Related papers: Antimatter from Microscopic Black Holes
Hawking radiation from a non-extremal black hole is known to be approximately Planckian. The thermal spectrum receives multiple corrections including greybody factors and due to kinematical restrictions on the infrared and ultraviolet…
Black holes are extreme expressions of gravity. Their existence is predicted by Einstein's theory of general relativity and is supported by observations. Black holes obey quantum mechanics and evaporate spontaneously. Here it is shown that…
The high-energy particle production in the accretion flow onto black holes can be a key physics to explain the high-energy neutrino background. While the single-zone approximation has been commonly adopted in studies of the high-energy…
Primordial Black Holes (PBHs) are black holes that may have been created in the early Universe and could be as large as supermassive black holes or as small as the Planck scale. It is believed that a black hole has a temperature inversely…
The Hawking evaporation of small black holes formed by the collapse of dark matter at the center of neutron stars plays a key role in loosing the constraint on the mass of asymmetric bosonic non-interacting dark matter particles. Different…
Accreting black holes in galactic X-ray sources are surrounded by hot plasma. The innermost part of these systems is likely a corona with different temperatures for ions and electrons. In the so-called low-hard state, hot electrons…
A recently proposed model (arXiv:0903.2794) explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we…
The radiation from extreme Reissner-Nordstr\"{o}m black holes is computed by explicitly considering the collapse of a spherical charged shell. No neutral scalar radiation is found but there is emission of charged particles, provided the…
Gamma-ray bursts (GRBs) appear as the brightest transient phenomena in the Universe. The nature of the central engine in GRBs is a missing link in the theory of fireballs to their stellar mass progenitors. Here it is shown that rotating…
The possibility that the dark matter comprises primordial black holes (PBHs) is considered, with particular emphasis on the currently allowed mass windows at $10^{16}$ - $10^{17}\,$g, $10^{20}$ - $10^{24}\,$g and $1$ - $10^{3}\,M_{\odot}$.…
In a previous paper the spectrum of positrons produced by matter initially at rest falling onto a massive compact object was calculated. In this paper this calculation is generalized to obtain both the spectrum of in-flight positron…
Many models of dark matter contain more than one new particle beyond those in the Standard Model. Often heavier particles decay into the lightest dark matter particle as the Universe evolves. Here we explore the possibilities that arise if…
The evaporation of primordial black holes provides a promising dark matter production mechanism without relying on any non-gravitational interactions between the dark sector and the Standard Model. In theories of ``Large'' Extra Dimensions…
The origin of observed extremely high energy cosmic rays remains an astrophysical enigma. We show that a single evaporating primordial black hole should produce 8.5*10^14 particles over a 10^20 eV threshold. This emission results from…
A seven parameter family of five-dimensional black hole solutions depending on mass, two angular momenta, three charges and the asymptotic value of a scalar field is constructed. The entropy is computed as a function of these parameters…
Primordial black holes (PBHs) are the plausible candidates for the cosmological dark matter. Theoretically, PBHs with masses $M_{\rm PBH}$ in the range of $4\times10^{14}\sim 10^{17}\,{\rm g}$ can emit sub-GeV electrons and positrons…
Hawking evaporation of black holes in the early Universe is expected to copiously produce all kinds of particles, regardless of their charges under the Standard Model gauge group. For this reason, any fundamental particle, known or…
If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice-cap. We re-examine the prospects for observing such black holes with the…
Primordial black holes are produced in a minimal UV extension to the Higgs inflation with an included $R^2$ term. We show that for parameters consistent with Standard Model measurements and Planck observation results lead to $M_{\rm PBH}…
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…