Size Gap for Zero Temperature Black Holes in Semiclassical Gravity

TL;DR

This paper demonstrates a size gap for zero temperature static spherically symmetric black holes in semiclassical gravity with conformally invariant fields, showing certain sizes are forbidden depending on quantum field content.

Contribution

It reveals a size gap for zero temperature black holes in semiclassical gravity and derives general properties of black holes in classical and semiclassical theories.

Findings

A size gap exists for zero temperature black holes.

The size gap depends on the types and numbers of quantum fields.

General properties of black holes are derived in classical and semiclassical contexts.

Abstract

We show that a gap exists in the allowed sizes of all zero temperature static spherically symmetric black holes in semiclassical gravity when only conformally invariant fields are present. The result holds for both charged and uncharged black holes. By size we mean the proper area of the event horizon. The range of sizes that do not occur depends on the numbers and types of quantized fields that are present. We also derive some general properties that both zero and nonzero temperature black holes have in all classical and semiclassical metric theories of gravity.