Why General Theory of Relativity Allows the Existence of Only Extremal Black Holes

TL;DR

This paper demonstrates that general relativity predicts only extremal black holes with zero mass, implying that gravitational collapse continues indefinitely without forming an event horizon, thus avoiding information loss issues.

Contribution

The paper shows, through mathematical and physical analysis, that general relativity inherently requires black holes to have zero mass, extending the understanding of extremal black holes beyond supersymmetric string theories.

Findings

Black holes must have zero mass in general relativity.

Gravitational collapse continues infinitely without horizon formation.

No information loss problem arises for zero-mass black holes.

Abstract

Supersymmetric String theories find occurrences of extremal Black Holes with gravitational mass M=Q where Q is the charge (G=c=1). Thus, for the chargeless cases, they predict M=0. We show that General Theory of Relativity, too, demands a unique BH mass M=0. And we do this by considering the problem from various angles, both mathematically and physically. Our analysis may be understandable even to the readers not having sufficient background in GTR. Physically, this M=0 result means that, continued gravitational collapse indeed continues for infinite proper time as the system hopelessly tries to radiate its entire original mass energy to attain the lowest energy state M=0. Since no event horizon is formed, the problem of loss of information associated with creation of finite mass BHs or their evaporation ceases to exist.