Analyzing cosmic bubble collisions

Roberto Gobbetti, Matthew Kleban

    Research output: Contribution to journalArticlepeer-review


    We develop a set of controlled, analytic approximations to study the effects of bubble collisions on cosmology. We expand the initial perturbation to the inflaton field caused by the collision in a general power series, and determine its time evolution during inflation in terms of the coefficients in the expansion. In models where the observer's bubble undergoes sufficient slow-roll inflation to solve the flatness problem, in the thin wall limit only one coefficient in the expansion is relevant to observational cosmology, allowing nearly model-independent predictions. We discuss two approaches to determining the initial perturbation to the inflaton and the implications for the sign of the effect (a hot or cold spot on the Cosmic Microwave Background temperature map). Lastly, we analyze the effects of collisions with thick-wall bubbles, i.e. away from the thin-wall limit.

    Original languageEnglish (US)
    Article number025
    JournalJournal of Cosmology and Astroparticle Physics
    Issue number5
    StatePublished - May 2012


    • ination
    • particle physics - cosmology connection
    • quantum cosmology

    ASJC Scopus subject areas

    • Astronomy and Astrophysics


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