Gravity-induced four-fermion contact interaction implies gravitational intermediate W and Z type gauge bosons

TL;DR

The paper proposes that extending Einstein-Cartan gravity with quadratic kinetic terms introduces massive gravitational gauge bosons analogous to W and Z bosons, stemming from four-fermion interactions.

Contribution

It introduces a novel extension of Einstein-Cartan gravity that predicts new massive gravitational gauge bosons similar to electroweak W and Z particles.

Findings

Quadratic kinetic terms lead to propagating gravitational degrees of freedom.

Massive gravitational gauge bosons emerge from four-fermion interactions.

Analogy with Fermi's four-fermion interaction and electroweak bosons.

Abstract

Coupling fermions to gravity necessarily leads to a non-renormalizable, gravitational four-fermion contact interaction. In this essay, we argue that augmenting the Einstein-Cartan Lagrangian with suitable kinetic terms quadratic in the gravitational gauge field strengths (torsion and curvature) gives rise to new, massive propagating gravitational degrees of freedom. This is to be seen in close analogy to Fermi's effective four-fermion interaction and its emergent W and Z bosons.