Emergence and the Swampland Conjectures

TL;DR

This paper offers a new perspective on the Swampland Conjectures, showing that exponential lightness of particles with large field excursions follows from assumptions about strong coupling scales and loop corrections in quantum gravity.

Contribution

It demonstrates that the exponential behavior of light towers near large field distances naturally arises from assumptions about common strong-coupling scales and loop corrections.

Findings

Exponential lightness of particles is linked to loop corrections and strong coupling.

Super-Planckian field excursions involve order-unity changes in particle masses.

Supports the idea that large field ranges challenge effective field theory validity.

Abstract

The Ooguri-Vafa Swampland Conjectures claim that in any consistent theory of quantum gravity, when venturing to large distances in scalar field space, a tower of particles will become light at a rate that is exponential in the field space distance. We provide a novel viewpoint on this claim: if we assume that a tower of states becomes light near a particular point in field space, and we further demand that loop corrections drive both gravity and the scalar to strong coupling at a common energy scale, then the requirement that the particles become light exponentially fast in the field-space distance in Planck units follows automatically. Furthermore, the same assumption of a common strong-coupling scale for scalar fields and gravitons implies that when a scalar field evolves over a super-Planckian distance, the average particle mass changes by an amount of order the cutoff energy. This supports earlier suggestions that significantly super-Planckian excursions in field space cannot be described within a single effective field theory. We comment on the relationship of our results to the Weak Gravity Conjecture.