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

Gia Dvali, Andrei Gruzinov, Matias Zaldarriaga

    Research output: Contribution to journalArticle

    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 fn l for this new model of cosmological perturbations. The precise value of fn l depends on the specific models, but |n l|∼few is a natural lower bound for our mechanisms. This is much larger than the currently assumed theoretical value fn l∼-tilts≲ 0.05, 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 n l = 5, irrespective of the detailed structure of the underlying field theory.

    Original languageEnglish (US)
    Article number083505
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Volume69
    Issue number8
    DOIs
    StatePublished - 2004

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    perturbation
    heating
    reaction kinetics
    scalars

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

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    Cosmological perturbations from inhomogeneous reheating, freeze-out, and mass domination. / Dvali, Gia; Gruzinov, Andrei; Zaldarriaga, Matias.

    In: Physical Review D - Particles, Fields, Gravitation and Cosmology, Vol. 69, No. 8, 083505, 2004.

    Research output: Contribution to journalArticle

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