Photon orbits and phase transitions in Kiselev-AdS black holes from gravity Ashima Sood, Arun Kumar, J. K. Singh and Sushant G. Ghosh Eur. Phys. J. C, 84 8 (2024) 876 Published online: 30 August 2024 DOI: 10.1140/epjc/s10052-024-13251-1