Singularities in wavy strings

TL;DR

This paper investigates the singularity structure of extremal six-dimensional black strings with wave momentum, revealing that quantum effects cause divergences at the horizon affecting test strings.

Contribution

It demonstrates that quantum corrections induce divergences at the horizon of extremal black strings with wave momentum, highlighting the importance of quantum effects in such geometries.

Findings

Curvature invariants remain finite at the horizon in classical solutions.

Quantum effects cause divergence of curvature invariants at the horizon.

Test strings experience divergent excitations due to the singularity.

Abstract

Extremal six-dimensional black string solutions with some non-trivial momentum distribution along the wave are considered. These solutions were recently shown to contain a singularity at the would-be position of the event horizon. In the black string geometry, all curvature invariants are finite at the horizon. It is shown that if the effects of infalling matter are included, there are curvature invariants which diverge there. This implies that quantum corrections will be important at the would-be horizon. The effect of this singularity on test strings is also considered, and it is shown that it leads to a divergent excitation of the string. The quantum corrections will therefore be important for test objects.