A new Om(z) diagnostic of dark energy in general relativity theory N. Myrzakulov, M. Koussour and Dhruba Jyoti Gogoi Eur. Phys. J. C, 83 7 (2023) 594 Published online: 11 July 2023 DOI: 10.1140/epjc/s10052-023-11794-3