Spacetime in String Theory

TL;DR

This paper reviews how string theory suggests spacetime is not fundamental but emerges from a holographic dual, differing significantly from Einstein's relativity, especially in nonperturbative regimes.

Contribution

It provides an overview of the emergent nature of spacetime in string theory, highlighting differences between perturbative and nonperturbative perspectives.

Findings

Spacetime appears as coupling constants in a 2D quantum field theory.

Nonperturbatively, spacetime is reconstructed from a holographic dual.

Spacetime is not fundamental but emergent in string theory.

Abstract

We give a brief overview of the nature of spacetime emerging from string theory. This is radically different from the familiar spacetime of Einstein's relativity. At a perturbative level, the spacetime metric appears as ``coupling constants" in a two dimensional quantum field theory. Nonperturbatively (with certain boundary conditions), spacetime is not fundamental but must be reconstructed from a holographic, dual theory.