PRIMORDIAL BLACK HOLES, DIFFUSE GAMMA RADIATION OF THE UNIVERSE AND POSSIBLE NATURE OF DARK MATTER

Primordial Black Holes, Hawking Radiation and the Early Universe

Primordial Black Holes in an Accelerating Universe

General expressions are given for the generation of Primordial Black Holes (PBH) in a universe with a presently accelerated expansion due to a(n effective) cosmological constant. We give expressions both for a powerlaw scalefree primordial spectrum and for spectra which are not of that type. Specializing to the case of a pure cosmological constant Λ and assuming flatness, we show that a comolog...

Possible quantum instability of primordial black holes

Evidence for the possible existence of a quantum process opposite to the famous Hawking radiation (evaporation) of black holes is presented. This new phenomenon could be very relevant in the case of exotic multiple horizon Nariai black holes and in the context of common grand unified theories. This is clearly manifested in the case of the SO(10) GUT, that is here investigated in detail. The rem...

Primordial Black Holes and Hot Matter

Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. The possibility that a quasi-stationary shell of hot matter surrounds these black holes has recently been proposed and studied with relativistic Boltzmann transport equations and with relativisti...

Black Holes as Dark Matter

While the energy of the universe has been established to be about 0.04 baryons, 0.24 dark matter and 0.72 dark energy, the cosmological entropy is almost entirely, about (1−10), from black holes and only 10 from everything else. This identification of all dark matter as black holes is natural in statistical mechanics. Cosmological history of dark matter is discussed. [email protected]