Cosmological perturbations from inhomogeneous reheating, freeze-out, and mass domination

2003/05/28 by Gia Dvali, Andrei Gruzinov, Matias Zaldarriaga +1 · 13 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph

paper · pdf · doi:10.1103/physrevd.69.083505

published as Phys.Rev.D69:083505,2004 · 13 pages

arxiv created 2003/05/28 · openalex publication_date 2004/04/05 · arxiv updated 2010/04/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We generalize a recently proposed mechanism for the origin of primordial metric perturbations in inflationary models. Quantum fluctuations of light scalar fields during inflation gives rise to superhorizon fluctuations of masses and reaction rates of various particles. Reheating, freeze-out, and matter-domination processes become inhomogeneous and generate superhorizon metric perturbations. We also calculate the degree of non-Gaussianity f_nl for this new model of cosmological perturbations. The precise value of f_nl depends on the specific models, but |f_nl|\ensuremath∼few is a natural lower bound for our mechanisms. This is much larger than the currently assumed theoretical value f_nl\ensuremath∼tilt\ensuremath\lesssim0.05, and is thought to be observable. In a particularly attractive model of inhomogeneous mass domination, the non-Gaussianity of perturbations generated by our mechanism is simply f_nl=5, irrespective of the detailed structure of the underlying field theory.

Citations

• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Parametric amplification of metric fluctuations during reheating in two field models

Cited by

• On the non-Gaussianity from recombination
• Seeding of primordial perturbations during a decelerated expansion
• Evolution of the curvature perturbations during warm inflation
• Right-handed neutrinos as the source of density perturbations
• Hybrid inflation without flat directions and without primordial black holes
• DUALITY INVARIANCE AND COSMOLOGICAL DYNAMICS
• Hilltop inflation
• Non‐Gaussianity from Particle Production during Inflation
• Scale of gravity and the cosmological constant within a landscape
• On the generation of a non-gaussian curvature perturbation during preheating
• Non-gaussian mode coupling and the statistical cosmological principle
• Critical Number of Fields in Stochastic Inflation
• Limits on second-order non-Gaussianity from Minkowski functionals of WMAP 7-year data