%0 Journal Article
%T Collapse of Small-Scale Density Perturbations during Preheating in Single Field Inflation
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%+ Institut d'Astrophysique de Paris (IAP)
%A Jedamzik, Karsten
%A Lemoine, Martin
%A Martin, Jerome
%< avec comité de lecture
%Z LPTA:10-009
%@ 1475-7508
%J Journal of Cosmology and Astroparticle Physics
%I Institute of Physics (IOP)
%V 09
%P 034
%8 2010-09-30
%D 2010
%Z 1002.3039
%R 10.1088/1475-7516/2010/09/034
%K Inflation
%K physics of the early universe
%K cosmological perturbation theory
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]
%Z Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
%Z Physics [physics]/High Energy Physics - Theory [hep-th]Journal articles
%X After cosmic inflation and before the transition to radiation domination, the cosmic energy density may have been dominated during an extended period by an oscillating massive scalar condensate. We show that during this period, sub-Hubble scale perturbations are subject to a metric preheating instability in the narrow resonance regime. We analyze in detail both, quadratic and quartic potentials. The instability leads to the growth of density perturbations which in many cases become non-linear already before the beginning of a radiation dominated Universe. This is particularly the case when requiring a phenomenologically preferred low reheat temperature. These early structures may lead to the emission of gravitational waves and the production of primordial black holes. Furthermore, it is not clear if they could modify the prediction of linear curvature perturbations on very large scales.
%G English
%L hal-00460778
%U https://hal.science/hal-00460778
%~ IN2P3
%~ INSU
%~ UPMC
%~ LPTA
%~ CNRS
%~ UNIV-MONTP2
%~ IAP
%~ UPMC_POLE_2
%~ UNIV-MONTPELLIER
%~ SORBONNE-UNIVERSITE
%~ SU-SCIENCES
%~ SU-TI
%~ ALLIANCE-SU
%~ UM1-UM2