The Generalized Scalar Weak Gravity Conjecture and its Implications

TL;DR

This paper introduces a generalized version of the Scalar Weak Gravity Conjecture, exploring its implications for particle physics, including constraints on axion couplings and the scale of new physics in the Standard Model Higgs sector.

Contribution

It formulates a generalized Scalar Weak Gravity Conjecture inspired by the gauge case and analyzes its phenomenological consequences for axions and the Higgs sector.

Findings

Most axion-nucleon coupling parameter space is ruled out.

Constraints on axion couplings to fermions and photons are tightened.

Implications for the scale of new physics in the Standard Model Higgs sector.

Abstract

We propose a generalized formulation of the Scalar Weak Gravity Conjecture (SWGC) based on the analogy with the derivation of the Gauge Weak Gravity Conjecture (GWGC). We discuss some phenomenological implications of this Generalized SWGC, including the scale of New Physics (NP) when applied to the SM Higgs sector, and the bounds on the axion's couplings to fermions and the photon when applied to the axion. The Generalized SWGC constraints rule out most of the parameter space of axion-nucleon couplings, leaving only a tiny parameter space.