The limit y of the incident particle under the superradiance of Kerr black hole

It is important to emphasize that as the reference has proved well, the critical storage line of black hole field system is universal, that is, different scalar field coupling functions with the same weak field behavior are $\{C(\phi) \} , C (\phi) =1+\alpha\phi ^{2} + o(\phi ^{4})$, and have the same function behavior $\alpha=\alpha (\mu); a / M) $. The purpose of this paper is to find out the limit $y$ of the incident particle under the superradiance of the preset boundary (${\mu} = {y}{\omega}$).