Rotating Black Holes, Closed Time-Like Curves, Thermodynamics, and the Enhancon Mechanism

TL;DR

This paper investigates supersymmetric rotating black holes in five dimensions, demonstrating how the enhancon mechanism prevents violations of thermodynamics and the formation of closed time-like curves, thus supporting their non-manufacturability in such systems.

Contribution

It explores the role of the enhancon mechanism in protecting black holes from thermodynamic violations and closed time-like curves in a D-brane framework with K3 compactification.

Findings

Enhancon loci prevent Second Law violations.

Charges can lead to closed time-like curves without enhancon intervention.

Enhancon mechanism does not eliminate all closed time-like curves.

Abstract

We reconsider supersymmetric five dimensional rotating charged black holes, and their description in terms of D-branes. By wrapping some of the branes on K3, we are able to explore the role of the enhancon mechanism in this system. We verify that enhancon loci protect the black hole from violations of the Second Law of Thermodynamics which would have been achieved by the addition of certain D-brane charges. The same charges can potentially result in the formation of closed time-like curves by adding them to holes initially free of them, and so the enhancon mechanism forbids this as well. Although this latter observation is encouraging, it is noted that this mechanism alone does not eliminate closed time-like curves from these systems, but is in accord with earlier suggestions that they may not be manufactured, in this context, by physical processes.