Spontaneous Symmetry Breaking To GR in SO(4,2) Gravitational Yang-Mills Theory

TL;DR

This paper develops a gauge theory of gravity based on the conformal group SO(4,2), demonstrating how spontaneous symmetry breaking can generate fundamental constants and lead to Einstein gravity with a cosmological constant.

Contribution

It introduces a Yang-Mills type gauge theory of gravity with spontaneous symmetry breaking that reproduces Einstein gravity and cosmological constant from fundamental scalar and gauge fields.

Findings

Emergent Einstein gravity with cosmological constant from SO(4,2) gauge theory.

Explicit spherically symmetric cosmological solution reducing to $ ext{Λ}$FRW.

Fundamental constants derived from scalar field vacuum expectation value.

Abstract

We consider a Yang-Mills type gauge theory of gravity based on the conformal group SO(4,2) coupled to a conformally invariant real scalar field. The goal is to generate fundamental dimensional constants via spontaneous breakdown of the conformal symmetry. In the absence of other matter couplings the resulting theory resembles Weyl-Einstein gravity, {with the Newton constant given by the square of the (constant) vacuum expectation value of the scalar, the cosmological constant determined by the quartic coupling constant of the scalar field and the Weyl to Einstein transition scale determined by the Yang-Mills coupling constant.} The emergent theory in the long-wave-length limit is Einstein gravity with cosmological constant. As an illustrative example we present an exact spherically symmetric cosmological solution with perfect fluid energy-momentum tensor that reduces to $\Lambda$FRW in the long-wavelength limit.