity. As the initial condition, we employ a progenitor star which is…
In the framework of communication theory, we analyse the gedanken experiment in which beams of quanta bearing information are flashed towards a black hole. We show that stimulated emission at the horizon provides a correlation between…
Black holes with masses of $\rm 10^6-10^9~M_{\odot}$ dwell in the centers of most galaxies, but their formation mechanisms are not well known. A subdominant dissipative component of dark matter with similar properties to the ordinary…
We consider spherical collapse in the Randall-Sundrum type II model and estimate the critical over density for black hole formation in the radiation dominated era. It is found that when (density)$^{2}$-term is dominant in the modified…