The Charge of Electron, Weak Gravity Conjecture and Black Hole Evolution

The charge of an electron is vastly larger than its mass. We found that black hole evolution under Hawking evaporation is very sensitive to the value of electron charge. If the electron charge is weakened by a mere one order of magnitude, then the evolutionary paths of Reissner-Nordstr"om black holes under Hawking evaporation change substantially. In particular, weakening the electron charge causes some black holes that would otherwise immediately discharge towards Schwarzschild limit to first evolve towards extremality before turning around. We discuss the possible connections between the weak gravity conjecture, the cosmic censorship conjecture, and black hole evolution.