Energy density evolution of primordial black holes(PBHs) due to quantum gravitational tunneling effect in the very early Universe is calculated for the four cases of GUTs(grand unified theories) (SM, SUSY SM, SUSY SU(5), SU(5)). For the three of them (SM, SUSY SM, SUSY SU(5)), it is confirmed that there are a considerable amount of PBHs and so it may give a firm support to Lindley's paper(1981) in which he tried to solve the baryon asymmetry problem. It is shown that the formation of PBHs increases the cosmic scale factor R and decreases the total energy density ρt ρt faster than in the usual radiation dominated era.

• Hwang C.O.(Department of Astronomy, Seoul National University)
• Hyun J.J.(Department of Astronomy, Seoul National University)