Events

Theory Seminar (High Energy/Cosmology)

<< Summer 2023 Fall 2023 Spring 2024 >>
Subscribe your calendar or receive email announcements of events
Cosmological gravitational particle production of massive spin-2 particles
Date: Friday, October 13th
Time: 1:00 pm - 2:00 pm
Place: Chamberlin 5310
Speaker: Siyang Ling, Rice University
Abstract: The 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 result 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.
Host: Yoshihiko Abe
Add this event to your calendar