On the strong-CP problem and its axion solution in torsionful theories

TL;DR

This paper explores how torsion in gravitational theories could offer a natural protection mechanism for the axion solution to the strong-CP problem, addressing potential gravitational interference.

Contribution

It introduces the idea that torsion-related axion-like fields can safeguard the axion solution from gravitational effects.

Findings

Torsion may generate an additional axion-like field.

Gravity's interference with the axion solution can be mitigated by torsion.

Proposes a new mechanism for protecting the axion solution in gravitational theories.

Abstract

Gravitational effects may interfere with the axion solution to the strong-CP problem. We point out that gravity can potentially provide a protection mechanism against itself, in the form of an additional axion-like field associated with torsion.