Quantum tunneling, adiabatic invariance and black hole spectroscopy Guo-Ping Li, Jin Pu, Qing-Quan Jiang and Xiao-Tao Zu Eur. Phys. J. C, 77 5 (2017) 314 Published online: 17 May 2017 DOI: 10.1140/epjc/s10052-017-4901-y