The Holographic Universe

TL;DR

This paper introduces a holographic approach to modeling four-dimensional inflationary universes using three-dimensional quantum field theories, offering new insights into early universe cosmology and primordial perturbations.

Contribution

It develops a holographic framework for inflationary universes, including models with strongly coupled gravity, and proposes a novel method for generating scale-invariant primordial spectra.

Findings

Holographic models reproduce standard inflationary predictions.

Models with strongly coupled gravity can satisfy observational constraints.

New phenomenology for primordial perturbations is demonstrated.

Abstract

We present a holographic description of four-dimensional single-scalar inflationary universes in terms of a three-dimensional quantum field theory. The holographic description correctly reproduces standard inflationary predictions in their regime of applicability. In the opposite case, wherein gravity is strongly coupled at early times, we propose a holographic description in terms of perturbative QFT and present models capable of satisfying the current observational constraints while exhibiting a phenomenology distinct from standard inflation. This provides a qualitatively new method for generating a nearly scale-invariant spectrum of primordial cosmological perturbations.