3 problems

Let an extremal black hole be a charged black hole with a degenerate horizon, and let the charge-to-mass ratio of an emitted particle measure its charge relative to its mass. Weak…

Let $M$ and $Q$ denote the mass and charge of an evaporating charged black hole or white hole, respectively. Extremality is approached as $Q/M$ tends to $1$. Near-extremal evaporat…

Weak gravity conjecture. Such a theory should always contain a stable superextremal particle; equivalently, there should exist a stable particle of mass $m$ and electric charge $q$…