Quasinormal modes around the BTZ black hole at the tricritical generalized massive gravity

Employing the operator method, we obtain log-square quasinormal modes and frequencies of a graviton around the Banados-Teitelboim-Zanelli (BTZ) black hole at the tricritical point of the generalized massive gravity. The log-square quasinormal frequencies are also obtained by considering a finite temperature conformal field theory. This shows the AdS/LCFT correspondence at the tricritical point approximately. We discuss a truncation process to the unitary theory on the BTZ black hole background.