Elastic instability of black rings at large D

Understand

Using the inverse dimensional expansion method we study the elastic instability of black rings found recently in numerical analysis of fully nonlinear dynamical evolutions.

• In our analysis we should perform 1/D^1/2 expansions, not usual 1/D expansions, of the Einstein equations to capture this elastic instability of D dimensional black rings.
• By solving the Einstein equations at large D we obtain the effective equations for black rings, and the perturbation analysis of the large D effective equations with 1/D^1/2 expansions yields the formula for quasinormal mode frequencies.
• From this formula, we find that black rings actually suffer from both elastic and Gregory-Laflamme like instabilities.