Observational implications of cosmological event horizons

Nemanja Kaloper, Matthew Kleban, Lorenzo Sorbo

    Research output: Contribution to journalArticlepeer-review


    In a universe dominated by a small cosmological constant or by eternal dark energy with equation of state ω <-1/3, observers are surrounded by event horizons. The horizons limit how much of the universe the observers can ever access. We argue that this implies a bound N∼60 on the number of e-folds of inflation that will ever be observable in our universe if the scale of the dark energy today is ∼(10 -3 eV) 4. This bound is independent of how long inflation lasted, or for how long we continue to observe the sky. The bound arises because the imprints of the inflationary perturbations thermalize during the late acceleration of the universe. They "inflate away" just like the initial inhomogeneities during ordinary inflation. Thus the current CMB data may be looking as far back in the history of the universe as will ever be possible, making our era a most opportune time to study cosmology.

    Original languageEnglish (US)
    Pages (from-to)7-14
    Number of pages8
    JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
    Issue number1-2
    StatePublished - Oct 21 2004

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics


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