Black Holes and Black Strings on Cylinders

TL;DR

This paper reviews a new ansatz for describing non-extremal charged dilatonic branes with a transverse circle, enabling the construction of solutions that break translational symmetry and have higher entropy than black strings.

Contribution

Introduces a novel coordinate-based ansatz that simplifies equations of motion and applies to both charged and neutral black objects on cylinders.

Findings

Existence of neutral solutions breaking translational invariance.

Solutions with larger entropy than uniform black strings.

Applicability to charged and neutral dilatonic branes.

Abstract

We review the recently discovered ansatz that describes non-extremal charged dilatonic branes of string/M-theory with a transverse circle. The ansatz involves a new coordinate system that interpolates between the spherical and cylindrical case, and reduces the equations of motion to a set of equations on one unknown function of two variables. The function is independent of the charge, so that the ansatz can also be used to construct neutral black holes on cylinders and near-extremal charged dilatonic branes with a transverse circle. The construction enables us to argue that, for sufficiently large mass, there exists a neutral solution that breaks translational invariance in the circle direction, and has larger entropy than that of the neutral black string of the same mass.