Nonlinear instability conjecture for anti-de Sitter spacetime with reflecting boundary conditions

The pure anti-de Sitter spacetime is considered with reflecting boundary conditions, namely Dirichlet or Neumann conditions. Nonlinear instability conjecture. Anti-de Sitter spacetime is non-linearly unstable for reflecting (Dirichlet or Neumann) boundary conditions. This conjecture, attributed in the source to Holzegel and Dafermos, concerns the nonlinear dynamics of anti-de Sitter spacetime under reflecting conditions and remains open in the supplied text.