A General Black String and its Microscopics

TL;DR

This paper constructs the most general black string solution in five-dimensional supergravity using dualities, exploring its extremal limits, microscopic entropy, and relation to black rings and BTZ black holes.

Contribution

It introduces a comprehensive black string solution with five parameters, unifying various extremal and non-extremal cases, and connects it to black rings and microscopic CFT descriptions.

Findings

The solution encompasses supersymmetric and non-supersymmetric extremal limits.

The decoupling limit yields a BTZ black hole times a sphere.

Microscopic entropy matches the CFT predictions.

Abstract

Using G2(2) dualities we construct the most general black string solution of minimal five-dimensional ungauged supergravity. The black string has five independent parameters, namely, the magnetic one-brane charge, smeared electric zero-brane charge, boost along the string direction, energy above the BPS bound, and rotation in the transverse space. In one extremal limit it reduces to the three parameter supersymmetric string of five-dimensional minimal supergravity; in another extremal limit it reduces to the three parameter non-supersymmetric extremal string of five-dimensional minimal supergravity. It also admits an extremal limit when it has maximal rotation in the four-dimensional transverse space. The decoupling limit of our general black string is a BTZ black hole times a two sphere. The macroscopic entropy of the string is reproduced by the Maldacena-Strominger-Witten CFT in appropriate ranges of the parameters. When the pressureless condition is imposed, our string describes the infinite radius limit of the most general class of black rings of minimal supergravity. We discuss implications our solution has for extremal and non-extremal black rings of minimal supergravity.