Noncommutative Quantum Gravity

TL;DR

This paper explores a framework for noncommutative quantum gravity using complex metrics and noncommuting spacetime coordinates, aiming to unify gravity with quantum principles through a novel geometric approach.

Contribution

It introduces a complex symmetric metric and a noncommutative spacetime geometry with a real action, advancing the formulation of noncommutative quantum gravity.

Findings

Complex symmetric metric with associated connection and curvature.

Spacetime coordinates are generally complex, with gauge group CSO(3,1).

A Weyl quantization approach is employed for the metric.

Abstract

The possible role of gravity in a noncommutative geometry is investigated. Due to the Moyal *-product of fields in noncommutative geometry, it is necessary to complexify the metric tensor of gravity. We first consider the possibility of a complex Hermitian, nonsymmetric $g_{\mu\nu}$ and discuss the problems associated with such a theory. We then introduce a complex symmetric (non-Hermitian) metric, with the associated complex connection and curvature, as the basis of a noncommutative spacetime geometry. The spacetime coordinates are in general complex and the group of local gauge transformations is associated with the complex group of Lorentz transformations CSO(3,1). A real action is chosen to obtain a consistent set of field equations. A Weyl quantization of the metric associated with the algebra of noncommuting coordinates is employed.