Neutral Black Rings in Five Dimensions are Unstable

Area of Science:

• General Relativity
• Black Hole Physics
• Gravitational Dynamics

Background:

• Emparan-Reall black rings are theoretical solutions in general relativity.
• Previous studies suggested instability in 'fat' black rings using Penrose inequalities.

Purpose of the Study:

• To investigate the stability of Emparan-Reall black rings under nonaxisymmetric gravitational perturbations.
• To numerically determine the stability properties across the black ring's parameter space.

Main Methods:

• Numerical simulations of nonaxisymmetric linearized gravitational perturbations.
• Analysis of perturbation modes across different black ring geometries ('fat' and 'thin' branches).

Main Results:

• An unstable mode was identified in the 'fat' black ring branch.
• This instability was found to extend into the 'thin' black ring branch.
• Numerical evidence supports the instability of the entire black ring family.

Conclusions:

• The Emparan-Reall black ring family is numerically confirmed to be unstable.
• Instability is a characteristic feature across both 'fat' and 'thin' black ring solutions.