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

Abstract

The theory of evolution of the early universe predicts the formation of black holes of different mass. Depending on the physical processes, black holes can be formed with masses up to 1027 g. Because of the Hawking effect of quantum evaporation of black holes, black holes with masses over 1015 g have survived to our time. The aim of this work is to calculate the intensity of gamma radiation from the primordial black holes, to explain the diffuse gamma spectrum of the Universe’s radiation from them in the range of 10-100 MeV, and to estimate their contribution to dark matter of the Universe. Methodology. The intensity of radiation from an ensemble of black holes is calculated by using an approximation in the form of the δ-function for the radiation of the absolutely black body. Results. It is shown that if the function of the masses of primordial black holes is N(M) = K · M-γ, the intensity of Hawking’s radiation is I(ν) ~ νγ. Since the background radiation of the Universe in the range of quantum energies 10-100 MeV has the form of I(ν) ~ ν-1,3 MeV/cm2 MeV ⋅ ster, then N(M) = K ⋅ M1,3. In this range there emit primary black holes with masses of 1015g and sizes of an electron. Research implications. It is shown that the extrapolation of the resulting distribution of masses to the values of 5·1021g allows one to explain the observed mass of dark matter in the Universe. At the same time, the concentration of these black holes with masses comparable to the masses of asteroids is such that there may be hundreds of them in the solar system.

Keywords

• cosmology
• primordial black holes
• Hawking radiation
• dark matter