A black-hole minimum mass

Abstract

We discuss two alternative derivations of black-hole minimum mass: one gives a value ∼ the Planck mass (∼10−5 g); while the other, derived from a «hadron-barrier» limitation to black-hole size, gives a value ∼1015 g. We introduce the concept of maximum particle acceleration, following a discussion by Caianiello, and suggest that this be related to black-hole surface gravity. Since minimum black hole mass corresponds to maximum surface gravity, a new limit to black-hole mass arises. We find that the minimum mass thereby obtained is ∼1014 g, which excludes the Planck mass as being too small to be a physically realistic value.