Testing Kerr black hole mimickers with quasi-periodic oscillations from GRO J1655-40 Xin Jiang, Peng Wang, Houwen Wu and Haitang Yang Eur. Phys. J. C, 81 11 (2021) 1043 Published online: 27 November 2021 DOI: 10.1140/epjc/s10052-021-09816-z