The cosmological evolution of primordial black holes (PBHs) is considered. A comprehensive view of the accretion and evaporation histories of PBHs across the entire cosmic history is presented, with focus on the critical mass holes. The critical mass of a PBH for current era evaporation is $M_{cr}\sim 5.1\times {10}^{14}$ g. Across cosmic time such a black hole will not accrete radiation or matter in sufficient quantity to hasten the inevitable evaporation, if the black hole remains within an average volume of the universe. The accretion rate onto PBHs is most sensitive to the mass of the hole, the sound speed in the cosmological fluid, and the energy density of the accreted components. It is not easy for a PBH to accrete the average cosmological fluid to reach $30M_{\odot }$ by $z\sim 0.1$, the approximate mass and redshift of the merging BHs that were the sources of the gravitational wave events GW150914 and GW151226. A PBH located in an overdense region can undergo enhanced accretion leading to the possibility of growing by many orders of magnitude across cosmic history. Thus, two merging PBHs are a plausible source for the observed gravitational wave events. However, it is difficult for isolated PBHs to grow to supermassive black holes (SMBHs) at high redshift with masses large enough to fit observational constraints.

考虑了原始黑洞（PBHs）的宇宙学演化。呈现了整个宇宙历史中PBH的吸积和蒸发历史的综合视图，重点是临界质量孔。当前时代蒸发的PBH的临界质量为${\mathrm{中号}}_{C\mathrm{[R}}〜5.1\times {10}^{14}$G。如果黑洞保持在宇宙的平均体积之内，那么在整个宇宙时间内，这样的黑洞将不会积聚辐射或足够数量的物质以加速不可避免的蒸发。PBH的吸积率对孔的质量，宇宙流体中的声速以及吸积成分的能量密度最敏感。PBH很难吸收平均宇宙流体$30{\mathrm{中号}}_{\odot }$ 通过 $ž〜0.1$，这是引力波事件GW150914和GW151226的合并BH的近似质量和红移。位于高密度区域的PBH可能会增加吸积，从而导致在整个宇宙历史中增长许多数量级的可能性。因此，两个合并的PBH是观察到的引力波事件的合理来源。但是，孤立的PBH很难在高红移下生长成质量足以满足观测约束的超大质量黑洞（SMBH）。