Neutrinos from primordial black holes

Abstract

The emission of particles from black holes created in the early Universe has detectable astrophysical consequences. The most stringent bound on their abundance has been obtained from the absence of a detectable diffuse flux of 100 MeV photons. Further scrutiny of these bounds is of interest as they, for instance, rule out primordial black holes as a dark matter candidate. We here point out that these bounds can, in principle, be improved by studying the diffuse cosmic neutrino flux. Measurements of near-vertical atmospheric neutrino fluxes in a region of low geomagnetic latitude can provide a competitive bound. The most favorable energy to detect a possible diffuse flux of primordial black hole origin is found to be a few MeV. We also show that measurements of the diffuse ν τ flux is the most promising to improve the existing bounds deduced from gamma-ray measurements. Neutrinos from individual black hole explosions can be detected in the GeV-TeV energy region. We find that the kilometer-scale detectors, recently proposed, are able to establish competitive bounds.

Prospects for observations of high-energy cosmic tau neutrinos

“…The situation is quite similar to the prompt atmospheric ν τ flux calculation; the result is basically a rescaling of the prompt ν µ flux from the decay of charmed D's and results in a negligibly small ν τ flux for the energies under discussion [15,16].…”

High temperature matter and neutrino spectra from microscopic black holes

“…Such a study is especially important in the context of high energy neutrino detectors under construction or planned for the future. Previous notable studies in this area have been carried out by MacGibbon and Webber [6] and by Halzen, Keszthelyi and Zas [7], who calculated the instantaneous and time-integrated spectra of neutrinos arising from the decay of quark and gluon jets.…”

Lorentz andCPTinvariance violation in high-energy neutrinos

“…Such possibilities include annihilating or decaying dark matter or topological defects [69], Hawking radiating primordial black holes [70], or the interactions of ultra-high energy neutrinos with the cosmic neutrino background via the Zburst mechanism [71]. For a review of sources of high-energy neutrinos and other aspects of high-energy neutrino astronomy, see Ref.…”