In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature TRH∼(ΓφMP)1/2 where Γφ is the inflaton decay rate. We consider the effect of particle production at temperatures at or near the maximum temperature attained during reheating. We show that the impact of this early production on the final particle abundance depends strongly on the temperature dependence of the production cross section. For σv ∼Tn/Mn+2, and for n<6, any particle produced at Tmax is diluted by the later generation of entropy near TRH. This applies to cases such as gravitino production in low scale supersymmetric models (n=0) or NETDM models of dark matter (n=2). However, for n≥6 the net abundance of particles produced during reheating is enhanced by over an order of magnitude, dominating over the dilution effect. This applies, for instance to gravitino production in high scale supersymmetry models where n=6.
Bibliographical noteFunding Information:
This work was supported by the France-US PICS No. 06482. Y. M. acknowledges partial support from the European Union’s Horizon 2020 research and innovation program under Marie Sklodowska-Curie Grants No. 690575 and No. 674896 and ERC advanced grants Higgs@LHC. The work of K. A. O. and M. P. was supported in part by DOE Grant No. DE–SC0011842 at the University of Minnesota. The work of M. A. G. G. was partially completed at the Aspen Center for Physics, which is supported by National Science Foundation Grant No. PHY-1066293. M. A. G. G. acknowledges support from the U.S. Department of Energy Grant No. DE-SC0018216. M. A. G. G. would like to thank M. A. Amin for helpful discussions.
© 2017 American Physical Society.