A Symmetry-centric Perspective on the Geometry of the String Landscape and the Swampland

TL;DR

This paper explores the geometric and symmetry properties of scalar field moduli spaces in quantum gravity, linking universal features to generalized global symmetries and their gauging or breaking.

Contribution

It offers a modern reformulation of the Ooguri-Vafa conjectures using generalized global symmetries in the context of quantum gravity.

Findings

Scalar moduli spaces are infinite in diameter and have trivial fundamental group.

Universal features can be explained via gauging or breaking of symmetries.

Connections between geometry and symmetry principles in quantum gravity are established.

Abstract

As famously observed by Ooguri and Vafa nearly twenty years ago, scalar field moduli spaces in quantum gravity appear to exhibit various universal features. For instance, they seem to be infinite in diameter, have trivial fundamental group, and feature towers of massive particles that become light in their asymptotic limits. In this essay, we explain how these features can be reformulated in more modern language using generalized notions of global symmetries. Such symmetries are ubiquitous in non-gravitational quantum field theories, but it is widely believed that they must be either gauged or broken in quantum gravity. In what follows, we will see that the observations of Ooguri and Vafa can be understood as consequences of such gauging or breaking.