Do naked singularities generically occur in generalized theories of gravity?

TL;DR

This paper demonstrates that in certain generalized theories of gravity, specifically in Einstein-Maxwell-dilaton systems with a cosmological constant, naked singularities naturally form during gravitational collapse, challenging the cosmic censorship conjecture.

Contribution

It introduces a new mechanism for naked singularity formation in superstring-inspired gravity models where static black holes are absent.

Findings

Naked singularities occur during gravitational collapse in the studied system.

The system lacks static black hole solutions.

Field equations break down at the singularities.

Abstract

A new mechanism for causing naked singularities is found in an effective superstring theory. We investigate the gravitational collapse in a spherically symmetric Einstein-Maxwell-dilaton system in the presence of a pure cosmological constant "potential", where the system has no static black hole solution. We show that once gravitational collapse occurs in the system, naked singularities necessarily appear in the sense that the field equations break down in the domain of outer communications. This suggests that in generalized theories of gravity, the non-minimally coupled fields generically cause naked singularities in the process of gravitational collapse if the system has no static or stationary black hole solution.