The Top 10^{500} Reasons Not to Believe in the Landscape

TL;DR

This paper challenges the string landscape concept, proposing a limited set of non-perturbative AdS solutions, and argues that eternal inflation relies on anthropic reasoning incompatible with experimental data.

Contribution

It introduces a plausible landscape of supergravity solutions and critiques the eternal inflation paradigm, emphasizing the role of quantum gravity and holography.

Findings

String landscape is a fantasy with limited solutions.

Eternal inflation relies on anthropic principles incompatible with experiments.

Finite instantons govern cutoff-independent physics in de Sitter space.

Abstract

The String Landscape is a fantasy. We actually have a plausible landscape of minimally supersymmetric $AdS_4$ solutions of supergravity modified by an exponential superpotential. None of these solutions is accessible to world sheet perturbation theory. If they exist as models of quantum gravity, they are defined by conformal field theories, and each is an independent quantum system, which makes no transitions to any of the others. This landscape has nothing to do with CDL tunneling or eternal inflation. A proper understanding of CDL transitions in QFT on a fixed background dS space, shows that the EI picture of this system is not justified within the approximation of low energy effective field theory. The cutoff independent physics, defined by the Euclidean functional integral over the 4-sphere admits only a finite number of instantons. Plausible extensions of these ideas to a quantum theory of gravity obeying the holographic principle explain all of the actual facts about CDL transitions in dS space, and lead to a picture radically different from eternal inflation. Theories of Eternal Inflation (EI) have to rely too heavily on the anthropic principle to be consistent with experiment. Given the vast array of effective low energy field theories that could be produced by the conventional picture of the string landscape one is forced to conclude that the most numerous anthropically allowed theories will disagree with experiment violently.