Quantum-wave equation and Heisenberg inequalities of covariant quantum gravity

TL;DR

This paper develops a covariant quantum gravity wave equation based on Hamilton-Jacobi quantization, deriving quantum hydrodynamic equations and establishing generalized Heisenberg inequalities for quantum observables in a background space-time.

Contribution

It introduces a manifestly-covariant quantum wave equation for gravity, derived via Hamilton-Jacobi quantization, and links it to quantum hydrodynamics and uncertainty principles.

Findings

Derivation of covariant quantum gravity wave equation from classical tensor fields.

Establishment of quantum hydrodynamic equations using Madelung representation.

Proof of generalized Heisenberg inequalities for quantum gravitational observables.

Abstract

Key aspects of the manifestly-covariant theory of quantum gravity (Cremaschini and Tessarotto 2015-2017) are investigated. These refer, first, to the establishment of the 4-scalar, manifestly-covariant evolution quantum wave equation, denoted as covariant quantum gravity (CQG) wave equation, which advances the quantum state $\psi $ associated with a prescribed background space-time. In this paper, the CQG-wave equation is proved to follow at once by means of a Hamilton-Jacobi quantization of the classical variational tensor field $g\equiv \left\{ g_{\mu \nu }\right\} $ and its conjugate momentum, referred to as (canonical) $g-$quantization. The same equation is also shown to be variational and to follow from a synchronous variational principle identified here with the quantum Hamilton variational principle. The corresponding quantum hydrodynamic equations are then obtained upon introducing the Madelung representation for $\psi $, which provide an equivalent statistical interpretation of the CQG-wave equation. Finally, the quantum state $\psi $ is proved to fulfill generalized Heisenberg inequalities, relating the statistical measurement errors of quantum observables. These are shown to be represented in terms of the standard deviations of the matric tensor $g\equiv \left\{ g_{\mu \nu }\right\} $ and its quantum conjugate momentum operator.