Eternal Inflation: The Inside Story

Abstract

Motivated by the lessons of black hole complementarity, we develop a causal patch description of eternal inflation. We argue that an observer cannot ascribe a semiclassical geometry to regions outside his horizon, because the large-scale metric is governed by the fluctuations of quantum fields. In order to identify what is within the horizon, it is necessary to understand the late time asymptotics. Any given worldline will eventually exit from eternal inflation into a terminal vacuum. If the cosmological constant is negative, the universe crunches. If it is zero, then we find that the observer's fate depends on the mechanism of eternal inflation. Worldlines emerging from an eternal inflation phase driven by thermal fluctuations end in a singularity. By contrast, if eternal inflation ends by bubble nucleation, the observer can emerge into an asymptotic, locally flat region. As evidence that bubble collisions preserve this property, we present an exact solution describing the collision of two bubbles.

17 pages, 12 figures; v2, PRD format

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• The holographic principle
• Decoherence, the measurement problem, and interpretations of quantum mechanics
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• The Stretched Horizon and Black Hole Complementarity
• The Cold Dark Matter Density Perturbation
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• Holographic probabilities in eternal inflation
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• Why Comparable? A Multiverse Explanation of the Dark Matter-Baryon Coincidence
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• The Census Taker's Hat
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• de Sitter as a Resonance
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• On the Topological Phases of Eternal Inflation
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• Fractal-Flows and Time's Arrow
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• de Sitter Harmonies: Cosmological Spacetimes as Resonances
• String Gases and the Swampland
• Rejuvenating the hope of a swampland consistent inflated multiverse with tachyonic inflation in the high energy RS-II Braneworld
• Agnesi Weighting for the Measure Problem of Cosmology
• Eternal inflation in light of Wheeler-DeWitt equation
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