Gravity from a fermionic condensate of a gauge theory

TL;DR

This paper proposes that gravity can be modeled as a gauge theory with a spontaneously broken de Sitter symmetry, achieved through a fermionic condensate of spinors, aligning with Einstein-Cartan gravity.

Contribution

It introduces a novel mechanism where a fermionic condensate naturally breaks de Sitter symmetry in gauge theories of gravity, providing a physically realistic symmetry-breaking process.

Findings

Fermionic condensate is compatible with Einstein-Cartan equations.

The condensate can be imposed in a de Sitter invariant manner.

Supports gravity as a gauge theory with spontaneous symmetry breaking.

Abstract

The most prominent realization of gravity as a gauge theory similar to the gauge theories of the standard model comes from enlarging the gauge group from the Lorentz group to the de Sitter group. To regain ordinary Einstein-Cartan gravity the symmetry must be broken, which can be accomplished by known quasi-dynamic mechanisms. Motivated by symmetry breaking models in particle physics and condensed matter systems, we propose that the symmetry can naturally be broken by a homogenous and isotropic fermionic condensate of ordinary spinors. We demonstrate that the condensate is compatible with the Einstein-Cartan equations and can be imposed in a fully de Sitter invariant manner. This lends support, and provides a physically realistic mechanism for understanding gravity as a gauge theory with a spontaneously broken local de Sitter symmetry.