Cosmology at the end of the world

TL;DR

This paper explores how cosmological physics can be studied within the AdS/CFT framework by modeling our universe as a brane in a higher-dimensional spacetime, enabling insights into quantum cosmology.

Contribution

It demonstrates a microscopic realization of braneworld cosmology in AdS/CFT using special field theory states dual to an end-of-the-world brane in a charged black hole spacetime.

Findings

Observers on the brane experience cosmological physics.

The model reproduces approximately four-dimensional gravity.

It opens pathways for quantum simulation of cosmology.

Abstract

In the last two decades the Anti-de Sitter/Conformal Field Theory correspondence (AdS/CFT) has emerged as focal point of many research interests. In particular, it functions as a stepping stone to a still missing full quantum theory of gravity. In this context, a pivotal question is if and how cosmological physics can be studied using AdS/CFT. Motivated by string theory, braneworld cosmologies propose that our universe is a four-dimensional membrane embedded in a bulk five-dimensional AdS spacetime. We show how such a scenario can be microscopically realized in AdS/CFT using special field theory states dual to an "end-of-the-world brane" moving in a charged black hole spacetime. Observers on the brane experience cosmological physics and approximately four-dimensional gravity, at least locally in spacetime. This result opens a new path towards a description of quantum cosmology and the simulation of cosmology on quantum machines.