Related papers: Updated Constraints on Primordial Black Hole Evapo…
We derive the strongest constraint on the fraction of dark matter that can be composed of low mass primordial black holes by using the observation of the Galactic Center 511 keV gamma-ray line. Primordial black holes of masses $\lesssim$…
Primordial black holes are under intense scrutiny since the detection of gravitational waves from mergers of solar-mass black holes in 2015. More recently, the development of numerical tools and the precision observational data have…
The 511 keV gamma emission from the galactic core may originate from a high concentration ($\sim 10^{22}$) of primordial black holes (PBHs) in the core each of whose Hawking radiation includes $\sim 10^{21}$ positrons per second. The PBHs…
Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are…
Primordial black holes may form in the early Universe, for example from the collapse of large amplitude density perturbations predicted in some inflationary models. Light black holes undergo Hawking evaporation, the energy injection from…
An excess of 511 keV photons has been detected from the central region of the Milky Way. It has been suggested that the positrons responsible for this signal could be produced through the Hawking evaporation of primordial black holes. After…
Primordial black holes (PBHs) are able to produce light dark matter (DM) particles via Hawking radiation, and yield a flux of boosted DM that can be probed at underground DM direct detection experiments. We analyze both galactic and…
Primordial black holes can represent all or most of the dark matter in the window $10^{17}-10^{22}\,$g. Here we present an extension of the constraints on PBHs of masses $10^{13}-10^{18}\,$g arising from the isotropic diffuse gamma ray…
As space expands, the energy density in black holes increases relative to that of radiation, providing us with motivation to consider scenarios in which the early universe contained a significant abundance of such objects. In this study, we…
The observed 511 keV line from the Galactic Bulge is a real challenge for theoretical astrophysics: despite a lot of suggested mechanisms, there is still no convincing explanation and the origin of the annihilated positrons remains unknown.…
The galactic 511 keV gamma-ray line has been observed since 1970's, and was identified as the result of electron-positron annihilation, but the origin of such positrons is still not clear. Apart from the astrophysical explanations, the…
We revisit the constraints on evaporating primordial black holes (PBHs) from the isotropic X-ray and soft gamma-ray background in the mass range $10^{16}-10^{18}$ g. We find that they are stronger than usually inferred due to two neglected…
The non-observation of Hawking radiation from primordial black holes of $10^{16}$g sets a conservative strong bound on their cosmological abundance. We revisit this bound and show how it can be improved (both in mass reach and strength) by…
Light, asteroid-mass primordial black holes, with lifetimes in the range between hundreds to several millions times the age of the universe, are well-motivated candidates for the cosmological dark matter. Using archival COMPTEL data, we…
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…
The energy injection through Hawking evaporation has been used to put strong constraints on primordial black holes as a dark matter candidate at masses below $10^{17}\,\rm{g}$. However, Hawking's semiclassical approximation breaks down at…
Hawking evaporation of primordial black hole (PBH), with mass $3\times 10^{-17} \lesssim M_{\rm PBH}/M_\odot \lesssim 7\times 10^{-17}$ and fractional abundance $0.01 \lesssim f_{\rm PBH} \lesssim 0.5$, well reproduces 511 keV gamma-ray…
Primordial black holes are a possible component of dark matter, and a most promising way of investigating them is through the product of their Hawking evaporation. As a result of this process, any species lighter than the Hawking…
Limits on the dark matter fraction of small mass primordial black holes from Hawking radiation are predominantly derived from the assumption of a Schwarzschild black hole evaporating. However, astrophysical black holes are usually much more…
We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range $10^{-5}\text{--}10^{50}$ g. Those smaller than $\sim 10^{15}$ g would have evaporated by now due to Hawking…