Hamiltonian formulation of a gravity model from (A)dS Yang-Mills theory

TL;DR

This paper develops a Hamiltonian framework for a gravity model derived from (A)dS Yang-Mills theory, analyzing its constraints, gauge invariances, and physical degrees of freedom, especially in the Poincaré contraction limit.

Contribution

It provides a Hamiltonian analysis of a gravity model from (A)dS Yang-Mills theory, including the constraint algebra and degrees of freedom in the contraction limit.

Findings

In the contraction limit, the constraints generate residual Lorentz gauge invariance.

The components of the AdS potential act as tetrads and Lorentz connections.

The theory has only two propagating degrees of freedom in the non-propagating torsion sector.

Abstract

We study the Hamiltonian formulation of a gravity model obtained from a Yang--Mills theory for a one-parameter family of (A)dS Lie algebras parametrized by $\alpha$, when the family of algebras is contracted to the Poincar\'e algebra in the limit $\alpha \to 0$. We derive the canonical structure and first-class constraints and analyze the resulting algebra in the contraction limit. In this limit, the constraints generate the residual Lorentz gauge invariance, and the components of the AdS potential transform as tetrads and Lorentz connection. Finally, we determine the number of physical degrees of freedom, showing that in the non-propagating torsion sector - selected by a Lorentz-covariant gauge condition preserved under dynamical evolution - the theory exhibits only two propagating degrees of freedom.