Populating the Landscape: A Top Down Approach

Abstract

We put forward a framework for cosmology that combines the string landscape with no boundary initial conditions. In this framework, amplitudes for alternative histories for the universe are calculated with final boundary conditions only. This leads to a top down approach to cosmology, in which the histories of the universe depend on the precise question asked. We study the observational consequences of no boundary initial conditions on the landscape, and outline a scheme to test the theory. This is illustrated in a simple model landscape that admits several alternative inflationary histories for the universe. Only a few of the possible vacua in the landscape will be populated. We also discuss in what respect the top down approach differs from other approaches to cosmology in the string landscape, like eternal inflation.

22 pages, 1 figure

References in corpus (4)

• The Anthropic Landscape of String Theory
• Probing String Theory with Modulated Cosmological Fluctuations
• Loop Quantum Gravity and the Cyclic Universe
• Landskepticism: or Why Effective Potentials Don't Count String Models

Cited by in corpus (15)

• Inflationary Cosmology
• The Measure Problem in Cosmology
• Sinks in the Landscape, Boltzmann Brains, and the Cosmological Constant Problem
• The Classical Universes of the No-Boundary Quantum State
• The No-Boundary Measure of the Universe
• A measure of the multiverse
• Islands in the landscape
• Dynamics of false vacuum bubbles with nonminimal coupling
• Probabilities in the landscape
• Replication Regulates Volume Weighting in Quantum Cosmology
• Vacuum Bubble in an Inhomogeneous Cosmology
• A Note on the Quantum Creation of Universes
• No-Bang Quantum State of the Cosmos
• Abelian Varieties, RCFTs, Attractors, and Hitchin Functional in Two Dimensions
• The No-Boundary Probability for the Universe starting at the top of the hill