Does Inflation Provide Natural Initial Conditions for the Universe?

Abstract

If our universe underwent inflation, its entropy during the inflationary phase was substantially lower than it is today. Because a low-entropy state is less likely to be chosen randomly than a high-entropy one, inflation is unlikely to arise through randomly-chosen initial conditions. To resolve this puzzle, we examine the notion of a natural state for the universe, and argue that it is a nearly-empty spacetime. If empty space has a small vacuum energy, however, inflation can begin spontaneously in this background. This scenario explains why a universe like ours is likely to have begun via a period of inflation, and also provides an origin for the cosmological arrow of time.

Submitted to Gravity Research Foundation Essay Competition; based on hep-th/0410270

References in corpus (3)

• Can the universe afford inflation?
• Spontaneous Inflation and the Origin of the Arrow of Time
• Inflation without a beginning: a null boundary proposal

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• Smooth Initial Conditions from Weak Gravity
• Thermodynamics of Shearing Massless Scalar Field Spacetimes is Inconsistent With the Weyl Curvature Hypothesis
• Upper and Lower Bounds on Gravitational Entropy
• CPTM symmetry, closed time paths and cosmological constant problem in the formalism of extended manifold
• From Cosmos to Intelligent Life: The Four Ages of Astrobiology
• Inflation as a Solution to the Early Universe Entropy Problem
• Inflation and Dark Matter from The Low Entropy Hypothesis and Modeling Mechanism of Modified Gravity
• Time, Incompleteness and Singularity in Quantum Cosmology