Cosmological time crystals from Einstein-cubic gravities Xing-Hui Feng, Hyat Huang, Shou-Long Li, H. Lü and Hao Wei Eur. Phys. J. C, 80 11 (2020) 1079 Published online: 22 November 2020 DOI: 10.1140/epjc/s10052-020-08622-3