Kolb, Edward W.Ling, SiyangLong, Andrew J.Rosen, Rachel A.2023-07-212023-07-212023Kolb, Edward W., Ling, Siyang, Long, Andrew J., et al.. "Cosmological gravitational particle production of massive spin-2 particles." <i>Journal of High Energy Physics,</i> 2023, (2023) Springer Nature: https://doi.org/10.1007/JHEP05(2023)181.https://hdl.handle.net/1911/115003The phenomenon of cosmological gravitational particle production (CGPP) is expected to occur during the period of inflation and the transition into a hot big bang cosmology. Particles may be produced even if they only couple directly to gravity, and so CGPP provides a natural explanation for the origin of dark matter. In this work we study the gravitational production of massive spin-2 particles assuming two different couplings to matter. We evaluate the full system of mode equations, including the helicity-0 modes, and by solving them numerically we calculate the spectrum and abundance of massive spin-2 particles that results from inflation on a hilltop potential. We conclude that CGPP might provide a viable mechanism for the generation of massive spin-2 particle dark matter during inflation, and we identify the favorable region of parameter space in terms of the spin-2 particle’s mass and the reheating temperature. As a secondary product of our work, we identify the conditions under which such theories admit ghost or gradient instabilities, and we thereby derive a generalization of the Higuchi bound to Friedmann-Robertson-Walker (FRW) spacetimes.engExcept where otherwise noted, this work is licensed under a Creative Commons Attribution (CC BY) license.  Permission to reuse, publish, or reproduce the work beyond the terms of the license or beyond the bounds of Fair Use or other exemptions to copyright law must be obtained from the copyright holder.Journal articlejhep05-2023-181https://doi.org/10.1007/JHEP05(2023)181