Kolb, Edward W ; Ling, Siyang ; Long, Andrew J. Kolb, Edward W., Ling, Siyang, Long, Andrew J., et al. "Cosmological gravitational particle production of massive spin-2 particles." Journal of High Energy Physics, 2023, (2023) Springer Nature: https://doi.org/10.1007/JHEP05(2023)181..
,
2023