511 keV galactic line from first-order phase transitions and primordial black holes

Po-Yan Tseng, Yu-Min Yeh

Hawking evaporation of primordial black hole (PBH), with mass $3\times 10^{-17}\lesssim M_{\mathrm{PBH}}/M_{\odot }\lesssim 7\times 10^{-17}$ and fractional abundance $0.01 \lesssim f_{\…