Gravity and axions from a random UV QFT

TL;DR

This paper explores how a large, random UV quantum field theory can naturally give rise to 4D gravity and axions, with implications for the equivalence principle and axion scale.

Contribution

It proposes that coupling the Standard Model to a vast, random UV QFT naturally produces gravity and axions, linking the axion decay constant to the Planck scale and the number of colors.

Findings

Massless 4D gravity emerges from the UV QFT.

Axions are a generic feature of the UV QFT coupling.

The axion decay constant scales as $f=M_P/N$, relating it to the Planck scale and the number of colors.

Abstract

It is postulated that the UV QFT is enormous and random. The coupling of the Standard Model to such QFT is analyzed. It is argued that massless 4d gravity and axions are general avatars of the postulate. The equivalence principle emerges naturally as well as a concrete set of sources for its breaking. The axion scale is related to the 4d Planck scale as $f=M_P/N$, where $N$ is the "number of colors" of the (almost) hidden UV CFT.