2007/11/30 by Yuki Watanabe, Eiichiro Komatsu · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Electroweak interaction #Gravitation #Hierarchy problem #Inflation (cosmology) #Inflaton #Particle physics #Physics #Quantum #Quantum gravity #Quantum mechanics #Theoretical physics #Universe #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.77.043514
published as Phys.Rev.D77:043514,2008 · 6 pages, submitted to PRD, (v2) references added, (v3) revised to have inflaton quanta canonically normalized
openalex publication_date 2008/02/14 · arxiv created 2008/04/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study implications of the large-N species solution to the hierarchy problem, proposed by G. Dvali, for reheating of the Universe after inflation. Dvali's proposal contains additional N\ensuremath∼1032Z2-conserved quantum fields beyond the standard model particles with mass \ensuremath∼1 TeV, which weaken gravity by a factor of 1/N, and thus explain the hierarchy between the Plank scale and the electroweak scale. We show that, in this scenario, the decay rates of inflaton fields through gravitational decay channels are enhanced by a factor of N, and thus they decay into N species of the quantum fields very efficiently, in the limit that quantum gravity effects are unimportant for the gravitational decay rate. In order not to violate energy conservation or over-reheat the Universe, inflaton mass, vacuum expectation value of inflaton, or nonminimal gravitational coupling should be tightly fine-tuned. Our conclusion holds even when the gravitational decay is prohibited by some symmetry of the theory; the Universe may still be over-reheated via annihilation of inflatons, if the number density of inflaton quanta is greater than the critical value.