A note about a pure spin-connection formulation of General Relativity and spin-2 duality in (A)dS

TL;DR

This paper explores a pure spin-connection formulation of General Relativity with a cosmological constant, revealing a Weyl-like quadratic Lagrangian at the linear level and establishing a duality with massive gravitons in (A)dS space.

Contribution

It introduces a pure spin-connection approach to GR with a cosmological constant and demonstrates a duality with massive gravitons in (A)dS space, providing new insights into the theory's structure.

Findings

Pure spin-connection quadratic Lagrangian resembles Weyl gravity.

Dual gauge field transforms as a massive graviton in (A)dS.

Physical degrees of freedom correspond to a massless graviton.

Abstract

We investigate the problem of finding a pure spin-connection formulation of General Relativity with non-vanishing cosmological constant. We first revisit the problem at the linearised level and find that the pure spin-connection, quadratic Lagrangian, takes a form reminiscent to Weyl gravity, given by the square of a Weyl-like tensor. Upon Hodge dualisation, we show that the dual gauge field in (A)dS$_D$ transforms under $GL(D)$ in the same representation as a massive graviton in the flat spacetime of the same dimension. We give a detailed proof that the physical degrees of freedom indeed correspond to a massless graviton propagating around the (anti-) de Sitter background and finally speculate about a possible nonlinear pure-connection theory dual to General Relativity with cosmological constant.