Analytical calculation of Kerr and Kerr-Ads black holes in f(R) theory Ping Li, Yong-qiang Liu, Jiang-he Yang, Siwei Xu and Xiang-hua Zhai Eur. Phys. J. C, 84 7 (2024) 704 Published online: 16 July 2024 DOI: 10.1140/epjc/s10052-024-13074-0